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"Flagship"? I don't know a single person who uses it in production systems. It's the only filesystem I've lost data to. Ditto for friends. Please go look up su

"Flagship"? I don't know a single person who uses it in production systems. It's the only filesystem I've lost data to. Ditto for friends. Please go look up survivor bias. That's what all you btrfs fanboys don't seem to understand. It doesn't matter how well it has worked for 99.9% of you. Filesystems have to be the most reliable component in an operating system. It's a flagship whose fsck requires you to contact developers to seek advice on how to use it because otherwise it might destroy your filesystem. It's a flagship whose userspace tools, fifteen years in, are still seeing major changes. It's a flagship whose design is so poor that fifteen years in the developers are making major changes to its structure and depreciating old features in ways that do not trigger an automatic upgrade or informative error to upgrade, but cause the filesystem to panic with error messages for which there is no documentation and little clue what the problem is. No other filesystem has these issues.

jchw 2y ago
Btrfs is in production all over the damn place, at big corporations and all kinds of different deployments. Synology has their own btrfs setup that they ship to customers with their NAS software for example. I found it incredibly annoying the first time I ran out of disk space on btrfs, but many of these points are hyperbolic and honestly just silly. For example, btrfs doesn't really do offline fsck. fsck.btrfs has a zero percent chance of destroying your volume because it does nothing. As for the user space utilities changing... I'm not sure how that demonstrates the filesystem is not production ready. Personally I usually use either XFS or btrfs as my root filesystem. While I've caught some snags with btrfs, I've never lost any data. I don't actually know anyone who has, I've merely just heard about it. And it's not like other well-regarded filesystems have never ran into data loss situations: even OpenZFS recently (about a year ago) uncovered a data-eating bug that called its reliability into question. I'm sure some people will angrily tell me that actually btrfs is shit and the worst thing to ever be created and honestly whatever. I am not passionate about filesystems. Wake me up when there's a better one and it's mainlined. Maybe it will eventually be bcachefs. (Edit: and just to be clear, I do realize bcachefs is mainline and Kent Overstreet considers it to be stable and safe. However, it's still young and it's upstream future has been called into question. For non-technical reasons, but still; it does make me less confident.)
- aaronmdjones 2y ago
  For example, btrfs doesn't really do offline fsck. fsck.btrfs has a zero percent chance of destroying your volume because it does nothing. fsck.btrfs does indeed do nothing, but that's not the tool they were complaining about. From the btrfs-check(8) manpage: Warning Do not use --repair unless you are advised to do so by a developer or an experienced user, and then only after having accepted that no fsck can successfully repair all types of filesystem corruption. E.g. some other software or hardware bugs can fatally damage a volume. [...] DANGEROUS OPTIONS --repair enable the repair mode and attempt to fix problems where possible Note there’s a warning and 10 second delay when this option is run without --force to give users a chance to think twice before running repair, the warnings in documentation have shown to be insufficient
  - jchw 2y ago
    Yes, but that doesn't do the job that a fsck implementation does. fsck is something you stuff into your initrd to do some quick checks/repairs prior to mounting, but btrfs intentionally doesn't need those. If you need btrfs-check, you have probably hit either a catastrophic bug or hardware failure. This is not the same as fsck for some other filesystems. However, ZFS is designed the same way and also has no fsck utility. So whatever point was intended to be made was not, in any case.
- shiroiushi 2y ago
  >I don't actually know anyone who has, I've merely just heard about it. Well "yarg", a few comments up in this conversation, says he lost all his data to it with the last year. I've seen enough comments like that that I don't see it as a trustworthy filesystem. I never see comments like that about ext4 or ZFS.
  - jchw 2y ago
    Contrary to popular belief, people on a forum you happen to participate in are still just strangers. In line with popular belief, anecdotal evidence is not a good basis to form an opinion.
stuaxo 2y ago
I list data on btrfs on a raspberry pi with a slightly dodgy PSU. We need more testing of filesystems and pulling the power. I switched to a NAS with battery backup and it's been better. So that was inconclusive, before that the last time I lost data like that was to Reiserfs in the early 2000s.
danudey 2y ago
I agree with what you say, and I would never trust btrfs with my data because of issues that I've seen in the past, My last job I installed my Ubuntu desktop with btrfs and within three days it had been corrupted so badly because of a power outage that I had to completely wipe and reinstall the system. That said: > but cause the filesystem to panic with error messages for which there is no documentation and little clue what the problem is. The one and only time I experimented with ZFS as a root filesystem I got bit in the ass because the zfs tools one day added a new feature flag to the filesystem that the boot loader (grub) didn't understand and therefore it refused to read the filesystem, even read-only. Real kick in the teeth, that one, especially since the feature flag was completely irrelevant to just reading enough of the filesystem for the boot loader to load the kernel and there was no way to override it without patching grub's zfs module on another system then porting it over. Aside from that, ZFS has been fantastic, and now that we're all using UEFI and our kernels and initrds are on FAT32 filesystems I'm much less worried, but I'm still a bit gunshy. Not as much as with BTRFS, mind you, but somewhat.
cmurf 2y ago
Meta (Facebook) has millions of instances of Btrfs in production. More than any other filesystem by far. A few years ago when Fedora desktop variants started using Btrfs by default, Meta’s experience showed it was no less reliable than ext4 or XFS.
eru 2y ago
> Please go look up survivor bias. That's what all you btrfs fanboys don't seem to understand. It doesn't matter how well it has worked for 99.9% of you. Filesystems have to be the most reliable component in an operating system. Not sure. It's useful if they are reliable, but they only need to be roughly as reliable as your storage media. If your storage media breaks down once in a thousand years (or once a year for a thousand disks), then it doesn't matter much if your filesystem breaks down once in a million years or once in a trillion years. That being said, I had some trouble with BTRFS.

