Linux 3.2 Has Been Released

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Posted by samzenpus on Wednesday January 4, 2012 @02:06PM from the check-it-out dept.

diegocg writes "Linux 3.2 has been released. New features include support for Ext4 block size bigger than 4KB and up to 1MB, btrfs has added faster scrubbing, automatic backup of critical metadata and tools for manual inspection; the process scheduler has added support to set upper limits of CPU time; the desktop responsiveness in presence of heavy writes has been improved, TCP has been updated to include an algorithm which speeds up the recovery of connection after lost packets; the profiling tool 'perf top' has added support for live inspection of tasks and libraries. The Device Mapper has added support for 'thin provisioning' of storage, and a support for a new architecture has been added: Hexagon DSP processor from Qualcomm. New drivers and small improvements and fixes are also available in this release. Here's the full list of changes."

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Btrfs by davegaramond · 2012-01-04 14:09 · Score: 4, Interesting

So does this mean I can start using btrfs, at least for personal workstations? I've got a new box at the office waiting to be setup, with a 120GB Corsair SSD as the main system disk, normal 2TB harddisk as backup/media storage. Will be using Debian. Should I use btrfs?
1. Re:Btrfs by Anonymous Coward · 2012-01-04 14:15 · Score: 5, Interesting
  
  Short answer: no.
  Long answer: Please! The more people exercising the code, the more bugs will be revealed, and the more confident the developers can be. But you will have to be ready for some performance regressions and data loss danger. For the brave.
2. Re:Btrfs by francium+de+neobie · 2012-01-04 14:17 · Score: 5, Informative
  
  There's no fsck.. So unless you're 100% sure your Linux machine never crashes and your power supply is never interrupted - don't.
3. Re:Btrfs by Anonymous Coward · 2012-01-04 14:23 · Score: 3, Interesting
  
  Even without any crashes or power fails, I've managed to corrupt BTRFS in testing, with just a defrag (as recently as 3.2-RC6). I wouldn't look at BTRFS for a while, at least until it's no longer marked experimental. By all means test away, but don't assume you'll be able to get to any data you put in it.
4. Re:Btrfs by Anonymous Coward · 2012-01-04 14:32 · Score: 5, Interesting
  
  Performance is still pretty bad, especially when deleting many small files. It can take minutes with BTRFS, while EXT4 does it almost instantly in comparison.
5. Re:Btrfs by mattbee · 2012-01-04 15:11 · Score: 3, Interesting
  
  btrfs is tanatlizing for VMs because of the copy-on-write file behaviour (i.e. "cp --reflink a b" creates b instantly regardless of the size of a), but http://lists.fedoraproject.org/pipermail/devel/2011-July/154251.html is still an issue, as far as I'm aware. So storing VMs, where you access them with O_SYNC, just gets slower over time until it's unusable. I'm not quite brave enough to suggest that any of our customers use it, at least until there's a working fsck.
  
  --
  Matthew @ Bytemark Hosting
6. Re:Btrfs by 0123456 · 2012-01-04 15:27 · Score: 4, Informative
  
  If this is the case, whats the fucking point really? BTRFS was heralded are the replacement for ZFS, but you are seriously telling me that after all this time, you can still lose a large amount of data and end up with a corrupt filesystem after such a trivial thing as a powerloss? Really?
  BTRFS has only been around for a short time and I don't believe any OS uses it as the default filesystem yet. And you're surprised that it still has problems?
  And I don't remember anyone claiming that BTRFS would replace ZFS, merely that it would eventually have many of the same capabilities that ZFS has.
7. Re:Btrfs by icebraining · 2012-01-04 15:28 · Score: 2, Insightful
  
  even Windows hasn't had such issues in over a goddamn decade.
  Windows is not a filesystem. And that's only relevant if NTFS has the same features as ZFS: Ext doesn't have the same issues either.
  
