Linux filesystems was [Re: Debian cd supporting ext4.]
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From: Lisi on 27 Jul 2010 03:30 On Tuesday 27 July 2010 08:10:15 Stan Hoeppner wrote: > XFS which is superior to all other Linux filesystems. Stan - Have you the time to give a rationale for this? I'm not in any way impugning your knowledge. But I am at the stage of accepting the default that Lenny gives me, for no better reason than that the developers chose it and it is there. It is time I understood better the reasons for each file system. (I gave up Reiserfs because Reiser murdered his wife - hardly a logical measure of how good his filesystem is!!) Lisi -- To UNSUBSCRIBE, email to debian-user-REQUEST(a)lists.debian.org with a subject of "unsubscribe". Trouble? Contact listmaster(a)lists.debian.org Archive: http://lists.debian.org/201007270823.05211.lisi.reisz(a)gmail.com
From: Aaron Toponce on 27 Jul 2010 11:50 On 7/27/2010 1:23 AM, Lisi wrote: > On Tuesday 27 July 2010 08:10:15 Stan Hoeppner wrote: >> XFS which is superior to all other Linux filesystems. > > Stan - > > Have you the time to give a rationale for this? Except XFS filesystems can't shrink, only grow. Sucks when you need to resize partitions/volumes, and they're all XFS. Further, XFS makes more system calls to the kernel than standard Ext2/3/4. Export an XFS filesystem on LVM over NFS, and you'll get a kernel oops on a 32-bit kernel. Trace it, and you'll see the plethora of nested system calls XFS makes. You won't oops with Ext2/3/4 in the same scenario. This can be mitigated by running a 64-bit system, if you have the hardware to do so. XFS has also had a history for randomly corrupting data. While this might have improved over time, I don't trust it. XFS does have dynamic inode allocation, and better data storage algorithms than the Ext-family. It's also a good performer, but Ext4 give XFS a run for its money. -- . O . O . O . . O O . . . O . . . O . O O O . O . O O . . O O O O . O . . O O O O . O O O
From: Stan Hoeppner on 27 Jul 2010 12:20 Volkan YAZICI put forth on 7/27/2010 8:22 AM: > You are missing a very important point: Durability to power failures. > (Excuse me, but a majority of GNU/Linux users are not switched to a UPS > or something.) And that's where XFS totally fails[1][2]. > [1] http://linux.derkeiler.com/Mailing-Lists/Debian/2008-11/msg00097.html 1. Never quote forum or email posts as empirical or reliable evidence of anything. They are opinion, unless they quote fact from reliable sources to back that opinion (which I did in my original post). There are of course exceptions to this rule of thumb, the main one being when the post is made by a developer who is a recognized authority on the piece of software being discussed. In the case of XFS this would be Dave Chinner, Alex Elder, Eric Sandeen, Christoph Hellwig, and others. In the case of EXT2/3/4 this would be Ted Tso, who happens, BTW, to work hand in hand with the XFS developers because they rely on each others patches to other parts of the Linux kernel. Not the last two entries: https://kerneltrap.org/mailarchive/linux-fsdevel/2010/7/16/expand In the case of Postfix this would be Wietse Venema and Viktor Duchovni. In the case of Linux this would be Linus Torvalds, Marcelo Tosatti, Alan Cox, Andrew Morton and others. Etc. 2. If you are going to quote opinions from unreliable sources, at least read the entire thread before quoting it. In this case, again, your source contradicts what you state, and then, oddly, himself: "PS. Apparently they've improved some power-failure problems with XFS since I used it, but then they also said that *before* I started using it so I can't say I'd put any trust in that." Aneurin Price admits he is aware of new changes that fix the problem, but then discounts the fact and gives an anecdotal story as to why the fix isn't really a fix. > [2] http://xfs.org/index.php/XFS_FAQ#Q:_Why_do_I_see_binary_NULLS_in_some_files_after_recovery_when_I_unplugged_the_power.3F You didn't even read the information you linked to, which contradicts what you state: The fix for this issue has been in mainline since May 2007, over 3 years ago. "Q: Why do I see binary NULLS in some files after recovery when I unplugged the power? Update: This issue has been addressed with a CVS fix on the 29th March 2007 and merged into mainline on 8th May 2007 for 2.6.22-rc1." > And considering > my personal experiences, reiserfs is the fastest fs (among ext3 and xfs) > in terms of boot recovery phase times. So, given that XFS recovery of any size filesystem is less than one second, reiserfs recovery is so much less than 1 second that you notice the