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Btrfs has experienced some data loss bugs in recent memory. It looks like ZFS is the only remaining option. https://www.phoronix.com/scan.php?page=news_item&px

by nayuki 10y ago

Btrfs has experienced some data loss bugs in recent memory. It looks like ZFS is the only remaining option. https://www.phoronix.com/scan.php?page=news_item&px=Btrfs-Data-Bug-Hole-Read-Comp https://www.phoronix.com/scan.php?page=news_item&px=Btrfs-Da... https://www.spinics.net/lists/linux-btrfs/msg59190.html https://www.spinics.net/lists/linux-btrfs/msg59190.html https://www.mail-archive.com/linux-btrfs@vger.kernel.org/msg55161.html https://www.mail-archive.com/linux-btrfs@vger.kernel.org/msg...

seiferteric 10y ago
Yes I have tried to use btrfs several times for work projects and personally because I was very excited about it but every time I have ran into severe bugs even though it was said to be "stable". I have given up for now, maybe I will check back in a couple more years.
- djsumdog 10y ago
  The last time I was using btrfs was around 2014, and I was wondering why my hard drive was always showing 100% utilization even after I moved/deleted a ton-o-stuff. Turns out at the time, re-balancing still had to be run manually. I'm not sure if that still holds true.
  - delroth 10y ago
    It is still a problem, I just had one of my personal servers hit issues where I couldn't even manually re-balance because the metadata was full. Had to apply weird workarounds to be able to write to that filesystem again...
- Dylan16807 10y ago
  I really like btrfs for my backup machine, but it sometimes manages to hang when it's cleaning up deleted snapshots. This is a problem that's much worse when on a hard drive or fragmented file system, but I've gotten it to happen even on a recently-balanced drive with a small amount of snapshots. I recently had a server be crippled by running snapper on default settings for a few months. And after a couple days of balancing (which desperately needs a throttle control) it wasn't much better, so I gave up on having it run btrfs. I think the record I managed was slightly over two minutes of btrfs blocking all disk I/O. Something is deeply wrong with how it organizes transactions.
- dom0 10y ago
  Funny, my btrfs story is somewhat similar. I don't hit severe bugs, though, just severe performance issues. E.g. btrfs on / always sooner or later means for me that the entire IO to the disk that's on will be _thrashed_ during system updates or package installs / uninstalls.
tombrossman 10y ago
Any idea if ZFS plays well with Ubuntu's full-disk encryption? I've used the FDE option at install for years and every time I upgrade (I wipe & reinstall every year or so) I try to understand how to first set up ZFS, then FDE, and then I realize it's far too complicated for me. Any good tutorials or setup guides that even a moron could understand? I've got a pretty good setup now with a fairly complex fstab, multiple SSDs, backup drives, and everything fully encrypted and auto mounting at boot. I'd really love to move this to a file system more resistant to data corruption.
- nisa 10y ago
  You can always use zvols and just use ext4+luks on that. There is also work on ZFS native encryption that looks pretty promising, not sure if it's ready yet.
- benley 10y ago
  I haven't tried to do it with Ubuntu specifically, but I do know that ZFS-on-linux works fine atop LUKS full-disk encryption. My laptop is running NixOS with such a setup, and I'm pretty sure I followed the Ubuntu ZFS documentation while figuring out how to do it. (summary: I don't know how to make it super easy, but what you want should totally work)
- drvdevd 10y ago
  I use it all over with LUKS on Ubuntu. It works fine, but there's one little hitch: when calling anything that ultimately calls grub-probe (e.g. apt-get upgrade), you have to symlink the decrypted device mapper volume up a layer into /dev because grub-probe can't seem to find the ZFS vdev(s) otherwise. ie: "ln -s /dev/mapper/encrypted-zfs-vdev /dev". This is in fact the case on every Linux distribution I've run ZFS over dm-crypt on. EDIT: IOW its a grub bug not an Ubuntu bug.
  - XorNot 10y ago
    The other problem I've found is that grub's update-grub scripts do not handle mirrored ZFS volumes well at all - they wind up just spraying doubled up invalid commands everywhere even up to yakkety so far. I've had it on my backlog to at some point go in and sort out my initramfs's insanity when it comes to handling crypt'd disks in general - it should be a lot less brittle then it is.

by nayuki 10y ago

seiferteric 10y ago

Yes I have tried to use btrfs several times for work projects and personally because I was very excited about it but every time I have ran into severe bugs even though it was said to be "stable". I have given up for now, maybe I will check back in a couple more years.

djsumdog 10y ago
The last time I was using btrfs was around 2014, and I was wondering why my hard drive was always showing 100% utilization even after I moved/deleted a ton-o-stuff. Turns out at the time, re-balancing still had to be run manually. I'm not sure if that still holds true.
- delroth 10y ago
  It is still a problem, I just had one of my personal servers hit issues where I couldn't even manually re-balance because the metadata was full. Had to apply weird workarounds to be able to write to that filesystem again...
Dylan16807 10y ago
I really like btrfs for my backup machine, but it sometimes manages to hang when it's cleaning up deleted snapshots. This is a problem that's much worse when on a hard drive or fragmented file system, but I've gotten it to happen even on a recently-balanced drive with a small amount of snapshots. I recently had a server be crippled by running snapper on default settings for a few months. And after a couple days of balancing (which desperately needs a throttle control) it wasn't much better, so I gave up on having it run btrfs. I think the record I managed was slightly over two minutes of btrfs blocking all disk I/O. Something is deeply wrong with how it organizes transactions.
dom0 10y ago
Funny, my btrfs story is somewhat similar. I don't hit severe bugs, though, just severe performance issues. E.g. btrfs on / always sooner or later means for me that the entire IO to the disk that's on will be _thrashed_ during system updates or package installs / uninstalls.

tombrossman 10y ago

Any idea if ZFS plays well with Ubuntu's full-disk encryption? I've used the FDE option at install for years and every time I upgrade (I wipe & reinstall every year or so) I try to understand how to first set up ZFS, then FDE, and then I realize it's far too complicated for me. Any good tutorials or setup guides that even a moron could understand? I've got a pretty good setup now with a fairly complex fstab, multiple SSDs, backup drives, and everything fully encrypted and auto mounting at boot. I'd really love to move this to a file system more resistant to data corruption.

nisa 10y ago
You can always use zvols and just use ext4+luks on that. There is also work on ZFS native encryption that looks pretty promising, not sure if it's ready yet.
benley 10y ago
I haven't tried to do it with Ubuntu specifically, but I do know that ZFS-on-linux works fine atop LUKS full-disk encryption. My laptop is running NixOS with such a setup, and I'm pretty sure I followed the Ubuntu ZFS documentation while figuring out how to do it. (summary: I don't know how to make it super easy, but what you want should totally work)
drvdevd 10y ago
I use it all over with LUKS on Ubuntu. It works fine, but there's one little hitch: when calling anything that ultimately calls grub-probe (e.g. apt-get upgrade), you have to symlink the decrypted device mapper volume up a layer into /dev because grub-probe can't seem to find the ZFS vdev(s) otherwise. ie: "ln -s /dev/mapper/encrypted-zfs-vdev /dev". This is in fact the case on every Linux distribution I've run ZFS over dm-crypt on. EDIT: IOW its a grub bug not an Ubuntu bug.
- XorNot 10y ago
  The other problem I've found is that grub's update-grub scripts do not handle mirrored ZFS volumes well at all - they wind up just spraying doubled up invalid commands everywhere even up to yakkety so far. I've had it on my backlog to at some point go in and sort out my initramfs's insanity when it comes to handling crypt'd disks in general - it should be a lot less brittle then it is.