Fedora 16 To Use Btrfs Filesystem By Default

Cool. by Anonymous Coward · 2011-06-09 02:09 · Score: 3, Funny

Can't wait to turn all my files into butter.

Re:Cool. by Anonymous Coward · 2011-06-09 04:16 · Score: 0

Don't worry, you can run fsck.btrfs to fi... oh.. wait... that command doesn't actually repair anything yet.
Re:Cool. by Anonymous Coward · 2011-06-09 04:56 · Score: 0

GLADoS says:
The secret to truly cynical cake is extra salt in the password hash
Re:Cool. by jetole · 2011-06-09 06:25 · Score: 5, Insightful

Turn your files into butter is right. Though I don't use Fedora, I was interested to look into btrfs again when I read this post on slashdot.

Much to my surprise, directly from the main btrfs wiki: "Note that Btrfs does not yet have a fsck tool that can fix errors. While Btrfs is stable on a stable machine, it is currently possible to corrupt a filesystem irrecoverably if your machine crashes or loses power on disks that don't handle flush requests correctly. This will be fixed when the fsck tool is ready."

Why would RedHat choose such a file system that does not have basic support for recovery of a file system after a system crashes? This has been an essential part of file systems since the as far back as I can remember.
Re:Cool. by jjohnson · 2011-06-09 06:57 · Score: 1

Because it's Fedora, which is explicitly a testbed distro for newer technologies, and the problem is limited to disks that don't handle flush requests correctly. If you care about a 100% reliable system, you shouldn't be using Fedora in the first place. If you're willing to accept a very small risk of losing everything and having to restore from backup, you get to play with the shiny new toys.

--
Anyone who loves or hates any language, platform, or manufacturer, doesn't know what they're talking about.
Re:Cool. by jetole · 2011-06-09 07:13 · Score: 3, Insightful

"a very small risk"? Have you never had a system crash that you have had to reboot? Have you never had to run fsck to scan and correct a disk? Everyone else I know who uses Linux has done both multiple times. This particular "shiny new toys", as you put it, is not production ready if it does not contain fsck capabilities and according to it's authors it does not. When I say "production ready", I am not referring to whether or not it's stable enough to run a production server farm but I mean whether or not it is capable to handle a Linux desktop system that is not designated for beta testing only. I would be happy to run btrfs when everything is complete but right now the authors of btrfs say that a nessecary component for generic system failure issues is not yet complete.
Re:Cool. by jjohnson · 2011-06-09 07:26 · Score: 3, Insightful

You get the reliability you select. All you need to do to avoid this issue with brtfs is 1) use ext4 instead, or 2) use a hard disk that doesn't lie about whether or not it's buffering.
Fedora is not production ready even in the sense of a daily use desktop with data that can't be recovered from backup, even without this problem. It's explicitly a testbed distro, and always has been.

--
Anyone who loves or hates any language, platform, or manufacturer, doesn't know what they're talking about.
Re:Cool. by mark_osmd · 2011-06-09 10:12 · Score: 1

rpm -q --list btrfs-progs | grep btrfsck /sbin/btrfsck /usr/share/man/man8/btrfsck.8.gz The description of that in the man page says: DESCRIPTION btrfsck is used to check a btrfs filesystem. device is the device file where the filesystem is stored. That's in my current install of Fedora 15, maybe the btrfs wiki is stale. They do seem to take their time updating it.
Re:Cool. by jetole · 2011-06-09 10:56 · Score: 1

Well that could be the case @ stale wiki and if so, then that makes a lot more sense for why Red Hat would choose it. The wiki page should be updated though because that stale wiki would have completely turned me off btrfs for a long time. In this case, I retract what I said if there is in fact fsck capabilities for btrfs.
Re:Cool. by makomk · 2011-06-09 12:54 · Score: 1

They've had a btrfsck for a long time, it's just not actually capable of detecting or fixing most forms of filesystem corruption yet. (I believe the original version literally did nothing.)
Re:Cool. by bingoUV · 2011-06-09 20:01 · Score: 1

That's Fedora for you. Or rather, I should say, Fedora is not for you, given your expectations from "production" ready.
"Reasonably" safe cutting edge features have always been part of Fedora - be it kernel level mode setting, pulse audio, ext4 in its early days. You are encouraged to file bugs if it makes your system crash. No guarantees that the bug will be fixed, of course.

--
Bingo Dictionary - Pragmatist, n. A myopic idealist.
Re:Cool. by JasterBobaMereel · 2011-06-09 20:21 · Score: 1

I must be doing something right ... I have never had to do a forced reboot of my main home system, or had to fsck a disk ... ...The only time I have had to do either was with a test install of FreeBSD some years ago, put me off it, and I went back to Linux ...(I have tried it since and it seems much more friendly, but I still prefer some of the Linux Distros)

--
Puteulanus fenestra mortis
Re:Cool. by jetole · 2011-06-09 22:17 · Score: 1

No you are doing something very wrong. All distros I know of check the disk via fsck every so often. Typically if it has been more then 45 days since the last fsck run then a check is done at boot time.
Re:Cool. by petteyg359 · 2011-06-10 01:00 · Score: 1

for x in $(ls /dev/sd*); do tune2fs -c0 -i0 ${x}; done
Re:Cool. by Anonymous Coward · 2011-06-11 03:04 · Score: 0

And KDE4, and GNOME 3...
Fedora is full of duds. It has so much potential, but it's far too experimental, to the point where I don't even know why they make "releases". It's basically in permanent, constantly (and drastically) changing beta. Or even seemingly alpha, at times.
It's sad because you're stuck with either have the alpha/beta-quality constantly changing testbed known as Fedora and its "spins", and on the complete opposite side you have stable, long-supported, but often relatively out-of-date Red Hat/CentOS/Scientific Linux. There is no middle ground.
It looks like with Ubuntu's last several versions and the future of the distribution, Fedora doesn't have to feel so bad... because Ubuntu is becoming just as experimental, alpha/beta quality, fast-moving and controversial. At least in the case of Ubuntu... there's always Debian (stable and, for more up-to-date packages, testing).

Dual boot? by Anonymous Coward · 2011-06-09 02:10 · Score: 0

So how will this affect the dual boot folks who use a partition for multiple OS'es?

Re:Dual boot? by Anonymous Coward · 2011-06-09 02:13 · Score: 0

Just because a filesystem defaults to one thing doesn't mean that it won't accept another FS type.
Re:Dual boot? by Anonymous Coward · 2011-06-09 02:32 · Score: 0

So how will this affect the dual boot folks who use a partition for multiple OS'es?
If they use an OS that can't read btrfs they won't be able to read btrfs..
Re:Dual boot? by Anonymous Coward · 2011-06-09 05:21 · Score: 0

It'll affect those folks by making them want their other OSes to work with more filesystems. Or it'll affect them by making them resent continued filesystem development since they can't ever personally benefit from technological advances, eventually turning them into luddites.

Btrfs features forced on users? by Denogh · 2011-06-09 02:10 · Score: 1

Pretty sure default filesystem != mandatory. They're not going to suddenly drop support for ext*.

Re:Btrfs features forced on users? by Denogh · 2011-06-09 02:11 · Score: 3, Informative

Oh wait... I'm a dummy that can't read.
Re:Btrfs features forced on users? by arth1 · 2011-06-09 02:39 · Score: 5, Informative

Pretty sure default filesystem != mandatory. They're not going to suddenly drop support for ext*.
No, but you may have to know how to get it.
If you install from a LiveCD, which is the default method of install, and the only one you'll see unless you dive deep down on the Fedora site, you have to use the file system they give you. You can change partitioning and much else, but not the file system type. If you do, the installation will fail, telling you that you have to use the same file system as the CD image.
To get an image that lets you choose the file system without erroring out if you do, you have to (at present):
- Instead of "Download Now", click "More option"
- Instead of one of the many options listed there, click "All download methods" hidden on the bottom right.
- Choose one of the packages under "Install Media" section.
If you don't, you can, at present, choose any file system you want, as long as it's ext4. Presumably, with F16, it will be btrfs.
This jumping through hoops seems to be deliberate by Fedora to get people to not use the full install DVDs, but install through a LiveCD instead.
As I need extended metadata support for Samba to support full CIFS compatibility including advanced permissions, there's really only one performance file system to choose: xfs
Btrfs won't be touching my machines until it's forked away from Oracle.
Re:Btrfs features forced on users? by Anonymous Coward · 2011-06-09 02:46 · Score: 0

Fedora is a bleeding edge distribution. Noone said you can't use ext*, just that btrfs is going to be the *default*. If you don't like it, change it, or simply don't use a bleeding edge distribution.
Re:Btrfs features forced on users? by Denogh · 2011-06-09 03:07 · Score: 1

You are correct in all of that.

I've been installing my Fedora KDE spin from live disks since early in 13. I expect this is going to be an inconvenience for future installs, but hardly insurmountable. Finding the install image instead of the live image will be the worst part.

