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> There are no (stable) alternatives. BTRFS certainly not, as it's "under heavy development"¹ (since... forever). Note that they don't mean "it's unstable," ju

> There are no (stable) alternatives. BTRFS certainly not, as it's "under heavy development"¹ (since... forever). Note that they don't mean "it's unstable," just "there are significant improvements between versions." Most importantly: > The filesystem disk format is stable; this means it is not expected to change unless there are very strong reasons to do so. If there is a format change, filesystems which implement the previous disk format will continue to be mountable and usable by newer kernels. ...and only _new features_ are expected to stabilise: > As with all software, newly added features may need a few releases to stabilize. So overall, at least as far as their own claims go, this is not "heavy development" as in "don't use."

disordinary 7y ago
There's differing opinions of BTRFS's suitability in production - it's the default filesystem of SUSE on one hand, on the other RedHat has deprecated BTRFS support because they see it as not being production ready and they don't see it being production ready in the near future. They also feel that the more legacy linux filesystems have added features to compete.
- m4rtink 7y ago
  Check what features of BTRFS SUSE actually uses and considers supported/supportable.
- kalleboo 7y ago
  It's also the default file system of millions of Synology NASes running in consumer hands (although Synology shimmed on their own RAID5/6 support)
  - mehhh 7y ago
    Kroger (and their subsidiaries like QFC, Fred Meyer, Fry's Marketplace, etc), Walmart, Safeway (and Albertsons/Randalls) all use Suse with BTRFS for their point of sale systems.
  - vetinari 7y ago
    Synology uses standard linux md (for btrfs too). Even SHR (Synology Hybrid RAID) is just different partitions on the drive allocated to different volumes, so you can use mixed-capacity drives effectively.
    - kalleboo 7y ago
      Right, instead of BTRFS RAID5/6, they use Linux md raid, but I believe they have custom patches to BTRFS to "punch through" information from md, so that when BTRFS has a checksum mismatch it can use the md raid mirror disk for repair.
- jauer 7y ago
  Facebook runs on btrfs: https://facebookmicrosites.github.io/btrfs/docs/btrfs-facebook.html https://facebookmicrosites.github.io/btrfs/docs/btrfs-facebo...
  - m-ueberall 7y ago
    But then, your personal requirements/use cases might not be the same as Facebook's. (And this does not only apply to Btrfs[1]/ZFS, it also applies to GlusterFS, use of specific hardware, ...) [1] which I used for nearly two years on a small desktop machine on a daily basis; ended up with (minor?) errors on the file system that could not be repaired and decided to switch to ZFS. No regrets, nor similar errors since.
HorstG 7y ago
Some features such as Raid5 were still firmly in "don't use if you value your data" territory last I looked. So it is important to be informed as to what can be used and what might be more dangerous with btrfs
- berti 7y ago
  Keep in mind that RAID5 isn’t feasible with multi-TB disks (the probability of failed blocks when rebuilding the array is far too high). That said, RAID6 also suffers the same write-hole problem with Btrfs. Personally I choose RAIDZ2 instead.
  - metaphor 7y ago
    To be sure, it's entirely feasible, just not prudent with today's typical disk capacities.
    - Godel_unicode 7y ago
      Feasible is different than possible, and carries a strong connotation of being suitable/able to be done successfully. Many things are possible, many of those things are not feasible.
  - XelNika 7y ago
    > Keep in mind that RAID5 isn’t feasible with multi-TB disks (the probability of failed blocks when rebuilding the array is far too high). What makes you say that? I've seen plenty of people make this claim based on URE rates, but I've also not seen any evidence that it is a real problem for a 3-4 drive setup. Modern drives are specced at 1 URE per 10^15 bits read (or better), so less than 1 URE in 125 TB read. Even if a rebuild did fail, you could just start over from a backup. Sure, if the array is mission critical and you have the money, use something with more redundancy, but I don't think RAID5 is infeasible in general.
    - bleuarff 7y ago
      Last time I checked (a few years ago I must say), a 10^15 URE was only for enteprise-grade drives and not for consumer-level, where most drives have a 10^14 URE. Which means your build is almost guaranteed to fail on a large-ish raid setup. So yeah, RAID is still feasible with multi-TB disks if you have the money to buy disks with the appropriate reliability. For the common folk, raid is effectively dead with today's disk sizes.

