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Ages ago XFS had a rather nasty behavior in case of power failure - any files opened for write would be deleted after restart. From what I remember this was by

by marwis 3y ago

Ages ago XFS had a rather nasty behavior in case of power failure - any files opened for write would be deleted after restart. From what I remember this was by design. Has this changed?

chasil 3y ago
I think that is because the hardware did not enforce write barriers.
- jleahy 3y ago
  No, it happens with a proper RAID controller also, but is now fixed as I mentioned separately.
Tor3 3y ago
What you describe was common on the SGI systems we used at work. Some setups had a configuration file which was constantly written to and read from, and that file would be (most of the time) empty if there was a power failure (I don't btw know why the SGI systems didn't have a power-failure-emergency-shutdown mode, the power supplies kept power for several seconds. But anyway). However: This _never_ happened with XFS on Linux systems. Exact same software. I don't know why. But XFS has been incredibly stable for not only my personal boxes but also for everything we have provided to customers at work. We need non-varying sustained write rates for huge amounts of data, and XFS is smooth, much better than when tested against e.g. ext4 (the tests we did were done years ago, we haven't retested as XFS just works.
- jleahy 3y ago
  I’ve run XFS at scale and I’ve seen exactly this behaviour (files open for writing becoming truncated after power loss). However it was definitively fixed in a kernel update about 5-10 years ago. I haven’t seen it since.
hulitu 3y ago
I stayed away from XFS because it had another bad behaviour: after a crash it will do a replay of the log and happily continue. After a couple of crashes the filesystem became so corrupted that even the replay of the log failed and fsck was useless. I tried also the option of running fsck after every crash but this also did not help (some crashes seems to mess up the filesystem badly). At the end i stayed with JFS ( which i was also testing at that time together with Reiserfs) because it was the best balance between speed and CPU power at that time.

by marwis 3y ago

Ages ago XFS had a rather nasty behavior in case of power failure - any files opened for write would be deleted after restart. From what I remember this was by design. Has this changed?

chasil 3y ago

I think that is because the hardware did not enforce write barriers.

jleahy 3y ago
No, it happens with a proper RAID controller also, but is now fixed as I mentioned separately.

Tor3 3y ago

What you describe was common on the SGI systems we used at work. Some setups had a configuration file which was constantly written to and read from, and that file would be (most of the time) empty if there was a power failure (I don't btw know why the SGI systems didn't have a power-failure-emergency-shutdown mode, the power supplies kept power for several seconds. But anyway). However: This _never_ happened with XFS on Linux systems. Exact same software. I don't know why. But XFS has been incredibly stable for not only my personal boxes but also for everything we have provided to customers at work. We need non-varying sustained write rates for huge amounts of data, and XFS is smooth, much better than when tested against e.g. ext4 (the tests we did were done years ago, we haven't retested as XFS just works.

jleahy 3y ago
I’ve run XFS at scale and I’ve seen exactly this behaviour (files open for writing becoming truncated after power loss). However it was definitively fixed in a kernel update about 5-10 years ago. I haven’t seen it since.

hulitu 3y ago

I stayed away from XFS because it had another bad behaviour: after a crash it will do a replay of the log and happily continue. After a couple of crashes the filesystem became so corrupted that even the replay of the log failed and fsck was useless. I tried also the option of running fsck after every crash but this also did not help (some crashes seems to mess up the filesystem badly). At the end i stayed with JFS ( which i was also testing at that time together with Reiserfs) because it was the best balance between speed and CPU power at that time.