Of course, this won't be a problem for current installs, as I'm certain `preupgrade` won't be reformatting anything.
Re:Btrfs features forced on users? by drunkahol · 2011-06-09 03:26 · Score: 1

Conversion to btrfs, however, isn't out of the question. It is unlikely that this would be forced on you during pre-upgrade though.
Re:Btrfs features forced on users? by Anonymous Coward · 2011-06-09 03:51 · Score: 0

If you install from a LiveCD, which is the default method of install, and the only one you'll see unless you dive deep down on the Fedora site, you have to use the file system they give you. You can change partitioning and much else, but not the file system type.
Really not trying to come off as an arse, but is Fedora really that shoddy? The Ubuntu live cd installer defaults to EXT4, but a whole slew of other filesystems are about three clicks away and the choices range from archaic to esoteric to bleeding edge.
Re:Btrfs features forced on users? by Bob+Loblaw · 2011-06-09 04:03 · Score: 1

On top of that, I am quite certain that this isn't going to affect upgrades at all.
The partition layout/filesystem types that you had before are going to be the ones you have after just like the vast majority of upgrades before now.
So no one's existing files are going to be affected.
Re:Btrfs features forced on users? by MikeUW · 2011-06-09 04:30 · Score: 1

If I recall correctly (haven't installed Fedora from scratch since about version 11), you can pick your filesystem using the advanced options in the installer, just like the Ubuntu installer. I don't recall whether this option is left out of the LiveCD installer, but I doubt it. As far as I understand, the LiveCD just has less packages installed by default...but the installer it runs is otherwise the same.
Re:Btrfs features forced on users? by S.O.B. · 2011-06-09 05:10 · Score: 1

I would have thought the same thing but I just checked the F15 LiveCD in VMWare using the default partition layout and although you can change the filesystem for the /home mount point it complains about the /boot and / mount points. It states /boot must be on ext4 and that / must be the same as the LiveCD (which does happen to be ext4).
So I would assume unless they make some changes to the installer for F16 or the LiveCD is offered in an ext4 and btrfs flavours then anyone wanting to override the default choice of btrfs will have to use an alternate install method.

--
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Re:Btrfs features forced on users? by Riceballsan · 2011-06-09 05:40 · Score: 1

Well I do agree, it's kinda crazy and stupid, though I do have to say, the people that need a dual boot system of multiple linux flavors, probably wouldn't have a hard time accessing this, and secondly even in a dual boot setup for a linux box I'm pretty sure you usually aren't reformatting the whole drive, at the most you are formatting your /. most any use for a dual boot linux system that I can think of would have /home and well whatever other paths you have... set to not format during the install. Not comfortable enough in linux to manage multiple partitions.... well you probably aren't going to be installing 10 flavors of linux on a system then, at most you should be using a VM if you are just trying them all out.
Re:Btrfs features forced on users? by arth1 · 2011-06-09 06:14 · Score: 1

It isn't a problem only for dual boot. It's a problem if you install Fedora as the only OS on a blank drive too.
If you use the CD they recommend to "get Fedora" (or even another one from "Additional options") you get no choice in file systems.
Only if you know about the difference, and hunt down the Install CD (or DVD) under "All download methods" can you get a choice of filesystems.
Re:Btrfs features forced on users? by m50d · 2011-06-09 09:29 · Score: 2

Just OOI, what's wrong with reiserfs or JFS?
/currently running FreeBSD for the sake of ZFS, because it's the only way to not lose data when hard disks die.

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I am trolling
Re:Btrfs features forced on users? by arth1 · 2011-06-09 10:03 · Score: 1

ReiserFS 3 doesn't support many of the functions modern file systems need, and Reiser4 was never finished before you-know-what.
JFS is a good solid file system; and probably what I would use if I didn't use xfs. When I tried it, it performed admirably -- it only lacks a dump/restore program that handles all the file system metadata like xfsdump/xfsrestore does for xfs.
Re:Btrfs features forced on users? by silanea · 2011-06-09 10:19 · Score: 1

I remember reading something about btrfs support for /boot coming only in recent kernels. Ubuntu 10.10 does not have this option, and I am not sure 11.04 has it, but it definitely should be in 11.10, so I assume it requires (or coincides with? Not sure which part exactly is to blame, the kernel module or the boot loaders.) kernel versions >2.6.35. So F16 may well offer both options from a single live-cd.

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Rudolf Hess edited Mein Kampf. He was the very first grammar nazi.
Re:Btrfs features forced on users? by bingoUV · 2011-06-09 20:21 · Score: 2

FYI, Fedora doesn't support jfs. First, you have to pass a kernel argument "jfs" to make fedora even run a JFS / or /boot. Even then, jfs is not presented as option for /, /home or any other mount point.
I've been using jfs on Fedora by
1. installing with ext4
2. boot into it
3. install jfsutils
4. backup the files
5. create a jfs file system
6. copy files on jfs file system
7. edit grub.conf and add jfs kernel argument.
jfs bugs are rejected by bugzilla.

--
Bingo Dictionary - Pragmatist, n. A myopic idealist.

But... btrfs isn't stable by Anonymous Coward · 2011-06-09 02:10 · Score: 0

This doesn't make sense.

Re:But... btrfs isn't stable by MrHanky · 2011-06-09 02:25 · Score: 4, Insightful

It makes perfect sense. Btrfs won't get stable for RHEL unless it's beta tested in Fedora first.
Re:But... btrfs isn't stable by mcavic · 2011-06-09 02:43 · Score: 0

Fedora isn't stable. It might work perfectly well, but the updates are too fast and many to be considered stable.
Re:But... btrfs isn't stable by Nimey · 2011-06-09 03:24 · Score: 1

Nobody said Fedora was stable.

--
Hail Eris, full of mischief...

E pluribus sanguinem
Re:But... btrfs isn't stable by TheRaven64 · 2011-06-09 04:38 · Score: 1

That's the point. Red Hat enables it in Fedora and, when they stop getting bug reports, they enable it in RHEL.

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Re:But... btrfs isn't stable by mcavic · 2011-06-09 19:21 · Score: 1

I know, I just meant that if Fedora isn't considered stable, of course btrfs shouldn't be considered stable.
Re:But... btrfs isn't stable by Nimey · 2011-06-10 02:07 · Score: 1

That doesn't follow. Ubuntu 11.04 isn't "stable", as such, but it ships with Firefox 4, which is considered stable.

--
Hail Eris, full of mischief...

E pluribus sanguinem
Re:But... btrfs isn't stable by mcavic · 2011-06-10 13:19 · Score: 1

I see your point, but a filesystem is a kernel feature, and much more integral to the OS than a browser.

Is the disk format fixed? by Anonymous Coward · 2011-06-09 02:11 · Score: 0

So.. Is the format of btrfs fixed now? Because last time I looked at the kernel it had a great big warning about possible future changes.

Re:Is the disk format fixed? by Carewolf · 2011-06-09 02:37 · Score: 2

Yes, it was officially fixed in 2.6.32 or something like that. They keep adding more features and improving it, but the format is supposed to be fixed by now.
Anyway. I don't know if default is a good idea, but even Debian offered btrfs as an option when I installed it on my new laptop last month. It is hardly cutting edge anymore ;)

Fedora is essentially RHEL beta by Anonymous Coward · 2011-06-09 02:12 · Score: 1

This means that all the good things with BTRFS could be stable enough for servers within a year or so. Hopefully, this means that Linux admins won't have to spend much more time longingly lusting after ZFS.

Re:Fedora is essentially RHEL beta by mcavic · 2011-06-09 02:46 · Score: 1

Well, give them 2 years. As far as I know, RHEL still doesn't have TRIM support.
Re:Fedora is essentially RHEL beta by idontgno · 2011-06-09 03:26 · Score: 1

RHEL 6, ext4 only, enabled by mount option:

mount -t ext4 -o discard <device> <mountpoint>

linky

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Re:Fedora is essentially RHEL beta by mlts · 2011-06-09 05:34 · Score: 4, Informative

ZFS still has a lot btrfs doesn't:
64 bit CRC support so disk corruption is caught.
RAID 5/6
Block level deduplication
Encryption
ZFS also replaces the LVM layer, making write performance on raid-Z a lot better than a filesystem + LVM layer.
This isn't to say btrfs is bad, but until dedupe is added, it will be a generation behind the competition.
Re:Fedora is essentially RHEL beta by toby · 2011-06-09 07:37 · Score: 2

"64 bit CRC"? No. ZFS uses 256 bit checksums for each block.
Also, ZFS does not implement RAID-5, RAID-6 or any of the conventional RAID modes; but it has "RAID-like" modes (e.g. mirrored vdev, RAID-Z, RAID-Z2).

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you had me at #!
Re:Fedora is essentially RHEL beta by mlts · 2011-06-09 08:14 · Score: 3, Interesting

Thanks for the correction, as that definitely is a notable difference.
Now, if we can get a filesystem that supports autotiering (where it knows which array is SSD, which is spindles and places data accordingly due to times accessed), that would be great. Outside of EMC's offerings, I don't know any really available.
Re:Fedora is essentially RHEL beta by bingoUV · 2011-06-09 20:30 · Score: 1

Well, RAID-Z can almost emulate RAID-5 and RAID-6.
Also, BTRFS does have RAID and LVM capabilities as mentioned in the summary. It can also span multiple storage devices.

--
Bingo Dictionary - Pragmatist, n. A myopic idealist.

Rollback system changes by EponymousCustard · 2011-06-09 02:14 · Score: 2

Does this mean we are a step closer to the possibility of snapshotting system states and rolling back to before a bunch of updates were installed?

Re:Rollback system changes by Anonymous Coward · 2011-06-09 02:22 · Score: 0

Sure. The solution is to install Windows.
Re:Rollback system changes by somersault · 2011-06-09 02:26 · Score: 0

Don't see why the file system would really make a difference for that.
You could also have a look at these new fangled "backup" thingies. Keep your user data in a separate partition for example, and you can backup/restore the system separately. You'd probably also want to backup/restore in that situation too ~/.* of course.

