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Ext4 Advances As Interim Step To Btrfs
Heise.de's Kernel Log has a look at the ext4 filesystem as Linus Torvalds has integrated a large collection of patches for it into the kernel main branch. "This signals that with the next kernel version 2.6.28, the successor to ext3 will finally leave behind its 'hot' development phase." The article notes that ext4 developer Theodore Ts'o (tytso) is in favor of ultimately moving Linux to a modern, "next-generation" file system. His preferred choice is btrfs, and Heise notes an email Ts'o sent to the Linux Kernel Mailing List a week back positioning ext4 as a bridge to btrfs.
...and that's it's biggest problem. ZFS duplicates a lot of functionality that belongs outside of a filesystem. All of the above can already be done using any Linux filesystem, so why keep around a second copy of all that code that implements those features for just a single filesystem?
ReiserFS was (is) in a similar situation, where it also duplicates a lot of functionality that doesn't belong in the filesystem. Not only does this make it harder to maintain, but it makes a lot of features filesystem specific that shouldn't be.
Game! - Where the stick is mightier than the sword!
Why not? It's a good analogy for FOSS after all. Great software, robust and all, but her face...
Starbucks, Harbuckle of Breath.
(b) the maintainer is not a crazy man and works well with other LKML developers
Also important, he might be more focused due to not being in prison for first degree murder
Negative moral value of force outweighs the positive value of good intentions.
"Couldn't they come up with a better name than "BuTteR FaSe?" I know I can't be the only one who read it like that. Call it anything but that."
I read it as:
BeTteR FileSystem
I guess we'll have to part was :P
The things you think belong outside of a filesystem only 'nelong' there because that's what years of narrowminded developing have tought you. Look at it this way: /everything/ related to filestorage is managed by ZFS. What could be more convenient than that? Because of this, ZFS can do things much faster and much more reliable than any combo of LVM with a filesystem. Why chain together tools yourself, and manually think about things you really shouldn't be thinking about, when you can have a good filesystem take care of it for you.
ZFS is easier to maintain, from a users perpective (and that's the job of development, to make usage easier, not ever the other way round).
Yeah, I remember they used to talk about this in the Gentoo handbook; use ext2 for /boot, but ext3 for everything that you actually care about.
so I think that journalling will become obsolete in some near future.
I bet in 1992 you were still thinking color TV's wouldn't last either . . .
Look, a UPS is a great thing. I run one myself. Heck with more and more people switching to laptops a lot of people are running a "UPS" without even realizing it. The simple fact though is that modern processors and disks are so fast that the minimal speed impact of journaling is barely noticeable. It's certainly not worth giving up over some marginal speed gains.
I mean we're talking about a world where people will give up tons of speed in their computer just to make the WINDOWS WOBBLE when you move them, or to make teddy bears wave at them from the system tray. Do you honestly believe that they're going to risk having their files corrupt on an unexpected power outage for a fraction of a percent increase in meaningful speed?
"People who think they know everything are very annoying to those of us who do."-Mark Twain
Look at the bottom of the page. That's from 2003. Of kernel 2.6.0. A lot of code changed since then.
I'm not sure what exactly you mean by this. Latency is mostly influenced by the hard disk. And on a desktop the disk shouldn't be a bottleneck anyway.
Except there's lots and lots of those files in a modern Linux system. Config files, icon files, and small libraries for instance. Additionally many files are searched in different paths, making a fast directory search important.
Just as a RAID is not a backup, an UPS isn't a disk journal. One of those days you'll get a long outage, or the power cable will turn out to fit badly into the power supply, have a kernel panic, the UPS won't switch to battery fast enough, etc. And then after several minutes of fsck something important might end up broken.
If the journal causes you a noticeable slowdown you probably aren't a typical user. In typical usage the disk should be mostly idle after boot.
I don't see a point in going forward insanely fast without brakes. I'll take the safety. I have an UPS on every computer, and still have a journalled FS, because there were times when the UPS was of no help. Like yesterday, when I upgraded my laptop's RAM, booted it, and found that with more than 2GB RAM, the BIOS maps the video RAM above 4GB. The video card showed its displeasure with that state of affairs by corrupting the display and locking up. Had no choice but to powercycle the box.
Yeah, because systems never kernel panic, or crash for any other reason than power outages... Wake me up after you've been waiting for fsck to finish on your 1TB drive and it's been running for the last 72 hours.
Whether or not you've had a system shutdown uncleanly in the past, you certainly will at some time in the future, so why not just use ext3 and save yourself the headache of a 3 day long fsck?
It's also painfully obvious that you've never worked as a sysadmin before. You try explaining to your manager that the reason why your company's server will take 3 days to come back online is that you wanted to save a few microseconds of latency when users were accessing files...
"When the president does it, that means it's not illegal." - Richard M. Nixon
I used to do that, and then I got a UPS instead and switched back to pure ext2. The performance hit from journalling is simply too high to tolerate. A decent UPS (pretty much anything made by APC) will prevent the crashes in the first place, solving the problem completely and without any unnecessary overhead. With UPS prices being as low as they are, there is no excuse for not having one, so I think that journalling will become obsolete in some near future.
Our industrial UPS (which is orders of magnitude more reliable than any APC product ever made) recently exploded, burnt, and shorted out the entire building's power. It spiked thousands of volts through the protected equipment and destroyed a half-dozen servers. The fire was fierce enough to cause our fm200 system (halon equivalent) to dump, which put out the fire before the main battery bank was breached.
This was the first time I've ever seen an UPS bigger than a Chrysler fail, but I've seen dozens of failures from those crappy little APC units. At one time I had a stack of burnt-out ones in my basement (I used to salvage the batteries for cash).
If your disaster survivability plan depends on any single piece of hardware never failing, it's no good. Offsite backup is your friend.