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Safe Data > Features.
Between choosing to have a file system that is much more reliable on shitty (aka commodity) hardware vs having mount-time quota scanning I'll choose the safer FS.
Ext4 to be standard for Fedora 11, Btrfs also included (heise online)
Posted Jan 23, 2009 23:10 UTC (Fri) by dlang (✭ supporter ✭, #313)
if you are thinking that XFS requires systems with special power supplies, that is a myth, and that bog that was fixed in may 2007 (linked to elsewhere in this topic) was the fix for it.
if anything, the fact that ext3 ignores write barriers by default while XFS honors them would make me say that XFS is safer on commodity hardware :-)
Posted Jan 24, 2009 1:49 UTC (Sat) by i3839 (guest, #31386)
Depends. If it ignores write barriers because it is reliable without them in some other way, then it's not less safe. Similarly, if some drives ignore write barriers, then not counting on them in the fs is more reliable as well.
Posted Jan 24, 2009 2:21 UTC (Sat) by dlang (✭ supporter ✭, #313)
I think you will find arguments where Ted Tso is arguing that they need to be on for data safety and Andrew says that it's unacceptable to introduce the performance regression that would result from doing so.
Posted Jan 26, 2009 20:29 UTC (Mon) by zlynx (subscriber, #2285)
Note all the generally and usually qualifiers in there.
I recall reading about Ext3 journal corruption issues when the power fails as the journal is wrapping around, because the drive writes the end of the journal, some data, then back to the beginning of the journal instead of writing end of the journal, start of the journal, some data.
Posted Jan 29, 2009 16:47 UTC (Thu) by anton (guest, #25547)
Also, why should writing to the journal first be safer than writing
the other stuff first? With meta-data journaling as typically used in
ext3 this would lead to typical meta-data
Actually the data=ordered mode writes the data before the
corresponding journal entries to prevent that from happening. So if
the disks then write the journal entries before the data thanks to
write-caching disks without barriers, that subverts the safety
data=ordered provides. If the disks write stuff out-of-order in other
ways, other failure modes are possible.
I guess that the reason we don't see lots of reports of data
destroyed by ext3 without barriers is that most people don't have lots
of write traffic going on (but then they won't notice any performance
penalty from barriers either), and you expect to lose the file you
write when the system dies anyway.
Posted Jan 25, 2009 19:29 UTC (Sun) by Nelson (subscriber, #21712)
The big difference between the ext(x) family and XFS and JFS is ext(x) seem to be supported, really well. The others are still kind of bolt-ons to various distributions. I ran an all XFS Mandrake/Mandriva and Fedora systems for years, you'd be shocked how many times you'd' install a kernel upgrade and have a non-bootable system. I got to the point I'd never even consider doing a full distribution upgrade. The situation might be better now but for a very long time it looked like just a handful of kernel devs so much as cared about XFS, let alone enhanced it and kept it fresh with the rest of the kernel.
Posted Jan 25, 2009 20:35 UTC (Sun) by cantsin (guest, #4420)
Posted Jan 25, 2009 20:39 UTC (Sun) by jengelh (subscriber, #33263)
Posted Jan 26, 2009 2:25 UTC (Mon) by salimma (subscriber, #34460)
Posted Jan 25, 2009 23:56 UTC (Sun) by nix (subscriber, #2304)
However, I'm afraid I consider 'files you were writing right now might be
chewed up' to be a *lot* better than 'files you were writing right now
might be chewed up, oh, and so might anything else on your disk, even if
you haven't touched it for months'.
I too saw this behaviour when I used XFS (years ago now): I've never seen
it using ext2 or ext3, even when I had multiple consecutive power cuts
during a lightning storm, even when I had bad RAM on the machine and was
doing massive cross-filesystem renames. Of course this too is 'anecdotal':
all reports from third parties are necessarily anecdotal. I don't see how
this makes them invalid (if they come from multiple sources).
Posted Jan 26, 2009 23:44 UTC (Mon) by lmb (subscriber, #39048)
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