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which is totally what she said
Re:Rollback system changes by Anonymous Coward · 2011-06-09 02:31 · Score: 0

I don't think he was asking how to degrade his system.
Re:Rollback system changes by rwa2 · 2011-06-09 02:32 · Score: 2

Sure, you can sort of do that with LVM now.
What doesn't work with LVM, unfortunately, is using snapshots that allow you to "roll forward" if the system updates work out all right and you want to accept the updates into your main volume :-/
Re:Rollback system changes by Anonymous Coward · 2011-06-09 02:39 · Score: 1

If the file system supported snapshots and copy-on-write it would really make a difference.
Re:Rollback system changes by Znork · 2011-06-09 02:40 · Score: 1

The LVM merge feature has been available for around a year now, at least it's available in F14. Or are there some issues with it that make it unsuitable for doing that?
Re:Rollback system changes by BrentH · 2011-06-09 02:42 · Score: 4, Informative

The fact that you don't see how a filesystem integrated snapshot function could make a difference tells me that you've never used anything like that. And your alternative of managing partitions and 'backups' tell me that you certainly have never tried to manage anything like this on a scale beyond your own machines.
Let me tell you, ZFS-like snapshots are the best improvement to computing since proper multi-user systems. It makes managing file security and integrity so, so much easier, and at almost no cost. (and by ZFS-like I mean with the ease and speed of ZFS, I've not yet seen much numbers on BTRFS performance)
Re:Rollback system changes by EponymousCustard · 2011-06-09 02:42 · Score: 4, Interesting

Snapshot takes minimal disk space compared to a backup. Plus you would need to backup the entire / tree to rollback changes made by a yum update.
Re:Rollback system changes by Anonymous Coward · 2011-06-09 02:43 · Score: 0

I don't think he was asking how to degrade his system.
No, he was asking how he could roll back to a known state before the latest patches were installed. The solution that the other Anonymous Coward proposed - to install Windows - is certainly valid as it has been able to do this for many years.
Re:Rollback system changes by somersault · 2011-06-09 02:56 · Score: 1, Insightful

Snapshot takes minimal disk space compared to a backup
Use an incremental backup?
I'm not saying it wouldn't be a nice feature to have built into the OS, just that instead of hoping for such a feature in future, people can have similar functionality right now if they really want it.

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which is totally what she said
Re:Rollback system changes by Anonymous Coward · 2011-06-09 03:02 · Score: 0

Sure. The solution is to install Windows.
Lol. He didn't want to roll back from broken to even more broken.
Re:Rollback system changes by ToasterMonkey · 2011-06-09 03:03 · Score: 1

Sure, you can sort of do that with LVM now.
What doesn't work with LVM, unfortunately, is using snapshots that allow you to "roll forward" if the system updates work out all right and you want to accept the updates into your main volume :-/
I bet you couldn't find five sysadmins in the (one one) country who do this in production.
Brtf alone isn't going to bring to Linux:
create new boot environment 'foo'
mount 'foo' to /mnt
install patches/updates/new software to root at /mnt
umount 'foo'
activate 'foo'
reboot
Then from the boot menu, pick 'previous_foo' if 'foo' is broken.
That's a lot of really different projects that would have to come together for Linux to pull it off, one being dramatically different distro to distro. We've already heard folks shout "layering violation" at basic parts of ZFS itself, what hope does all this have?
Re:Rollback system changes by Anonymous Coward · 2011-06-09 03:13 · Score: 0

...or defile his system.
Re:Rollback system changes by Rich0 · 2011-06-09 03:27 · Score: 2

I believe in btrfs that a snapshot is itself a mountable structure, so in theory all you have to do is do a snapshot called "previous_foo" and then install your changes, and if it doesn't work boot with (real_)root= on your kernel line.
Not a whole lot needs to actually come together unless you want it all automated. Then again, I run gentoo so my grub.conf is hand-configured anyway. :)
Re:Rollback system changes by Hylandr · 2011-06-09 03:30 · Score: 1

Re-installing windows is hardly what I would call a viable roll back...
- Dan.

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~ People that think they are better than anyone else for any reason are the cause of all the strife in the world.
Re:Rollback system changes by Bob+Loblaw · 2011-06-09 03:46 · Score: 3, Insightful

There was already a yum plugin for this (yum-plugin-fs-shapshot) as far back as F13 as mentioned here: http://fedoraproject.org/wiki/Btrfs_in_Fedora_13
It will do an automatic btrfs snapshot of affected filesystems before every yum transaction so that you can go back to whatever point you want. Also, since it is partition dependent, you can rollback your system partition and not undo changes you may have made to your home directories if you have those on different partitions.
btrfs is quite powerful but I have found that the user/GUI tools have not come up to speed yet. I have been using btrfs from my F15 netbook and it seems to have caused no issues so far. However, enabling transparent compression and any tweaking has entailed editing /etc/fstab (never a thing to do lightly) and command lines.
Hopefully some of the GUI disk management tools will start to make available some of the capabilities of btrfs.
Re:Rollback system changes by grumbel · 2011-06-09 04:00 · Score: 4, Interesting

Use an incremental backup?
That would still mean a shitload of data to copy around. The point of copy-on-write snapshots is that the cost of copying your whole file system is essentially zero.
To make an normal application analogy: Of course you don't really need Undo/Redo, you can just "Save As" your file at any step of the way, but Undo/Redo makes things a hell of a lot more convenient and more importantly it helps you in those situation where you would have considered a "Save As" to be to much work to bother with and thus have no backup to fall back to.
Re:Rollback system changes by somersault · 2011-06-09 04:20 · Score: 1

It's definitely convenient if you want to be able to do this kind of thing very often, and for something that you just did say 10 minutes ago. But for example the Volume Shadow Copy functionality we have on our Windows file server just runs incremental snapshots every night, which doesn't get in anyone's way, and avoids the performance hit of writing everything twice every time you save (which admittedly won't be a big deal in most cases).

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which is totally what she said
Re:Rollback system changes by TheRaven64 · 2011-06-09 04:47 · Score: 2

Nexenta does this already. They have an apt-clone utility that wraps apt-get and ZFS snapshots. It takes a snapshot, then does the upgrade. If you don't like it (e.g. stuff breaks), you roll back to the snapshot. If you do, then you just delete the snapshot and continue.

We've already heard folks shout "layering violation" at basic parts of ZFS itself
And the person who said this clarified it saying that it wasn't a criticism. It's also wrong. ZFS has very clean layering, it just doesn't put the layers in the same place as System V.

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I am TheRaven on Soylent News
Re:Rollback system changes by doublebackslash · 2011-06-09 05:00 · Score: 1

In apt systems at least...
Create an overlay filesystem based on /
chroot into the overlay
run updates
have a handy dandy "boot into overlay" option (I've done this, knoppix does this, it isn't hard and they CAN put it in there with no hassle)
test
test more
give it the okay!
reboot into a "collapse the changes into the mainline root" mode which will then reboot normally (into the freshly collapsed root). One can collapse the two using rsync. It will be very fast
Profit.
Take you two hours to do or about three weeks if you wanted it to be useful for the unwashed masses. Nobody does this because.... ummm... Actually I'm not sure, but I'll bet it has a lot to do with POTENTIALLY breaking things and you can't put that into a distro.
However, feel free to whip it up and enjoy. I just take a nice sturdy backup before a major change. If you think that restoring a backup is too long / costly / unreliable then you have a problem with you backup system. Also: test environments are handy. I guess those are good arguments against having a built-in "try and see" mode. Breaks things and there are better solutions than mucking about with your boot config and filesystems for most.
I guess I don't have a point... Enjoy either way!

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md5sum /boot/vmlinuz
d41d8cd98f00b204e9800998ecf8427e /boot/vmlinuz
Re:Rollback system changes by Ossifer · 2011-06-09 05:02 · Score: 1

Never worked for me...
Re:Rollback system changes by grumbel · 2011-06-09 05:55 · Score: 1

and avoids the performance hit of writing everything twice every time you save (which admittedly won't be a big deal in most cases).
I think you misunderstand copy-on-write. Copy-on-write doesn't write stuff twice, the point of it is that it writes almost nothing at all. If I have a file Foobar1 and copy it to Foobar2 both of them will point to the same data on the drive. The file will not be copied, but instead the filesystem will simply recorded that Foobar2 is a copy of Foobar1. However when I change blocks in Foobar2, the changes will be written to new blocks and not change blocks of Foobar1.
It is essentially the same what Volume Shadow Copy does, just a more powerful generalized way of doing it.
Re:Rollback system changes by Anonymous Coward · 2011-06-09 06:02 · Score: 0

>editing /etc/fstab (never a thing to do lightly)
Well, maybe not... you can always save a backup first and restore it easily enough.
If you don't understand how to do that, then yes, don't touch fstab. ever.
Re:Rollback system changes by somersault · 2011-06-09 06:08 · Score: 1

Okay. That's pretty damn cool :)

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which is totally what she said
Re:Rollback system changes by rwa2 · 2011-06-09 07:29 · Score: 1

Hmm, I don't know, I just remember reading about merging being problematic when I was trying to do that some time ago. Of course I'm just using CentOS for work most of the time, so it'll be even longer before I see it.
http://www.jonnor.com/2010/02/lvm-snapshot-merging-avaliable/
Re:Rollback system changes by cthulhu11 · 2011-06-09 16:01 · Score: 1

Why on earth is a graphical interface needed for btrfs? I've never once yearned for a bloated, high-bandwidth alternative to "zpool create".

still not using grub2? by drinkypoo · 2011-06-09 02:14 · Score: 3, Interesting

Summary: We like it when you test new stuff for us, and our customers are clamoring for this filesystem in RHEL, so we're going to let you try it out on Fedora for a while and experience the hiccoughs. And speaking of new stuff, we're going to finally get around to moving up to grub2 like everyone else, which we haven't bothered to implement even though it's much better, and we allegedly like new stuff.

