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Wed, 16 Jan 2008

Filesystems and disk caches.

It is known that disk caches are generally very bad for data integrity in case of various hardware failures or power outages.
It looks like even the most safe filesystem will have hard time recovering in such cases.

Alan Cox describes how Ext3 behaves in such situation: if powerfail during write damages the sector, ext3 can not recover; powerfail during write may cause random numbers to be returned on read, buf fsck should handle that; ext3 should survive if powerfail damages some sectors around sector which was written. All above does not happen always and bad things can happen in every case.
XFS have even more serious damage in case of powerfail.

/devel/fs :: Link / Comments (0)