Linux filesystems was [Re: Debian cd supporting ext4.]
in [Debian]
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From: Sjoerd Hardeman on 28 Jul 2010 17:10 Op 28-07-10 21:34, Aniruddha schreef: > Agreed, it was hardly a double-blind randomized trial :) On a more > serious note: off course these tests don't prove anything. On the > other hand I have heard so many time that XFS can't handle a single > power failure without data corruption that I wanted to see for myself > what happens if you power off a pc. with an XFS filesystem. Apparently > not much. There might other problems hidden with XFS,just like ext3 ( > when copy pasting a home directory to another location I once lost the > whole directory due data corruption on ext3). As with all research, showing that something does not fail is notoriously hard. Showing that something fails given a specified set of circumstances, on the other hand, is dead easy. Yes, you did show that a poweroff does not destroy data. By the way, were you writing data? I think there's no filesystem that *can* fail when data is only being read, sort of hard disk failure of course... Sjoerd
From: Perry E. Metzger on 29 Jul 2010 10:10
On Wed, 28 Jul 2010 21:34:06 +0200 Aniruddha <mailingdotlist(a)gmail.com> wrote: > On Wed, Jul 28, 2010 at 9:09 PM, Perry E. Metzger > <perry(a)piermont.com> wrote: > > On Wed, 28 Jul 2010 14:46:29 +0200 Aniruddha > > <mailingdotlist(a)gmail.com> wrote: > >> I have done some testing with Debian stable in Virtualbox and I > >> have to say XFS works as advertised. I did power off the virtual > >> machine several times when working in Gnome / copying files. And > >> I did power off the virtual 5 times in a row when booting. > >> Nothing happened. Each time the virtual machine booted without > >> problems. > >> > >> I have to say, file system creating and file system checking is > >> lightning fast. I am very impressed. Next I'll test XFS on my > >> laptop. > > > > Although I have no reason to believe that XFS is flawed, your > > test is not proof of that. > > Agreed, it was hardly a double-blind randomized trial :) You make it sound like it was somehow useful if not entirely rigorous. In fact, the exercise showed virtually nothing at all. > On a more > serious note: off course these tests don't prove anything. On the > other hand I have heard so many time that XFS can't handle a single > power failure without data corruption that I wanted to see for > myself what happens if you power off a pc. And you haven't learned that even now, because virtual hardware does not behave enough like real hardware. For example, the virtual hardware does not simulate a modern disk cache at all, let alone the behavior of such a cache on a true power cut, so you would not see problems associated with the disk cache silently reordering writes and then failing to complete all of them on power failure. I would suggest avoiding making any pronouncements based on such "experiments". I have no reason to believe XFS has any problems at all, but your test did not demonstrate anything of value. Although most experienced users would dismiss your information as worthless, you might convince some people with insufficient knowledge that you had actually determined something and that they may make a decision on the basis of your experiments. -- Perry E. Metzger perry(a)piermont.com -- 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/20100729100305.122a87f5(a)jabberwock.cb.piermont.com |