Filesystems (ext3, reiser, xfs, jfs) comparison on Debian Etch (Debian Administration) [LWN.net]

Filesystems (ext3, reiser, xfs, jfs) comparison on Debian Etch (Debian Administration)

Posted Apr 27, 2006 17:16 UTC (Thu) by hch (guest, #5625)
In reply to: Filesystems (ext3, reiser, xfs, jfs) comparison on Debian Etch (Debian Administration) by Seegras
Parent article: Filesystems (ext3, reiser, xfs, jfs) comparison on Debian Etch (Debian Administration)

The problem is not ATA disks but an enabled disk write cache [1].

When the disk write cache is enabled you lose the cache content when power fails. That's a problem with any journaling filesystem because it can't guarantee integrity.
From reports this seems worse for XFS then for other filesystems. This might be somewhat of a false positive though, as XFS does the most strict filesystem consistency tests at runtime and barfs out at the smallest inconsistancy, while the other filesystems do weaker checks and rely on fsck.
These days it shouldn't be a problem anymore, as the journaling filesystems support write barriers that make disk write caches safe to use.

[1] which kinda makes this an ATA problem again. SCSI disks beeing for enterprise/serious use disable the write cache by default, ATA disks OTOH traditionally enable it by default to get much better benchmark results.

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