  --
  Dilbert RSS feed
8. Re:Btrfs by tetromino · 2012-01-04 15:41 · Score: 5, Insightful
  
  If this is the case, whats the fucking point really?
  The fucking point is to encourage beta-testers. Bleeding-edge users who know what they are doing and don't care about data loss are being offered the chance to test a new and interesting filesystem and (ab)use it in ways that upstream developers had not thought of, hopefully uncovering major bugs before the thing will get marked as feature-complete and enabled by default for new installs by major distros.
9. Re:Btrfs by thomas8166 · 2012-01-04 15:42 · Score: 2
  
  Well, technically there is, but since it doesn't repair errors, it's not much good.
  
  --
  I make hardware RNGs, which give 2.5849625 bits of entropy per use in theory (actual performance dependent on usage).
10. Re:Btrfs by adolf · 2012-01-04 16:34 · Score: 2
  
  Windows is not a filesystem.
  Windows may not be a filesystem, but it only ships with one sane choice of general-purpose filesystem, and that choice is NTFS. Therefore, Windows == NTFS for the purpose of a discussion in the context of filesystems. Not literally, but plainly for all intents and purposes.
  (Counterarguments about Windows also shipping with crappy filesystem(s) needn't apply, since Linux/*BSD ships with those too. And HPFS, the only other then-viable choice from IBM/MSFT, and perhaps the only one that Linux and Windows and OS/2 all supported properly at the same time, got killed a long long time ago.)
  (Disclaimer: This is does not represent my opinion on anything. It simply is a representation of how things are.)
  
  --
  Kid-proof tablet..
11. Re:Btrfs by ILongForDarkness · 2012-01-04 17:16 · Score: 4, Funny
  
  format /dev/null as BTRFS then?
12. Re:Btrfs by waveclaw · 2012-01-04 17:23 · Score: 5, Insightful
  
  Bleeding-edge users who know what they are doing and don't care about data loss are being offered the chance to test a new and interesting filesystem
  
  Amen.
  fsck's only job is to make that junk that was a filesystem look something like a filesystem again. Nothing in there about making it look like the particular filesystem you used to have. fsck is not backups. fsck will not (necessarily) get your data back. fsck may eat kittens on a bad day. What fsck does hand back to you should not be trusted and should certainly be verified.
  If you think that pulling most of what was /home, /var, /srv or /opt out of lost+found is fun, just remember that corrupted directory and filenames get named after their inodes. Nothing like trying to figure out of 1234567 or 1234568 was the start of the quarterly financials report.
  If you are relying upon a fsck to get your data back after a power outage, you have more faith in your filesystem than you should. It's a nice validation tool, with the caveat that a False Negative means you go back to using a damaged filesystem for more fun later, rather than now.
  BUT if you have backups, please do test. Having talked to the BTRFS team directly at LINUXCON, Mr. Chacon and folks are pretty cool about getting feedback. And you can do nifty things like snapshots for backups on RAID10 or thin disks on virtual machines which don't inflate during formatting.
  For many filesystems, failing a fcsk means reaching for the format tools and the last (verified) backup. You are backing up everything, right?
  
  --
  
  "You cannot have a General Will unless you have shared experiences. You cannot be fair to people you don't know."
13. Re:Btrfs by Sloppy · 2012-01-04 17:50 · Score: 4, Funny
  
  Short answer: no.
  Long answer: Please!
  In other words, "better you than me."
  
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  As copyright owner of this comment, I authorize everyone to defeat any technological measure which limits access to it.
14. Re:Btrfs by adolf · 2012-01-04 18:44 · Score: 4, Interesting
  
  I'm just one man, but I've tried hard over the past decade to find a real problem with NTFS (and I've been sternly bitten by ReiserFS and ext2/3 over that same period), and just haven't: It's worked on the many hundreds of computers I've fondled just fine, and even seems to survive mild hard disk failure with some amount of reasonableness.
  What, in your opinion, makes NTFS a pain in your ass? (I ask because I'm curious and want to avoid any such scenario, not because I am predisposed to attack your observations.)
  
