Messages in this thread | | | From | Thomas Fjellstrom <> | Subject | Re: [linux-pm] Massive ext4 filesystem corruption after a failed s2disk/ram cycle | Date | Sat, 7 Nov 2009 15:22:41 -0700 |
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On Thu November 5 2009, Henrique de Moraes Holschuh wrote: > On Wed, 04 Nov 2009, KOSAKI Motohiro wrote: > > > On Wed, Oct 07, 2009 at 01:14:10PM +1100, Daniel Pittman wrote: > > > > For what it is worth, I would also be quite interested to know > > > > /why/ XFS is bad in this regard. Is it just the previously stated > > > > "XFS writes to disk despite freezing kernel threads" issue, or > > > > something deeper? > > > > > > sync pushes out all data to disk, but in a journaling filesystem that > > > might just but the log not the "normal" place on disk. For a boot > > > loader to deal with it properly it actually needs to do an replay of > > > the log. Grub does so for reiserfs but not for XFS for some reason. > > > I don't know why problems don't trigger more often with ext3, though. > > > > I'm sorry for the long delayed and offtopic responce. I discussed this > > issue with okuji-san (GRUB2 maintainer) at several month ago. > > He really wish linux implement real sync. > > This is not about real sync. It is about the box being able to reboot > after a crash or power failure. > > GRUB2 is broken in that regard, at least in its peecee-BIOS version: > last time I checked, it doesn't sort RAID components so that it won't > boot from failed or out-of-sync older components, it can't deal with > some of the filesystems being unclean... > > > A bootloader has much constraint than OS (mainly caused by size > > constraint). it can't implemnt jornal log replay logic for _all_ > > filesystem. Why can't we implement storong sync syscall? I don't think > > this is PM nor bootloader fault. > > A bootloader that can't boot a system that went through an unclean > shutdown is quite broken. >
It can barely boot a system that's gone through a clean shutdown. "bios read error" and all that.
-- Thomas Fjellstrom tfjellstrom@shaw.ca
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