disordinary 7y ago

There's differing opinions of BTRFS's suitability in production - it's the default filesystem of SUSE on one hand, on the other RedHat has deprecated BTRFS support because they see it as not being production ready and they don't see it being production ready in the near future. They also feel that the more legacy linux filesystems have added features to compete.

m4rtink 7y ago
Check what features of BTRFS SUSE actually uses and considers supported/supportable.
kalleboo 7y ago
It's also the default file system of millions of Synology NASes running in consumer hands (although Synology shimmed on their own RAID5/6 support)
- mehhh 7y ago
  Kroger (and their subsidiaries like QFC, Fred Meyer, Fry's Marketplace, etc), Walmart, Safeway (and Albertsons/Randalls) all use Suse with BTRFS for their point of sale systems.
- vetinari 7y ago
  Synology uses standard linux md (for btrfs too). Even SHR (Synology Hybrid RAID) is just different partitions on the drive allocated to different volumes, so you can use mixed-capacity drives effectively.
  - kalleboo 7y ago
    Right, instead of BTRFS RAID5/6, they use Linux md raid, but I believe they have custom patches to BTRFS to "punch through" information from md, so that when BTRFS has a checksum mismatch it can use the md raid mirror disk for repair.
jauer 7y ago
Facebook runs on btrfs: https://facebookmicrosites.github.io/btrfs/docs/btrfs-facebook.html https://facebookmicrosites.github.io/btrfs/docs/btrfs-facebo...
- m-ueberall 7y ago
  But then, your personal requirements/use cases might not be the same as Facebook's. (And this does not only apply to Btrfs[1]/ZFS, it also applies to GlusterFS, use of specific hardware, ...) [1] which I used for nearly two years on a small desktop machine on a daily basis; ended up with (minor?) errors on the file system that could not be repaired and decided to switch to ZFS. No regrets, nor similar errors since.

HorstG 7y ago

Some features such as Raid5 were still firmly in "don't use if you value your data" territory last I looked. So it is important to be informed as to what can be used and what might be more dangerous with btrfs

berti 7y ago
Keep in mind that RAID5 isn’t feasible with multi-TB disks (the probability of failed blocks when rebuilding the array is far too high). That said, RAID6 also suffers the same write-hole problem with Btrfs. Personally I choose RAIDZ2 instead.
- metaphor 7y ago
  To be sure, it's entirely feasible, just not prudent with today's typical disk capacities.
  - Godel_unicode 7y ago
    Feasible is different than possible, and carries a strong connotation of being suitable/able to be done successfully. Many things are possible, many of those things are not feasible.
- XelNika 7y ago
  > Keep in mind that RAID5 isn’t feasible with multi-TB disks (the probability of failed blocks when rebuilding the array is far too high). What makes you say that? I've seen plenty of people make this claim based on URE rates, but I've also not seen any evidence that it is a real problem for a 3-4 drive setup. Modern drives are specced at 1 URE per 10^15 bits read (or better), so less than 1 URE in 125 TB read. Even if a rebuild did fail, you could just start over from a backup. Sure, if the array is mission critical and you have the money, use something with more redundancy, but I don't think RAID5 is infeasible in general.
  - bleuarff 7y ago
    Last time I checked (a few years ago I must say), a 10^15 URE was only for enteprise-grade drives and not for consumer-level, where most drives have a 10^14 URE. Which means your build is almost guaranteed to fail on a large-ish raid setup. So yeah, RAID is still feasible with multi-TB disks if you have the money to buy disks with the appropriate reliability. For the common folk, raid is effectively dead with today's disk sizes.