  --
  Kid-proof tablet..
15. Re:Btrfs by subreality · 2012-01-04 19:09 · Score: 5, Informative
  
  BTRFS is journaled (the log tree), so you don't lose data due to a power failure. It just replays the journal when you mount it again.
  btrfsck is only really needed to recover from something unanticipated happening. Like software bugs. The kind that you'd expect in a new filesystem. So it's absolutely not ready for prime-time until a fsck is released.
  For non-critical systems it's completely usable for people who like to experiment with the new toys. I've been using it for a year on my laptop (including multiple power losses and other shenanigans) with no problems.
  My experience so far:
  Good:
  Snapshots (and subvolumes) are a killer feature. Having hourly and daily versions of everything is wonderful. I have subvolumes for root (@) and /home (@home). If I want to roll back my entire system but keep my homedir, I can simply: "cd /snap ; mv @ @-2012.01.04-broken ; btrfs subv snap @-2012-01-02--00-40-39-apt @ ; reboot". Translated - Save a copy of my current root; create a new root from the last snapshot that was automatically created when I last ran apt-get ; then reboot (all shutdown continues in the @-2012.01.04-broken subvolume, it doesn't corrupt the new @). Killer. Feature.
  Bad:
  fsync is god.awful.slow. And dpkg does a whole lot of fsync. It's completely unacceptable performance, and either btrfs has to get faster or dpkg has to be a little more miserly with fsync. If dpkg could send write barriers instead of syncs it'd probably solve it, but who knows. For the time being: "apt-get install eatmydata; ln -s `which eatmydata` /usr/local/bin/aptitude ; ln -s `which eatmydata` /usr/local/bin/apt-get" . eatmydata preloads a library that overrides sync and fsync (they're simply ignored). dpkg is now screaming fast, but I run the risk of completely screwing its metadata if there's a crash or poweroff while it's doing something. So the solution is I have a /etc/apt/apt.conf.d/80-snapshot that creates a snapshot before every apt run. If something goes wrong, I just roll back the system like I mentioned under Good.
  So in summary: Some good, some bad, definitely not fully baked yet, but completely usable if you're adventurous. No fsck required. Yet. Keep backups. :)
16. Re:Btrfs by thegoldenear · 2012-01-04 19:29 · Score: 2
  
  What part of "better you than me." sounded to you like he was bitter? I read it as quite humorous.
17. Re:Btrfs by dbIII · 2012-01-04 19:55 · Score: 4, Informative
  
  Performance can be a pain with very large files and with a lot of very small ones, and it's the people with such uses that are pissed off with NTFS - I'm not sure that can be classed as a "real problem".
  Any security considerations can be ignored since if you took those seriously you wouldn't be advertising something even worse in that respect than plain 20 year old FTP.
18. Re:Btrfs by adolf · 2012-01-04 20:31 · Score: 2
  
  Right. So I shouldn't store a massive many-user maildir on NTFS, and I shouldn't keep huge single-file datasets there either. Got it.
  But those are corner-cases, of which I'm sure there are some that ext2/3/4 falls down on as well: Ain't nothin' perfect.
  For common use, where there often aren't more than a few hundred smallish files in a directory or any one file exceeding a few gigabytes: What's the problem?
  And even then: If I push the envelope with NTFS and do those horrible, horrible things with it: What's the downside? Will performance simply be less than ideal, or will my cat spontaneously give birth to honest-to-god Gremlins who will incite the apocalypse?
  
  --
  Kid-proof tablet..
19. Re:Btrfs by RubberMallet · 2012-01-04 20:37 · Score: 2
  
  Ok, but the tree can go for a pout in a corner and you'll just get kernel panics on restart - this happened to me. No power outage, just a normal reboot and poof... it was repairable using the btrfs-zero-log tool.... but it wasn't a pleasant 10 minutes while I was thinking.. "What did I do, why why why did I think it was good to try out btrfs?" Of course once I got it booting again, I kept right on using btrfs :-) I love the snapshot thing... very useful
20. Re:Btrfs by DarkOx · 2012-01-05 00:51 · Score: 2
  
  Depends are we talking about the ordinary 'user' here or the ordinary "user of btrfs", which is pretty extraordinary when compared with the population of general PC users. A PRENDEND bug report that I would think might be useful would be:
  I have ~?TB volume composed of three drives each with a single partition of sizes X, Y, and Z. I have noticed that after I remove a snapshot really big files, in my case some VM images of size T, get corrupted, in that they seem to contain old data that would have been in the snap shot...
  Please find attached copies of the MBR from each disk, and the first 1024bytes from each partition. Let me know if I can provide anything else.
  -----------
  A bug report like that while does not likely contain the really specific details about file system structures (some of them might be in the attached data), does alter the devs to the fact there may be a problem and provides some information about how they might recreated it, so they can extract the data they really need. My guess is the typical btrfs user at this point is capable of creating such a bug report. As I don't think any teir1 distributions are using it as a default FS yet. So anyone with btrfs volume at least knows how run fdisk, dd, and use the btrfs progs.
  