jchw 2y ago

Btrfs is in production all over the damn place, at big corporations and all kinds of different deployments. Synology has their own btrfs setup that they ship to customers with their NAS software for example. I found it incredibly annoying the first time I ran out of disk space on btrfs, but many of these points are hyperbolic and honestly just silly. For example, btrfs doesn't really do offline fsck. fsck.btrfs has a zero percent chance of destroying your volume because it does nothing. As for the user space utilities changing... I'm not sure how that demonstrates the filesystem is not production ready. Personally I usually use either XFS or btrfs as my root filesystem. While I've caught some snags with btrfs, I've never lost any data. I don't actually know anyone who has, I've merely just heard about it. And it's not like other well-regarded filesystems have never ran into data loss situations: even OpenZFS recently (about a year ago) uncovered a data-eating bug that called its reliability into question. I'm sure some people will angrily tell me that actually btrfs is shit and the worst thing to ever be created and honestly whatever. I am not passionate about filesystems. Wake me up when there's a better one and it's mainlined. Maybe it will eventually be bcachefs. (Edit: and just to be clear, I do realize bcachefs is mainline and Kent Overstreet considers it to be stable and safe. However, it's still young and it's upstream future has been called into question. For non-technical reasons, but still; it does make me less confident.)

aaronmdjones 2y ago
For example, btrfs doesn't really do offline fsck. fsck.btrfs has a zero percent chance of destroying your volume because it does nothing. fsck.btrfs does indeed do nothing, but that's not the tool they were complaining about. From the btrfs-check(8) manpage: Warning Do not use --repair unless you are advised to do so by a developer or an experienced user, and then only after having accepted that no fsck can successfully repair all types of filesystem corruption. E.g. some other software or hardware bugs can fatally damage a volume. [...] DANGEROUS OPTIONS --repair enable the repair mode and attempt to fix problems where possible Note there’s a warning and 10 second delay when this option is run without --force to give users a chance to think twice before running repair, the warnings in documentation have shown to be insufficient
- jchw 2y ago
  Yes, but that doesn't do the job that a fsck implementation does. fsck is something you stuff into your initrd to do some quick checks/repairs prior to mounting, but btrfs intentionally doesn't need those. If you need btrfs-check, you have probably hit either a catastrophic bug or hardware failure. This is not the same as fsck for some other filesystems. However, ZFS is designed the same way and also has no fsck utility. So whatever point was intended to be made was not, in any case.
shiroiushi 2y ago
>I don't actually know anyone who has, I've merely just heard about it. Well "yarg", a few comments up in this conversation, says he lost all his data to it with the last year. I've seen enough comments like that that I don't see it as a trustworthy filesystem. I never see comments like that about ext4 or ZFS.
- jchw 2y ago
  Contrary to popular belief, people on a forum you happen to participate in are still just strangers. In line with popular belief, anecdotal evidence is not a good basis to form an opinion.

stuaxo 2y ago

I list data on btrfs on a raspberry pi with a slightly dodgy PSU. We need more testing of filesystems and pulling the power. I switched to a NAS with battery backup and it's been better. So that was inconclusive, before that the last time I lost data like that was to Reiserfs in the early 2000s.

danudey 2y ago

I agree with what you say, and I would never trust btrfs with my data because of issues that I've seen in the past, My last job I installed my Ubuntu desktop with btrfs and within three days it had been corrupted so badly because of a power outage that I had to completely wipe and reinstall the system. That said: > but cause the filesystem to panic with error messages for which there is no documentation and little clue what the problem is. The one and only time I experimented with ZFS as a root filesystem I got bit in the ass because the zfs tools one day added a new feature flag to the filesystem that the boot loader (grub) didn't understand and therefore it refused to read the filesystem, even read-only. Real kick in the teeth, that one, especially since the feature flag was completely irrelevant to just reading enough of the filesystem for the boot loader to load the kernel and there was no way to override it without patching grub's zfs module on another system then porting it over. Aside from that, ZFS has been fantastic, and now that we're all using UEFI and our kernels and initrds are on FAT32 filesystems I'm much less worried, but I'm still a bit gunshy. Not as much as with BTRFS, mind you, but somewhat.

cmurf 2y ago

Meta (Facebook) has millions of instances of Btrfs in production. More than any other filesystem by far. A few years ago when Fedora desktop variants started using Btrfs by default, Meta’s experience showed it was no less reliable than ext4 or XFS.

eru 2y ago

> Please go look up survivor bias. That's what all you btrfs fanboys don't seem to understand. It doesn't matter how well it has worked for 99.9% of you. Filesystems have to be the most reliable component in an operating system. Not sure. It's useful if they are reliable, but they only need to be roughly as reliable as your storage media. If your storage media breaks down once in a thousand years (or once a year for a thousand disks), then it doesn't matter much if your filesystem breaks down once in a million years or once in a trillion years. That being said, I had some trouble with BTRFS.