difference? From: http://www.enterprisenetworkingplanet.com/netos/article.php/623661/XFS-Its-worth-the-wait.htm "XFS also provides file system journaling. This means that XFS uses database recovery techniques to recover a consistent file system state after a system crash. Using journaling, XFS is able to accomplish this recovery in under a second, regardless of the file system size." > [1] http://linux.derkeiler.com/Mailing-Lists/Debian/2008-11/msg00097.html Here you quoted misinformation, because the opinions were based on experience the OPs had with the software before it was patched to fix the problem, i.e. more than 3 years ago. You treated this as empirical evidence in your argument against XFS. I have shown this to be incorrect. > [2] http://xfs.org/index.php/XFS_FAQ#Q:_Why_do_I_see_binary_NULLS_in_some_files_after_recovery_when_I_unplugged_the_power.3F You quoted this FAQ item solely based on the tile, without reading it, in your effort to denounce XFS. The article clearly states the problem was fixed over 3 years ago, which you conveniently ignored. >From now on, please get your facts straight, with proper documentation, before trying to denounce a fantastic piece of FOSS into which many top-of-their-game kernel engineers have put tens of thousands of man hours, striving to make it the best it can be--and are wildly succeeding. Join the xfs mailing list and you might learn something useful in place of this trash you're talking about it. Better yet, read what Hans Reiser had to say about XFS. He was totally enamored with it, and wanted to duplicate many of its features: http://www.osnews.com/story/69 Hans Reiser: "XFS is an excellent file system, and there is an important area where XFS is higher performance than we are...ReiserFS does a complete tree traversal for every 4k block it writes, and then it inserts one pointer at a time into the tree, which means that every 4k write incurs the overhead of a balancing of the tree (which means it moves data around). For this reason, XFS has better very large file performance...If you want to stream multi-media data for Hollywood style applications, or use ACLs now rather than wait for Reiser4, you might want to use XFS." "This is an area we are still experimenting with. We currently do what ext2 does, and preallocate blocks. What XFS does is much better, they allocate blocknrs to blocks at the time they are flushed to disk, and this allows a much more efficient and optimal allocation to occur. We knew we couldn't do it the XFS way...but reiser4 is being built around delayed allocation, and I'd like to thank the XFS developers for taking the time to personally explain to me why delayed allocation is the way to go." -- Stan -- To UNSUBSCRIBE, email to debian-user-REQUEST(a)lists.debian.org with a subject of "unsubscribe". Trouble? Contact listmaster(a)lists.debian.org Archive: http://lists.debian.org/4C4F0705.2050005(a)hardwarefreak.com
From: Lisi on 27 Jul 2010 12:40 On Tuesday 27 July 2010 09:51:53 Stan Hoeppner wrote: > Lisi put forth on 7/27/2010 2:23 AM: > > On Tuesday 27 July 2010 08:10:15 Stan Hoeppner wrote: > >> XFS which is superior to all other Linux filesystems. > > > > Stan - > > > > Have you the time to give a rationale for this? > > Sure. Thanks, Stan, for a lucid and erudite exposition. Much appreciated. Lisi -- To UNSUBSCRIBE, email to debian-user-REQUEST(a)lists.debian.org with a subject of "unsubscribe". Trouble? Contact listmaster(a)lists.debian.org Archive: http://lists.debian.org/201007271731.34069.lisi.reisz(a)gmail.com
From: Stan Hoeppner on 27 Jul 2010 13:20
Aaron Toponce put forth on 7/27/2010 10:41 AM: > XFS has also had a history for randomly corrupting data. While this > might have improved over time, I don't trust it. Can you cite or reference anything to back your claim? Time frame? Irix or Linux? Serious users reported this or casual/hobbyist users? If this was ever the case the situation could not have lasted long before patches fixed it. Have you seen SGI's customer list and the size of the systems and storage they run with nothing but XFS? For instance, NAS has over 1.4PB of XFS filesystems, 1PB CXFS and over 400TB XFS: http://www.nas.nasa.gov/Resources/Systems/columbia.html http://www.nas.nasa.gov/Resources/Systems/archive_storage.html NASA trusts it with over 1PB of storage, but _you_ don't trust it? Who are you again? How many hundreds of TB of storage do you manage on EXT3/4? ;) -- Stan -- To UNSUBSCRIBE, email to debian-user-REQUEST(a)lists.debian.org with a subject of "unsubscribe". Trouble? Contact listmaster(a)lists.debian.org Archive: http://lists.debian.org/4C4F1551.8010109(a)hardwarefreak.com |