  --
  Repeal the 17th Amendment TODAY! Also Please Read http://www.gnu.org/philosophy/right-to-read.html
21. Re:Btrfs by RemyBR · 2012-01-05 03:41 · Score: 2
  
  This.
  Don't know about this new version, but I tried btrfs on ubuntu a few months ago, on a box I use mostly with photo and video editing software. It was slow to the point of being completely unusable. Specially for non destructive photo editing, where the software creates and modifies (replaces) small files with metadata for each action you perform on the images. Have being using ext4 since then, and everything is ok.
  
  --
  Cosplayers.net - The Cosplayers Network
22. Re:Btrfs by ConceptJunkie · 2012-01-05 04:20 · Score: 2
  
  Well, the file system should be loosened so it can move about the whole partition. Otherwise you lose space.
  Besides, the defragmentation engine in NT, which was licensed from the folks who make Diskeeper, is extremely robust. I'm as much of a critic of Microsoft as they come; my opinion of Microsoft borders on hatred. But I've got nothing bad to say about NTFS other than to comment the need for constant defragging is a pain. But as far as robustness, in almost 20 years, I can honestly say I've almost never seen hard drive corruption with NTFS that wasn't associated with a hardware failure... and even when I wasn't sure, I'd give it the benefit of the doubt based on my experience. I don't ever recall seeing a power outage toast an NTFS partition. I'm not saying it's not possible, but I've used the NT line since 3.51 on many, many computers and since NTFS came along, it's one of the few things I have not felt the need to complain about.
  There are plenty of things to criticize Microsoft about, and I'm usually first in line to do so, but I really don't think NTFS is one place where they have failed.
  
  --
  You are in a maze of twisty little passages, all alike.
23. Re:Btrfs by ducman · 2012-01-05 04:42 · Score: 3, Interesting
  
  I MISS btrsf!
  I had a home server with 6TB of disk using btrfs and a second server with the same amount of disk, also using btrfs for backup. I had a power failure while the rsync backup was running, and both btrfs filesytems were mangled. I managed to recover most of the stuff after a couple days' worth of work, but I definitely changed back to xfs on LVM2.
  Btrfs was so much simpler, and I was able to maintain > 60 Mb/s write speeds to a set of crapy disks that only manage 12-14 Mb/s writes, now. I know I could RAID my disks to get back to those speeds, but with btrfs I was able to grow my server by replacing one disk at a time. With RAID and LVM2, it's not worth that much effort for a home media server.
  
  --
  "We have nothing in common, your attitude annoys me, and your political views are appalling."
24. Re:Btrfs by Anonymous Coward · 2012-01-05 06:43 · Score: 2
  
  Are you stinking nuts? Do you know how many programs depend on the stability of /dev/null? I would start with less important devices first (like the device you keep the Qt 4 dance on).
25. Re:Btrfs by NotBorg · 2012-01-05 06:59 · Score: 3, Informative
  
  It didn't happen in Fedora 16 as once planned but they're apparently going to make a go of it in Fedora 17: http://www.h-online.com/open/news/item/Btrfs-and-new-file-system-structure-agreed-for-Fedora-17-1389851.html
  Tick tick tick...
  