--
"You're right," Fisheye says. "I should have set it on 'whip' or 'chop.'"

Re:still not using grub2? by BreezeC · 2011-06-09 02:18 · Score: 2

Maybe the boss redhat don't like grub2.
Re:still not using grub2? by grasshoppa · 2011-06-09 02:24 · Score: 2, Informative

Yes, and? I thought it was well known that fedora is the test bed for RHEL.

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Mod me down with all of your hatred and your journey towards the dark side will be complete!
Re:still not using grub2? by drinkypoo · 2011-06-09 02:32 · Score: 2

Yes, and therefore "When it comes to adopting the newest technologies, Fedora is always at the front among the major Linux distributions" is a dirty lie. It should be "When it comes to convincing fools to beta-test RHEL for us, Fedora is the shiznit!" What does "major Linux distributions" mean, anyway? I'd give that to Gentoo, which often makes functionality available very early.
Fedora is of course at the forefront of adopting the newest technologies developed by Red Hat. Some of what they have written has been very nice. I don't want to take anything away from them. I only find this blog entry to be an inane piece of marketfluff.

--
"You're right," Fisheye says. "I should have set it on 'whip' or 'chop.'"
Re:still not using grub2? by Rich0 · 2011-06-09 03:33 · Score: 4, Informative

So, I'm a Gentoo Dev and I'd qualify that statement a little. Gentoo tends to make a lot of stuff available very early, but it doesn't tend to go all-in with experimental stuff for the base user experience. The default Gentoo stable experience is legacy Grub, for example. And Gentoo hasn't bought into Unity/Systemd/etc. Although, there is talk of adding systemd to the list, and Chrome OS is a Gentoo-based distro that uses unity - so clearly it can be done.
Gentoo tends to be about giving users a default experience that is reasonably stable, but making it a lot easier for users to branch out and try different things, while still keeping much of the update automation in place.
Gentoo tends to be less about the polished desktop experience, so I suspect we'll always lag something like Ubuntu in that regard - at least when it comes to ripping apart everything and trying something new.
Re:still not using grub2? by drinkypoo · 2011-06-09 04:43 · Score: 1

When I was running Gentoo it was trivially easy to jump on the bleeding edge. Is that no longer true? That was my second-favorite thing about it (number one being that I actually ended up with a build for the K6 I was using it on.)

--
"You're right," Fisheye says. "I should have set it on 'whip' or 'chop.'"
Re:still not using grub2? by zixxt · 2011-06-09 06:40 · Score: 1

Grub2 seems to be very not well liked by a number of users and distros.

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---- GENERATION 26: The first time you see this, copy it into your sig on any forum and add 1 to the generation.
Re:still not using grub2? by Anonymous Coward · 2011-06-09 06:52 · Score: 0

we're going to finally get around to moving up to grub2 like everyone else, which we haven't bothered to implement even though it's much better
How is it "much better"? Needlessly changing device designations and wrapping, what was once a simple, elegant, and effective bootloader, with layer upon layer of boilerplate shell scripting, is "much better"? Creating a directory of shell scripts that literally do NOTHING but print configuration directives is "much better"?
I'm glad they've stuck with grub1 and wish they'd continue to do it.
Re:still not using grub2? by drinkypoo · 2011-06-09 06:53 · Score: 1

people get grumpy when they have to learn something new but grub2 is definitely a step forward. As an Ubuntu user I don't even have to care. As a nerd I have tinkered with it and I don't get why people are whinging.

--
"You're right," Fisheye says. "I should have set it on 'whip' or 'chop.'"
Re:still not using grub2? by m50d · 2011-06-09 09:25 · Score: 1

It is easy to jump on the bleeding edge. It's just worth emphasising that gentoo won't put you there by default, as many of its critics seem to think.

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I am trolling
Re:still not using grub2? by Rich0 · 2011-06-09 13:14 · Score: 2

It is, but keep in mind that there are many bleeding edges.
You could be running bleeding edge postfix, or you could be running bleeding edge sendmail - the distro doesn't care which.
You could be running bleeding edge KDE or Gnome - again we don't care.
You could be running the default openrc, or perhaps one day you could be running systemd (right now we care - some would like to change that).
There is a default experience if you follow the guidebook and don't mess with certain flags/packages/etc. It can be stable or bleeding-edge. However, to do the really exotic stuff you need to go looking.
The typical experimental user tends to stick with fairly stable stuff for 95% of the system, and go crazy with the other 5%. That lets them do something exotic without having to play whack-a-mole with all the bugs.
Re:still not using grub2? by Anonymous Coward · 2011-06-09 21:58 · Score: 0

and Chrome OS is a Gentoo-based distro that uses unity
Bullshit. Chrome OS is based on Ubuntu. Get your facts straight.
Re:still not using grub2? by Anonymous Coward · 2011-06-09 22:33 · Score: 0

Chrome OS does not use Unity. Do you have any knowledge or are you just babbling?
Re:still not using grub2? by Rich0 · 2011-06-10 09:54 · Score: 1

Hmm, thought I had read that it did. Seems that you're only half-wrong, or were you just trolling? :)
Re:still not using grub2? by Rich0 · 2011-06-10 09:55 · Score: 1

How about getting your FAQs straight?
Re:still not using grub2? by profplump · 2011-06-14 15:37 · Score: 1

I've yet to figure out what advantage it provides over grub-legacy, other than it compiles for x86_64. Sure, it's got more functionality but it's also harder to build, harder to install/configure, and in the typical use case it does literally nothing different. You could make the same argument for lilo over grub, and people did for a long time -- unless you actually want one of the new features it's a much more complicated system that gets you nothing useful. I personally liked the ability to switch kernels/etc. at boot time and made an early switch the grub, but I can absolutely see why the average user though lilo was good enough, and was willing to deal with floppy-rescue on the rare occasion that they forgot to update their kernel pointer.
Frankly the real problem is people still put up with crappy BIOS-based pre-boot environments. Most of the stuff grub2 tries to do should happen in the firmware, and on systems with OpenFirmware/decent UEFI implementations/etc. it does. Give the firmware support for a couple of common file systems and/or enough internal storage to stash the kernel internally, and just forget the whole on-disk bootloader. Add a standard programming language to that (as both UEFI and OpenFirmware did) and you can write arbitrary extensions for pre-boot functionality, to add functionality to older hardware without updating the underlying firmware.
Re:still not using grub2? by drinkypoo · 2011-06-15 02:43 · Score: 1

Frankly the real problem is people still put up with crappy BIOS-based pre-boot environments. Most of the stuff grub2 tries to do should happen in the firmware, and on systems with OpenFirmware/decent UEFI implementations/etc. it does.
Great, out of ten or so PCs around here maybe two of them even try to have an improved BIOS, and only one has working UEFI AFAIK. OTOH... :) Seriously though, the reality is that there are many PCs with crappy BIOS out there and most of them can't be upgraded with Coreboot. If they could, the payload you'd want would likely be GRUB anyway.

--
"You're right," Fisheye says. "I should have set it on 'whip' or 'chop.'"

mdadm woes begone? by Hylandr · 2011-06-09 02:14 · Score: 2

I was handed a block of drives that had been in a server recently with software raid and asked to rebuild the array and recover the data. This had been assembled with mdadm. Will this change make such recovery a non issue with snapshots and the like, providing of course the array had been running btrfs?

- Dan.

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~ People that think they are better than anyone else for any reason are the cause of all the strife in the world.

Re:mdadm woes begone? by guruevi · 2011-06-09 02:56 · Score: 4, Informative

Much like ZFS, mdadm will simply be replaced with another set of commands. If a drive crashes and the array is not correctly set up, you will also lose data and it will be a pain in the butt to repair it (I've done ZFS recovery of a corrupted pool, no fun). Again, RAID (or any software checksum based alternative) is not a backup. You should have hourly/daily/weekly snapshots and backups depending on the importance of your data.
The good thing about ZFS and Btrfs vs RAID is that they fail graciously. Most of the time it will be able to indicate which files are corrupt, allow you to mount read only and at least copy portions of it over so there is some more intelligence built-in than a simple XOR but that's just the progression of technology.

--
Custom electronics and digital signage for your business: www.evcircuits.com
Re:mdadm woes begone? by Rich0 · 2011-06-09 03:42 · Score: 3, Interesting

I think the bigger issue with btrfs vs mdadm and ext4 will just be maturity. Btrfs repair tools just haven't evolved to the same place the other tools are at, but there is no fundamental reason why they won't eventually make it there.
As you say btrfs has the advantage that it knows something about how the space is used, so if space was just free it could just nuke it and not worry about trying to salvage garbage data. It could also use free space to leverage recovery. And, the concept of COW means that strips are less likely to be in a transitory state of having meaningful data partially overwritten by other meaningful data, since the filesystem would first try to write the stripe over unused space leaving a fully intact backup if it is interrupted and the array is already degraded/etc.
The last time I tried test-converting an existing ext4 into a btrfs on RAID it paniced, but it has been almost a year now...
Re:mdadm woes begone? by Mysticalfruit · 2011-06-09 07:28 · Score: 1

Actually btrfs merely uses lvm and md devices on the underside. You can still run the lvscan / lvdisplay / mdadm, however what you'll see will look rather obtuse.

