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Funnily enough, XFS is the only file system on Linux where I've lost data. Back in the day, the wisdom was to stay away from it if you were in an iffy power sit

by arjie 9y ago

Funnily enough, XFS is the only file system on Linux where I've lost data. Back in the day, the wisdom was to stay away from it if you were in an iffy power situation because it would serve zeroes if there was a write to a file near a power loss (I.e. you wouldn't get old file or new file but something else) Having had that happen to me I always used some extN and didn't lose any existing files. Of course that's a decade or more ago and I may be misremembering but a cursory Google looks like other people encountered something like it too.

crest 9y ago
Afaik the problem is that XFS trusts the hardware to do the right thing during a power loss aka stop inflight requests before the brownout turns you disks and their controllers into heavily biased random number generators. Lots of x86(-64) hardware lacks a proper power loss interrupt triggered early enough to stop the all I/O in time. The ext3 journaling hides that problem to some extend by journaling more than just the minimal metadata required.
- msla 9y ago
  Then XFS isn't suitable for consumer-grade hardware.
linsomniac 9y ago
For maybe 3-6 months a decade ago I was running XFS on my laptop. My laptop had some sort of flakiness, ISTR it was graphics related, and it would require frequent reboots for a while. I remember one particular instance where after a power cycle a file I was working on an hour prior to it was trashed. That was a real "Oh FFS!" moment and I stopped using XFS. But, I will say I've had a lot of success using XFS to serve images, particularly tiles. Particularly map tiles that are generated once and then basically static. There it has a lot less overhead when formatted with size=2048, so lots of small files are handled better. Of course, reiserfs was even better, but part of that was with a job I worked on where they just blindly rendered map tiles for the whole earth, and so there were a lot of 50 byte solid blue tiles. Reiser did really well with that, though some deduplication or linking would have been a huge benefit.

by arjie 9y ago

crest 9y ago

Afaik the problem is that XFS trusts the hardware to do the right thing during a power loss aka stop inflight requests before the brownout turns you disks and their controllers into heavily biased random number generators. Lots of x86(-64) hardware lacks a proper power loss interrupt triggered early enough to stop the all I/O in time. The ext3 journaling hides that problem to some extend by journaling more than just the minimal metadata required.

msla 9y ago
Then XFS isn't suitable for consumer-grade hardware.

linsomniac 9y ago

For maybe 3-6 months a decade ago I was running XFS on my laptop. My laptop had some sort of flakiness, ISTR it was graphics related, and it would require frequent reboots for a while. I remember one particular instance where after a power cycle a file I was working on an hour prior to it was trashed. That was a real "Oh FFS!" moment and I stopped using XFS. But, I will say I've had a lot of success using XFS to serve images, particularly tiles. Particularly map tiles that are generated once and then basically static. There it has a lot less overhead when formatted with size=2048, so lots of small files are handled better. Of course, reiserfs was even better, but part of that was with a job I worked on where they just blindly rendered map tiles for the whole earth, and so there were a lot of 50 byte solid blue tiles. Reiser did really well with that, though some deduplication or linking would have been a huge benefit.