  --
  I want this account deleted.
Popcorn loaded, commence fanatical BS... by inflex · 2012-01-04 14:11 · Score: 4, Insightful

Waiting to see the usual fanatical wars over filesystems... people calling for the death of the EXT3/4 system.
Personally the whole fanatical thing seems a bit silly - who'd have ever thought that people would lynch each other over having different options for different purposes/tasks, the very core of the whole idea of what we do and strive for. I'm fine with ext4, thanks :)
1. Re:Popcorn loaded, commence fanatical BS... by RobbieThe1st · 2012-01-04 14:22 · Score: 2, Interesting
  
  I still say we should lynch EXT3/4(even though I use it) due to it's complete /inability/ to undelete files.
  Because, as we all know, people /never/ manage to accidentally delete files and /always/ have recent backups handy.
2. Re:Popcorn loaded, commence fanatical BS... by martin-boundary · 2012-01-04 14:24 · Score: 4, Funny
  
  Personally the whole fanatical thing seems a bit silly
  
  That's not silly! There are two reasons for silliness. Surprise and fear. Fear and surprise... and ruthless efficiency. There are *three* reasons for silliness, these being fear, surprise, and ruthless efficiency... and an almost fanatical devotion to the Pope. *Amongst* the reasons for silliness are such elements as fear, surprise, ruthless efficiency and ... Ok, you're right, fanatical is silly after all.
3. Re:Popcorn loaded, commence fanatical BS... by DarkOx · 2012-01-04 14:33 · Score: 4, Insightful
  
  Then what you should do is change you shell so rm is a functIon that moves stuff to the "trash" rather than compromise the on disk format of the file system so an operation "unlink" which is supposed to be destructive can be undone. Solve the problem in the correct place.
  
  --
  Repeal the 17th Amendment TODAY! Also Please Read http://www.gnu.org/philosophy/right-to-read.html
4. Re:Popcorn loaded, commence fanatical BS... by msk · 2012-01-04 14:58 · Score: 2
  
  Where'd you get fsck for btrfs?
5. Re:Popcorn loaded, commence fanatical BS... by MichaelSmith · 2012-01-04 15:02 · Score: 4, Funny
  
  I want a computer which lets me unsee certain image files.
  
  --
  http://michaelsmith.id.au
6. Re:Popcorn loaded, commence fanatical BS... by MightyYar · 2012-01-04 15:23 · Score: 2
  
  Agreed. I alias rm to 'rm -i' so that I have to at least type -f if I really mean it :)
  
  --
  W..w..W - Willy Waterloo washes Warren Wiggins who is washing Waldo Woo.
7. Re:Popcorn loaded, commence fanatical BS... by Daniel+Phillips · 2012-01-04 16:06 · Score: 2
  
  Ext4's only major flaw is that it does not have snapshots. That can be fixed, actually.
  
  --
  Have you got your LWN subscription yet?
8. Re:Popcorn loaded, commence fanatical BS... by Anonymous Coward · 2012-01-04 16:50 · Score: 2, Informative
  
  One workaround we did on our server over a decade ago was to hardlink basically everything to /shadow
  Entries in /shadow went through periodic timed deletes, but that avoided irreparable stupidity.
9. Re:Popcorn loaded, commence fanatical BS... by ILongForDarkness · 2012-01-04 17:24 · Score: 2
  
  And when your backup hasn't run yet what than? I've worked on 100+ TB of live data several PB of capacity systems. Sometimes users are dumping 10Gbps data to disk for days at a time. Than someone deletes something and woops the tape hasn't archived it yet. Admittedly a "recycle bin" probably wouldn't handle TBs of data but still scale the problem done and it is still a real issue. Downloaded a pdf and accidentally deleted it rather than the paper you just read. Oh crap and can't remember where it came from because you've clicked on 50 links between than and very useful links like http://something.com/alkshftfhY^asdlfkhalnlknlkrehwo aren't very helpful in finding out what the docs were. Seems trivial but anything that a user can see on a nearly daily basis isn't trivial it is a every day net positive feature to have.
10. Re:Popcorn loaded, commence fanatical BS... by ILongForDarkness · 2012-01-04 19:11 · Score: 2
  
  Nope doesn't wash. Sometimes you don't know what is important to you until someone else tells you its important. Like studying for exams and someone tells you oh you should look at that file again the prof said there will be a question on it on the exam, a book you finished reading you find out 3 weeks later someone else wants to read etc. It seems pretty ridiculous to me to assume that everyone will always only delete things that they will end up never needing in the future when no one knows the future, no one has perfect manual or mental dexterity to make sure that they don't accidentally hit enter after a typo, select the wrong folder etc. Shit happens that is why there is an undo button in word processors and that is why there should be an undo in the filesystem (or at least at the "presentation" layer (command processor, GUI etc)).
11. Re:Popcorn loaded, commence fanatical BS... by MemoryDragon · 2012-01-04 20:30 · Score: 2
  