--
Yes Francis, the world has gone crazy.

Sources for this? by Dan+Dankleton · 2011-06-09 02:15 · Score: 5, Informative

Surely there could be a better source for this than one blog post (I know, high UID so I must be new here.)

But linking to something like http://fedoraproject.org/wiki/Features/F16BtrfsDefaultFs or http://thread.gmane.org/gmane.linux.redhat.fedora.devel/149196/focus%3D149215 to lend a little authority might have been nice...

Re:Sources for this? by Lunix+Nutcase · 2011-06-09 02:21 · Score: 3, Insightful

But how does that drive ad clicks for digitizor if one links to the official source? Silly you.
Re:Sources for this? by _Sprocket_ · 2011-06-09 02:44 · Score: 1

Your links are nice background / support. But they're hardly read as well. Sure - one can hash out the details via the wiki link. But I could see those details being missed without the narrative. So in this case, I would say the blog entry added something to the story unlike some blog entries we see that are simply re-hashing other blogs without adding anything themselves. If I had written the submission, I would have picked the blog entry as the primary link with your wiki link as supporting. If I had to pick one, I'd go with the blog entry. YMMV.

in other news ... by Anonymous Coward · 2011-06-09 02:15 · Score: 1

the Guinness World of Records has awarded the Shortest Living Filesystem Record to ext4

Re:in other news ... by somersault · 2011-06-09 02:29 · Score: 1

Reiser strikes again?

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which is totally what she said
Re:in other news ... by Anonymous Coward · 2011-06-09 02:34 · Score: 0

too soon.
Re:in other news ... by somersault · 2011-06-09 02:41 · Score: 1

Damnit! I wasn't sure, so I just went for it. Best policy :p

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which is totally what she said
Re:in other news ... by Jello+B. · 2011-06-09 02:50 · Score: 1

if a joke is funny it's never too soon.

I wonder if they have a working fsck yet? by Thrakkerzog · 2011-06-09 02:19 · Score: 3, Insightful

In the long run btrfs will be good to have, especially with solid state drives gaining popularity. Even embedded devices can easily have multi-gigabyte flash chips, and btrfs would be faster and more efficient on these when compared to jffs2 and yaffs.

Re:I wonder if they have a working fsck yet? by Zoidmann · 2011-06-09 02:26 · Score: 4, Informative

It seems like they haven't: https://btrfs.wiki.kernel.org/index.php/FAQ#When_will_Btrfs_have_a_fsck_like_tool

Hopefully they know something about it being released soon since making the decision to use it.
Re:I wonder if they have a working fsck yet? by cronius · 2011-06-09 02:30 · Score: 1

Regarding fsck, from: https://fedoraproject.org/wiki/Talk:Features/F16BtrfsDefaultFs#Recovery_strategy

fsck must work. It should be tested for a longer period to see if it's really working.
Would be nice if this speeds up the work on btrfs.fsck.

--
Life is Reality
Re:I wonder if they have a working fsck yet? by arth1 · 2011-06-09 02:43 · Score: 1

No plans for an fsr either.
So far, you need to stay at ext2/3 or xfs if you want defragmentation.
Re:I wonder if they have a working fsck yet? by Just+Some+Guy · 2011-06-09 03:17 · Score: 2

Is there a need an fsck? For example, ZFS doesn't have one and I haven't heard of anybody working on it (or of anybody actually wanting one).

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Dewey, what part of this looks like authorities should be involved?
Re:I wonder if they have a working fsck yet? by cratermoon · 2011-06-09 03:22 · Score: 5, Informative

It says right here on the btrfs wiki: "While Btrfs is stable on a stable machine, it is currently possible to corrupt a filesystem irrecoverably if your machine crashes or loses power on disks that don't handle flush requests correctly. This will be fixed when the fsck tool is ready. "
So I'd say yah, that's a pretty important piece to be missing if you're talking about making it the default for a distro, even one as free-wheeling as Fedor.
Re:I wonder if they have a working fsck yet? by Anonymous Coward · 2011-06-09 03:33 · Score: 1

Is there a need an fsck? For example, ZFS doesn't have one and I haven't heard of anybody working on it (or of anybody actually wanting one).
One could argue that the scrub function of the zpool command is comparable to an fsck.
--AC
Re:I wonder if they have a working fsck yet? by bill_mcgonigle · 2011-06-09 03:34 · Score: 5, Interesting

Is there a need an fsck? For example, ZFS doesn't have one and I haven't heard of anybody working on it (or of anybody actually wanting one).
Um, yeah, read zfs-discuss. There are helpful folks on there who help people recover their ZFS volumes, but having a tool to do it would be much better.
fsck for ZFS or btrfs means something different than it does for ext* but it's still needed. I just had a client's new 18TB ZFS zvol go TU when the power failed and the UPS->host communication wasn't properly connected. Fortunately it wasn't very important and the important zvol wasn't active when the power failed.
btrfs will be better than ZFS for many use cases once the fsck is stable. For others ZFS will remain better, but you better have battery-backed disk cache or a monitored UPS (neither of which are appropriate requirements for large swaths of the Fedora user base).

--
My God, it's Full of Source!
OUTSIDE_IP=$(dig +short my.ip @outsideip.net)
Re:I wonder if they have a working fsck yet? by Mullen · 2011-06-09 03:37 · Score: 3, Informative

I have seen this issue with other filesystems. It comes from when the hard drives *lie* to the RAID or I/O controller stating that they don't buffer or are not buffering when in reality, they are. It's really frustrating since you can't trust the drives have written out the data.

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Linux O Muerte!
Re:I wonder if they have a working fsck yet? by maskedbishounen · 2011-06-09 04:08 · Score: 3, Insightful

This. I run btrfs on my home file server and lost a half year of data due to a power outage corrupting the filesystem. Afterwards I was looking around for its fsck utility only to find it does not yet exist. Btrfs may be the way of the future, but as is, it's still too soon.

--
"An infinite number of monkeys typing into GNU emacs would never make a good program."
Re:I wonder if they have a working fsck yet? by Anonymous Coward · 2011-06-09 04:13 · Score: 0

So far, you need to stay at ext2/3 or xfs if you want defragmentation.
False. You obviously argue from ignorance, so I'd suggest you read up on how btrfs actually works. Look here for an example. Google will tell you even more.
Re:I wonder if they have a working fsck yet? by Anonymous Coward · 2011-06-09 04:24 · Score: 0

Can you test whether your drives behave properly?
Re:I wonder if they have a working fsck yet? by nairnr · 2011-06-09 04:27 · Score: 2

Well, ZFS has scrub which goes through and verifies all checksums, for mirror or raidz it repairs and discrepancies so it is fsck like.
Re:I wonder if they have a working fsck yet? by arth1 · 2011-06-09 05:03 · Score: 1

The "defragment" in btrfs isn't a defragmenter in the normal sense of the word (aside from being broken) -- you can only defragment individual files, not file systems.
It's also incompatible with copy-on-write, as it forces a copy to be made.
Unless the entire design changes, you might as well just use the workarounds you've used on ext4/reiser for a long time.
Re:I wonder if they have a working fsck yet? by nutznboltz · 2011-06-09 05:17 · Score: 1

It seems like they have: http://git.kernel.org/?p=linux/kernel/git/mason/btrfs-progs-unstable.git;a=blob;f=btrfsck.c;h=63e44d1dbc26f2ee9f6ef29c08ae0eb9d19e48db;hb=HEAD
Re:I wonder if they have a working fsck yet? by dzr0001 · 2011-06-09 06:20 · Score: 1

ZFS has its own problems with scrubbing. Ever have to replace a Zil? Enjoy scrubbing performance loss hell for days/weeks/months depending on the size of your pool.
Re:I wonder if they have a working fsck yet? by shentino · 2011-06-09 06:22 · Score: 1

Translation:
"We can get fucked over when a device lies to us about buffering just like any other filesystem, and it's not our fault if you have shitty hardware that doesn't follow instructions like it's supposed to."
Re:I wonder if they have a working fsck yet? by greed · 2011-06-09 06:39 · Score: 1

Not reliably; you'd need to issue a flush to the disk itself, then as soon as you get the "completed" response you'd have to drop power to the drive. You could build a test rig with a relay under control of the test program, I suppose, to interrupt the power to the disk.
Then, after powering the drive back up, you'd check for your known value. Repeat a whole bunch of times, because this is obviously a race condition; it would probably help to have an active "read" load at the same time.
Re:I wonder if they have a working fsck yet? by Anonymous Coward · 2011-06-09 06:54 · Score: 0

scrub will not help you if a crash caused key fs data structures to get corrupted on disk. The purpose if scrub is to find and correct bitrot, not to fix an inconsistent disk state. Btrfs will have both fsck and scrub tools, as they serve different purposes.
Re:I wonder if they have a working fsck yet? by intangible · 2011-06-09 08:04 · Score: 1

Maybe a startup test would work, but dunno how consistent that would be... if you tested more often, you'd impact performance badly.
Re:I wonder if they have a working fsck yet? by Chirs · 2011-06-09 11:21 · Score: 1

For others ZFS will remain better, but you better have battery-backed disk cache or a monitored UPS (neither of which are appropriate requirements for large swaths of the Fedora user base).
Actually, a large swath of the Fedora user base runs laptops, which depending on how you look at it could be considered either a battery-backed disk cache or a monitored UPS.
Re:I wonder if they have a working fsck yet? by bill_mcgonigle · 2011-06-09 14:12 · Score: 1

Actually, a large swath of the Fedora user base runs laptops, which depending on how you look at it could be considered either a battery-backed disk cache or a monitored UPS.
Ideally. I've had my Fedora run out of battery while shutting down (triggered by power management) often enough that I wouldn't trust it. I run my ext4 with data=journal.

--
My God, it's Full of Source!
OUTSIDE_IP=$(dig +short my.ip @outsideip.net)
Re:I wonder if they have a working fsck yet? by cratermoon · 2011-06-10 04:54 · Score: 1

While I agree with your position that the hardware is flawed and possibly defective by design, I disagree that this absolves the Fedora and btrfs developers from having to do anything.
The old saw "Be strict in what you send, but generous in what you accept" applies here. Because there *is* a way that the filesystem can recover -- though admittedly with some difficulty -- from a hardware fault like this. Other filesystems offer tools to deal with such hardware.
By making it the default fs, Fedora is putting the sysadmins in the difficult position of trying to determine if the hardware they have is flawed or choosing a different fs at install time anyway. Because it's virtually impossible to know if the hardware doesn't properly implement what the manufacturer claims it does, a prudent sysadmin MUST choose a different filesystem.
Granted, this is Fedora, the distribution aimed at folks who are maybe willing to be less prudent and accept some risk. Perhaps the leverage of Fedora users asking for it along with the large body of "in the wild" testing will give btrfs developers the kick needed to close this gap.
Re:I wonder if they have a working fsck yet? by cratermoon · 2011-06-10 05:21 · Score: 1

Yeah, when the hardware is defective by design, the filesystem does get screwed up. It's up to the fs developers to account for this and provide tools to recover. Failure to do so and instead blaming the hardware or the sysadmin for using flawed hardware is not an acceptable stance.

My experiences with btrfs by Gaygirlie · 2011-06-09 02:33 · Score: 3, Interesting

For some reason I'm getting really low performance on btrfs, both on a single disk and on raid1 configurations. I have tried with -nodatacow and with and without -compress, but it seems it doesn't have any effect. Also, I have 90 gigabytes of free space on Storage1 but I get drive full error when I try to write there. Rebalancing it didn't fix the issue. The btrfs command-line tool is, well, rather incomplete and somewhat buggy, like e.g. when I query 'btrfs fi df /media/Storage2' -- with Storage2 being the raid1 pool -- it reports the size and usage of the smallest disk on it, not the whole thing. I don't understand why. I also have had some filesystem corruption which caused me to lose quite a bit of data, and again the only way to fix it was rebalancing the whole thing which takes the whole damn day.

I do understand that it's a filesystem that's still under development, but the tools atleast need a lot more work. They're just too incomplete at the moment. I'm not really sure pushing it as the default filesystem for end-users is a good idea yet.

Re:My experiences with btrfs by arth1 · 2011-06-09 02:46 · Score: 3, Informative

. The btrfs command-line tool is, well, rather incomplete and somewhat buggy, like e.g. when I query 'btrfs fi df /media/Storage2' -- with Storage2 being the raid1 pool -- it reports the size and usage of the smallest disk on it, not the whole thing. I don't understand why.
With RAID 1 (simple mirroring), your volume is limited to the smallest of the components. A 40 GB and a 2 TB drive put together yields a 40 GB RAID 1 volume.
Re:My experiences with btrfs by Gaygirlie · 2011-06-09 02:57 · Score: 1

My mistake, I meant raid0, ie. with striping. The odd thing is that the tools report it as raid1. And yes, I have way more stuff there than the smallest drive, so it can't be raid1.
Re:My experiences with btrfs by Bengie · 2011-06-09 03:01 · Score: 1

I read one person's blog a few weeks back about how he had BTRFS set on attempting to fix something, but not sure what. It was reading the HD at full speed for over a day. It was effectively stuck in a loop. It was eating up all of his IO and also a large portion of his CPU, and a modern 8 core server with several gigs of ram. Also, because the FS was stuck trying to fix the data, the computer refused to shutdown as the FS would not release.
He had to do a forceful shutdown and that messed up his FS even more. He said the HD was left in a corrupted state and no tools would fix it.Luckily this was a test machine and he had a full back-up of the data. He reformatted and put EXT on and it worked fine.
BTRFS does not sound ready.
Re:My experiences with btrfs by Anonymous Coward · 2011-06-09 03:03 · Score: 0

Well, it's not ready. There's no stable release yet. This is why you don't run Fedora on a production server.
Re:My experiences with btrfs by arth1 · 2011-06-09 03:13 · Score: 3, Informative

With RAID 0 you get twice the amount of the smallest unit.
Using a 40 GB and an 2 TB HD will give you an 80 GB RAID 0.
Re:My experiences with btrfs by Anonymous Coward · 2011-06-09 03:24 · Score: 0

BTRFS does not sound ready.
It's ready to go into an Alpha test version of Fedora 16, so that it can get some serious testing. Whether it's stable enough to stay there for release is a different story.
Re:My experiences with btrfs by Rich0 · 2011-06-09 03:45 · Score: 2

Does btrfs actually stripe like this, or does it simply keep a copy on two volumes for RAID1, and spread data around for RAID0?
You can tell btrfs to even keep two copies on the same volume if you want, I think.
They call it RAID, but I don't think it is really the same thing. The RAID5-like features and reshaping don't exist yet (the last time I checked). Then again, maybe it supports both modes of operations - if there is one thing about btrs is that it has a million optional features.
Re:My experiences with btrfs by Anonymous Coward · 2011-06-09 06:17 · Score: 0

That's funny. A while back I read this guy's blog about how he was making a movie that would revolutionize hollywood, be bigger than The Hangover (because it's more realistic), the best diarrhea scene ever, etc. Anyhow, his movie lost 10 million dollars and, more importantly, nils is fat, although you'd think he might start losing weight now that he's totally broke.
Re:My experiences with btrfs by Anonymous Coward · 2011-06-09 08:40 · Score: 0

I know I'm being slightly unfair, but I'm secretly glad they are pushing it. Obviously with such a large user base switching to btrfs, there will be many more bug reports and perhaps more effort into moving the filesystem in a more stable direction. I don't envy those people though!

What about fsck support? by edeefelt · 2011-06-09 02:33 · Score: 2

What about fsck support? The last time I checked, btrfs does not support this important feature to allow recovering from hard disk issues.

Re:What about fsck support? by Anonymous Coward · 2011-06-09 03:16 · Score: 0

Because it is not a journalised FS, it's a COW FS, it does not need to go offline to be repaired. It can repair itself online or allow you to mount the last working/clean version of the FS.
Re:What about fsck support? by caseih · 2011-06-09 03:28 · Score: 2

I've ran BtrFS's arch rival, ZFS for years, and I have never ever had to fsck the disk, even after power outages and crashes (yes Solaris crashes rather spectacularly sometimes). In theory a good file system should always be in a consistent state and never require fscking. Of course you could mean trying to fsck a disk when a hard drive starts failing, but I still don't see how that is useful; fscking a failed drive might just stir the data more. I'll settle for being able to pull off as much data as I can, fsck or no fsck.
Re:What about fsck support? by Gaygirlie · 2011-06-09 03:33 · Score: 1

Because it is not a journalised FS, it's a COW FS, it does not need to go offline to be repaired. It can repair itself online or allow you to mount the last working/clean version of the FS.
Well, superblocks et al can still get corrupted, and at the moment the only way of repairing issues seems to be full rebalancing of the whole filesystem. That is VERY time consuming, not to mention that it causes loads of unnecessary I/O. An fsck utility could just instead rebalance the parts that need it resulting in much less overhead and time spent.
Re:What about fsck support? by nutznboltz · 2011-06-09 05:12 · Score: 1

If there is no fsck for btrfs then what is this?
http://git.kernel.org/?p=linux/kernel/git/mason/btrfs-progs-unstable.git;a=blob;f=btrfsck.c;h=63e44d1dbc26f2ee9f6ef29c08ae0eb9d19e48db;hb=HEAD
Re:What about fsck support? by Anonymous Coward · 2011-06-09 06:24 · Score: 0

In theory, but when you deal with bad drivers, kernel bugs, bad cables, etc you can have other sources of problems than just a failing drive. Also, what recovering from rouge programs overwriting critical headers, how do you get to the backup ones?
Re:What about fsck support? by Anonymous Coward · 2011-06-09 07:07 · Score: 0

This? uh... Don't pay any attention to the man behind the curtain!
Re:What about fsck support? by Anonymous Coward · 2011-06-09 07:18 · Score: 0

no fsck yet. I found this out after a power outage last month... spare superblocks didnt work either, and that,s the most stable btrfstool I could find.
this should all be sorted by fedora users soon enough.
Re:What about fsck support? by jvillain · 2011-06-09 07:20 · Score: 1

It's fairly new so most people probably don't know about it. It has been available in Rawhide for a couple of months or so now.
Re:What about fsck support? by PipsqueakOnAP133 · 2011-06-13 15:02 · Score: 1

I run ZFS on my personal file server with questionably old 160GB drives.
There isn't a "fsck" per say, but you should do "zpool scrub" periodically, which is kinda similar.
What it actually does it read all your data and checks the checksum. If the checksum fails, it'll know to try whatever it can within your settings to make redundant copies of it (if you allowed it to).
What this is useful for is more to see if your drives are about to kick the bucket out from under you. :P
ZFS is awesome.