  Why? The last time I had a look at BTRFs it was at least in a VM significantly slower than EXT4.
  This was noticable at every corner of the OS.
  I would not use it for production, at least not in a scenario where I/O performance matters, but the features are neat. I love
  the snapshotting. But my personal guess is it is at least a year away from being a viable EXT4 replacement.
Good stuff! by ickleberry · 2012-01-04 14:16 · Score: 5, Funny

I never did like the number "3.1" for some reason
1. Re:Good stuff! by Nursie · 2012-01-04 14:46 · Score: 5, Funny
  
  Maybe it's because we all know what comes next - 3.11, Linux for workgroups and then the dreaded Linux 95!
Wow by wbr1 · 2012-01-04 14:26 · Score: 2

The first kernel I compiled was 1.2.10, I know there are people who have here who have been it longer than I, so this is not an ego-trip. I just feel old. I need doctor Carol Marcus to make me .... "Feel young, as when the earth was new."

--
Silence is a state of mime.
1. Re:Wow by wbr1 · 2012-01-04 17:26 · Score: 3, Funny
  
  yep you're right.. no hair, no brains, no memory, no women.. life sucks!
  
  --
  Silence is a state of mime.
2. Re:Wow by rubycodez · 2012-01-04 17:43 · Score: 3, Funny
  
  I definitely still like women, I just can't remember why....
Re:I call bullshit. by Trepidity · 2012-01-04 14:38 · Score: 2

A 3.2-rc7 kernel is already in Debian's experimental repository fwiw.

--
10 PRINT CHR$(205.5+RND(1)); : GOTO 10
Re:Forgive my ignorance by Microlith · 2012-01-04 15:03 · Score: 2, Interesting

That was Ubuntu, as I recall, and not necessarily the greater kernel community. I'm sure they'd rather play it safe and have a slightly more power hungry but stable system than risk crashing people's systems because OEMs are incompetent and can't report their shit properly.
Re:Forgive my ignorance by mark_reh · 2012-01-04 17:26 · Score: 2

No, as I understand it, it is actually in the kernel. I think the problem was found in Ubuntu simply because it's the most popular (?) linux distro.
rm -i by steveha · 2012-01-04 17:54 · Score: 5, Insightful

I used to alias "rm" as "rm -i".
Then, one day, I was using someone else's computer. I used "rm" with the expectation that it would prompt me, but this person never bothered to set it up that way, and I had the fearful experience of worrying whether it was deleting too much. I hadn't been too careless that time, but it got me thinking. It's dangerous to use "rm" when I really mean "rm -i"; habits are strong things.
So I made a change that I still use. I now alias "r" as "rm -i". "r" by itself does not have default behavior on most computers. Now if I absent-mindedly type "r *.txt" on someone else's computer, I get "r: command not found" and I edit the command to say "rm -i".
I suppose I should have used "rmi" or something like that, just in case I am a guest somewhere that "r" was aliased to something crazy. In practice, it hasn't been a problem. I use more aliases than most people seem to; they seem to be content with the defaults. I seem to be the only one I know who likes one-letter aliases.
Hmm, I guess I might accidentally run the R statistics package someday?
steveha

--
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1. Re:rm -i by dotancohen · 2012-01-04 21:24 · Score: 4, Funny
  
  It's dangerous to use "rm" when I really mean "rm -i"; habits are strong things.
  Especially muscle-memory habits.:wq
  
  --
  It is dangerous to be right when the government is wrong.
2. Re:rm -i by lithis · 2012-01-05 02:13 · Score: 2
  
  Set HISTCONTROL to ignorespace. Then bash will not save any commands that begin with a space.
Re:Linux "fine security record" in 2011 (lol, NOT) by Ginger+Unicorn · 2012-01-04 23:29 · Score: 4, Funny

the fools... if only they'd used HOSTS FILES

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