Gummi Bears! by Anonymous Coward · 2011-06-09 02:37 · Score: 0

Dashing and daring,
Courageous and caring,
Faithful and friendly,
With stories to share.
All through the forest,
They sing out in chorus,
Marching along,
As their song fills the air.

Gummi Bears!!
Bouncing here and there and everywhere.
High adventure that's beyond compare.
They are the Gummi Bears.

Magic and mystery,
Are part of their history,
Along with the secret,
Of gummiberry juice.
Their legend is growing,
They take pride in knowing,
They'll fight for what's right,
In whatever they do.

Gummi Bears!!
Bouncing here and there and everywhere.
High adventure that's beyond compare.
They are the Gummi Bears.
They are the Gummi Bears!!

i like my filesystems.. by Anonymous Coward · 2011-06-09 02:47 · Score: 1

..how i like my women ... FAT and 16

Re:i like my filesystems.. by f8l_0e · 2011-06-09 06:14 · Score: 1

I hope you like doing all your mounting on FreeBSD, that way you'll be used to jails.

Never mind by bigjocker · 2011-06-09 03:00 · Score: 1, Funny

ReiserFS will kill it

--
Life isn't like a box of chocolates. It's more like a jar of jalapenos. What you do today, might burn your ass tomorrow.

Re:Never mind by Anonymous Coward · 2011-06-09 05:22 · Score: 0

maybe even murder and bury it in the backyard.

Availability Notice by mgmartin · 2011-06-09 03:34 · Score: 4, Insightful

Quoted from man mkfs.btrfs on Fedora 15.

...Btrfs is currently under heavy development, and not suitable for any uses other than benchmarking and review.

That sure limits the uses of a default Fedora installation.

Re:Availability Notice by Gothmolly · 2011-06-09 06:57 · Score: 2

You do know what Fedora is supposed to be, right ?

--
I want to delete my account but Slashdot doesn't allow it.
Re:Availability Notice by Anonymous Coward · 2011-06-09 09:20 · Score: 0

this is a gamble, they;'e trying to push devs to make better tools for btrfs.
kind of a sink or swim moment, throwing your kid into the pool to learn how to swim is damn scary and i hope that the devs appreciate the risk that they are taking here. there are better ways to learn how to swim!
Re:Availability Notice by Anonymous Coward · 2011-06-09 10:25 · Score: 0

This is also found as a disclaimer on the btrfs Wiki, which would be more authoritative.
Re:Availability Notice by rdnetto · 2011-06-09 16:24 · Score: 1

Is anyone else thinking of when Ubuntu implement ext4 support? Turned out there was a major bug that caused kernel lockups when emptying the trash.
I can only imagine something similar will happen here...

--
Most human behaviour can be explained in terms of identity.

BTRFS and RAID5/6 by spain · 2011-06-09 03:39 · Score: 1

This is good news, I've been thinking about trying BTRFS out for a while now.

One big question, for me at least - does BTRFS have full built-in support for RAID5 and RAID6? The last time I checked it was still "under development".

Hierarchical File System? by drunkahol · 2011-06-09 03:45 · Score: 3, Interesting

I'd like to see btrfs implement a proper block tiering system. They're doing something for storing "hot" blocks on SSD, but what about giving us the full monty? Where I can rank storage types myself, assigning a different cost to each type. Hotest blocks in RAMdrive (battery backed of course), next step down fast SSD and then slower SSD, followed by Fibre, SAS, SATA and finally tape. Yes tape. Just create snapshots as backups. These blocks then sit there and drift down to tape storage when required.

Funny how this has all been done before when disks were really slow. I suppose it's the big gap of incredibly fast SSD's (compared to mechanical) that's resurrecting these ideas. With this done, btrfs could be stuck in as a relatively cheap SAN/NAS solution. All done in a big tower case in my loft.

Re:Hierarchical File System? by drunkahol · 2011-06-09 03:52 · Score: 1

Oh - and inline de-dupe. Much discussion on it in some lists, but it's a killer feature that would be of huge benefit in the right place.
Argue all you like where that right place is, but an admin ought to have the right to use a tool such as dedupe where they like - even if that may not be your ideal use for dedupe.
Re:Hierarchical File System? by badkarmadayaccount · 2011-06-10 06:52 · Score: 1

Quit fucking up the layering, a tiered block device driver would do the trick just as well.

--
I know tobacco is bad for you, so I smoke weed with crack.
Re:Hierarchical File System? by maraist · 2011-06-17 01:30 · Score: 1

mdadm + drbd + lvm + ext4 (throw crypto somewhere in there too). I've found the layers to be frustrating when deviating from initial install. And I've also found installation of new machines to rarely support the particular layering model I'm interested in. So I typically have to do a complex post-install reconfiguration. If, instead the layers were flatened (and supported zfs style RAID-5 write-hole elimination), my life would be make significantly easier. I'm not saying btrfs's particular architecture, but the ability to have the 'layers' work in tandom instead of invocation-level layers. Define plugable aspects of block mapping that are part of a common OS operation.

I doubt this would be as efficient as a monolithic flattened file-system, nor as robust as monolithic or even layered (as the number of combinations of event-condition grows factorially). But when I design software, there is a careful balance of layering v.s. aspect-orientation. Service X can do 10 things, each of which are configured at load-time as delegates. Of which 4 things might be noops for any given configuration.

cache-mapping, block filtration (e.g. encryption / checksumming / block striping (RAID-0/5)), write-block consolidation (e.g. disk-geometry elevators / RAID-Z), physical disk/offset block mapping (including remote-node replication), etc.

--
-Michael
Re:Hierarchical File System? by badkarmadayaccount · 2011-06-18 02:39 · Score: 1

I thin the issue here is that ZFS has great admin tools OOTB, and the usual admin stack has next to none (good ones). And wtf is up with the docs\? It's a little personal - I need to resize some LVM volumes by merging the LVM phy partition with the one next to it, and I have no tool, or clue, as to how to do it. I agree on you point of using a mixed modularity strategy, though I'm pretty sure it can all be done with some nice clean block devices (I'm anal on keeping the kernel interface clean more than linus, even though I'm not a programmer). Check out the cool tricks IBM pulled with VSAM.

--
I know tobacco is bad for you, so I smoke weed with crack.

Error: Sparse file not found by Anonymous Coward · 2011-06-09 04:16 · Score: 0

Error: Sparse file not found: Why oh why is BTRFS not wanting to create a nice sparse file for me on boot? Oh wait! I know! Its because BTRFS *CAN'T* make a sparse file. Its not something that BTRFS does. Or at least not yet.

Restore from suspend by PixelSmack · 2011-06-09 04:46 · Score: 1

There is currently alot of work to be done, if you have btrfs mounts at the moment in F15 then you system hangs a few seconds after restoring from a suspend.

Squishy Bears! by Anonymous Coward · 2011-06-09 05:30 · Score: 0

They're the Squishy Bears
and they're right over there.
They're the squishiest bears you know.

They've got squishy hairs
'cause they're Squishy Bears.
Here come the swell Squishy Bears!

Too bad we're already forced into LVM by Sylak · 2011-06-09 05:35 · Score: 1

it means that major Btrfs features such as RAID and LVM capabilities will not be forced onto users."

It's too bad that the default fedora setup wants to set up an LVM already even with ext4, and yells at you when you try to not use an LVM

Yes it does by Sycraft-fu · 2011-06-09 06:18 · Score: 1

No matter how well you design your FS, errors can happen. Generally it is because of hardware below it but the cause isn't important, the recovery is. That's why NTFS has chkdsk. Many people don't know it and assume it isn't needed because it runs extremely rarely, a user will likely never see it. It isn't like the old FAT32 days where you needed to run it on every crash. However it is still there, and we (IT) still use it from time to time. If something goes wrong, the filesystem can be left in a state where you need to run a tool to fix it and recover what you can.

Same deal with BTRFS. It doesn't need a fsck tool for daily use, but you really want something like it if shit goes really wrong.

Fuck it up just like ZFS did to Solaris? by Anonymous Coward · 2011-06-09 06:43 · Score: 0

New shiny!!!!

MUST

FUCK

WITH

FILESYSTEM

THAT'S

WORKED

FOR

DECADES!!!

Not only that, ZFS is slug-slow. And the arrogance of "we're perfect, we don't need an fsck tool" is really obnoxious.

I don't see quite the "La la la! We're the GREATEST!!!" attitude exuding from BTRFS, so maybe it has a chance.

Re:Fuck it up just like ZFS did to Solaris? by rubycodez · 2011-06-09 08:37 · Score: 1

no problem with that on Slowlaris, since they went from BSD based to that System V R4 the thing became a pig anyway. It was like getting the RAM and processor speed cut in half on the Sparc V and Sparc 2 workstations I adminned at the time. A slow-as-molasses-in-January filesystem is the finishing touch

ZFS isn't "just" a filesystem by toby · 2011-06-09 07:41 · Score: 1

And calling it one was a poor marketing move on Sun's part. In any case, ZFS (and eventually btrfs) will obsolete write-in-place filesystems like UFS (or have already obsoleted, depending what you've been using in the last 7 or 8 years since ZFS went production).

--
you had me at #!

Re:ZFS isn't "just" a filesystem by rubycodez · 2011-06-09 08:44 · Score: 1

too bad UltraSparc based hardware became obsolete first. who'd spec that crap for a new system when powerpc and 80+ core x86-64 systems can be had

This is why I left Red Hat Behind by rubycodez · 2011-06-09 08:25 · Score: 1

Red Hat turned against we IT geeks who got them accepted into the corporate environment, and instead made the hobbyist user to have a guinea pig distro with unstable things in it like BTRFS. Sure, I'm excited about the day when butterfs will be a stable option, but that isn't yet. Screw Fedora, Screw Red Hat, use something else where the care about stability and where the hobbyist/user/server versions are all just kernel and package changes on the same distro.

Re:This is why I left Red Hat Behind by mu51c10rd · 2011-06-09 08:42 · Score: 2

The fragmentation already exists. Need a stable, supported release? Use RHEL. Need to use it without the Red Hat strings attached but still have the stability? Use CentOS. Want the hobbyist bleeding edge? Use Fedora.
Re:This is why I left Red Hat Behind by Anonymous Coward · 2011-06-09 10:59 · Score: 0

Scratch CentOS. That distro is undermanned and failing fast. CentOS 6 isn't even out 6 months after RHEL-6. Try Scientific Linux.
Re:This is why I left Red Hat Behind by rubycodez · 2011-06-09 16:52 · Score: 1

uh huh, and Scientific Linux hasn't got 5.6 out yet because they were tripping all over themselves to shove 6 out the door

Why I left Red Hat..... by cyberkahn · 2011-06-09 08:25 · Score: 1

I don't really need to say much more. Fedora is just too bleeding edge even for non-production IMHO. I don't want to boot up my box and have my file system screwed. Sorry Red Hat. You should go back to the old model of eating your own dog food. Perhaps a model like Ubuntu with a Red Hat LTS and a Red Hat Latest Version, but the latter being a little more stable than Fedora. I digress, this is why I am on Ubuntu now. It's not perfect, but it has been a much more positive experience for me than running Fedora. Even on non-LTS releases I haven't had a update blow up a system.

Btrfs by Anonymous Coward · 2011-06-09 08:26 · Score: 0

Bit rot filesystem?

I still haven't recovered from Broken Shit in f15 by Anonymous Coward · 2011-06-09 09:42 · Score: 0

That's nice and all, but I'd kinda like the next upgrade to work much smoother than the last.

Gnome is broken for multiheaded ATI users. Apparently there's an option to force a downgrade to gnome 2.x, but I can't login to gnome to see it.

3 devs here, all with the same machines, multiple HD6450 cards, multiple monitors. All got the same problem, gnome is fucked.

Your presence requested 2 answer simple question by Anonymous Coward · 2011-06-09 10:01 · Score: 0

http://tech.slashdot.org/comments.pl?sid=2225174&cid=36390518

Anyone able to access their forums? by Anonymous Coward · 2011-06-09 11:16 · Score: 0

Have they already made the switch?

I'm referring to http://forums.fedoraforum.org.../

u r a stupid trollbag by drinkypoo · 2011-06-09 13:58 · Score: 1

Your presence requested 2 answer simple question (Score:-1)
by Anonymous Coward on 06-09-11 15:01 (#36394150)

http://tech.slashdot.org/comments.pl?sid=2225174&cid=36390518

This is why people like me think you're a fuckhead, apk. You log in as AC so you can sign some posts and not others. Go piss up a very short rope.

--
"You're right," Fisheye says. "I should have set it on 'whip' or 'chop.'"

Hahahaha running from facing the music, troll? by Anonymous Coward · 2011-06-09 15:12 · Score: 0

Just answer a simple question here that was asked of you there http://tech.slashdot.org/comments.pl?sid=2225174&cid=36390518 You seem to troll others but when it's done to you? Gee, different story huh? You sure dish it out but you can't take it. Toss all the names you want, but you have to eat your words again, whimp.

People like you? You mean trolls?? by Anonymous Coward · 2011-06-09 15:16 · Score: 0

You may think he's a fuckhead, but we know you're an off topic troll that can't handle answering a simple question and had his ass handed to him for trolling and then runs like a little beyotch.

Hahahaha "dwinky-POO" is "ang-wee" by Anonymous Coward · 2011-06-09 15:23 · Score: 0

Poo wittle dwinky-poo! Hahahahaha

Now, now kids: Don't pick on wittle dwinky-POO by Anonymous Coward · 2011-06-09 15:27 · Score: 0

Dwinkypoo trolls everyone else but can't handle it in return. Answering up to his own mess he causes and if it's done to he? Well now, you can see his petulant childish reaction. Poo wittle dwinky-POO is afraid to answer questions that will make him dwinky his own POOP. Hahahahahahaha.

Learn to spell you illiterate dolt: Whining by Anonymous Coward · 2011-06-09 15:35 · Score: 0

See subject and learn to spell you illiterate dolt. It's not 'whigning' you moron. And, Nerd? You don't even qualify you poor little excuse for a wannabe. You're too damned stupid. You can't even spell right! You seem to speak for everyone here. You don't. Many people love to learn new things, except for limited mentally challenged goofs like yourself dolt.

Registered LUSERS can do the same too by Anonymous Coward · 2011-06-10 00:59 · Score: 0

Who do you *THINK* you are fooling, troll? You have the option to reply as anonymous also. You're so full of it troll, it makes me laugh. Especially when you are caught with your pants down, trolling, and you refuse to answer the question here http://tech.slashdot.org/comments.pl?sid=2225174&cid=36390518 on if you showed up off topic and trolling in the initial reply to you here. I think you're a bit angry with yourself for being easily seen through and that your favorite color must be "transparent".

Re:Registered LUSERS can do the same too by drinkypoo · 2011-06-10 03:08 · Score: 1

Nice, you spent at least five times longer in this part of this thread than I did. Let's see if I can do it again.

--
"You're right," Fisheye says. "I should have set it on 'whip' or 'chop.'"
Re:Registered LUSERS can do the same too by Anonymous Coward · 2011-06-10 03:24 · Score: 0

And, do what again? Show you're a cowardly troll that avoids SIMPLE questions put to he, here: http://tech.slashdot.org/comments.pl?sid=2225174&cid=36390518
?
Because it shows you for who & what you REALLY are, Linux troll?? Absolutely. Caught red-handed, with your pants down troll, lol... can't "face the music" of your OWN screwup, troll?? Again, absolutely. Seems the troll called "drinkypoo" can troll others, but when it's done to he in a retrolling? He runs away... lol, & from a SIMPLE question.

Good Info by Anonymous Coward · 2011-06-14 05:41 · Score: 0

Thank you, http://exercisesto-reducetummy.com/articles/workouts-for-abs/

fedora 15 :( by Anonymous Coward · 2011-06-19 09:20 · Score: 0

hi friends reacently i have created a blog of my own Http://www.mobilefuse.blogspot.com

after that while i was chatting with some unknown friend in facebook we started little bit quarrel i donno what happened lotz of virus effected to my system :(

cant delete them nor cure them, but with one of my friends suggestion i came to this linux o.s for the 1st time :D

i really feels like windows is completely shit compared to linux o.s coz mainly of hackers exe files and more

so linux is better for now but i found some news in wekipedia that virus rate is increasing day by day on linux o.s

so, lately i installed linux mint (this is really awsome o.s till now i ever used ^_^) after that i found some latest o.s released i.e., macbuntu 11.04 this os is good but the o.s is new and had sooo many bugs :( soo i searched for some other new o.s then i found fedora 15 :D

fedora 15 is really awsome outstanding cool o.s i ever used and graphics are amazing but :( i didnt found drivers :'( im not able to play audio in my laptop (dell 14r inspiron)
no 1 helped me too sooo plz fix that and make fedora 16 the best o.s in the market i will share and suggest this too all my friends :D

mdadm woes gone, but replaced by btrFS woes. by Anonymous Coward · 2011-06-19 11:55 · Score: 0

How GRACIOUS of Fedora not to "force" btrFS's LVM-equivalent & RAID-equivalent on users of Fed16 ...especially since btrFS can't even do all the things that mdadm does yet: e.g. RAID-1 on 2 partitions (or "subvolumes") then RAID-10 on 4 partitions (or "subvolumes") under the same root... or RAID and non-RAID partitions spanning ONE hard-partition so that dm-crypt only expects ONE password (or keyfile).

"it means that major Btrfs features such as [its LVM & RAID equivalents] won't be forced onto..." ...so does that mean the fsck isn't a "major feature"?? With _filesystem-level_ data corruption as a risk, it's a major feature, and this UNTESTED fsck IS indeed being pushed on Fed16 ordinary (PRODUCTION SYSTEM) users despite that no btrfsck was even released as of Fed15.

Hylandr, if you take a snapshot, it must be stored not only on btrFS, but on _THE_ btrFS filesystem that it's imaging; in your hypothetical scenario that means your backup (image) is ON the RAID system that just crashed (since btrFS subvolumes currently can't mix RAID levels, or RAID w/non-RAID. If someday they could, I'd reconsider btrFS.): that's not a reliable backup and rsync (or dozens of others) is a much better way to backup your data, preferably on a disk separate from your btrFS disks, or better, offsite. You're trading in mdadm "woes" for even bigger woes -- especially if you don't wait AT LEAST a year for btrFS to make the necessary improvements to its mdadm-equivalent.

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Fedora 16 To Use Btrfs Filesystem By Default

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