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I’ve heard it lacks maturity and of a few cases of data corruption. Those cases are no doubt outdated now, but I haven’t heard any news to sway me that BTRFS is

I’ve heard it lacks maturity and of a few cases of data corruption. Those cases are no doubt outdated now, but I haven’t heard any news to sway me that BTRFS is ready for prime time. Ditto for ZFS btw.

xkfiebfifbek 3y ago
this. that said, lots of people do. arch and gentoo default install instructions suggest it just fine, telling you the pros and cons over ext4
LeoSolaris 3y ago
ZFS is stable and solid. It's hold up is licensing. ZFS isn't licensed in a way that can be included in the Linux kernel distribution. Plus, my understanding is that Linus Torvalds has a dislike of ZFS because it came from Sun Microsystems.
- xcdzvyn 3y ago
  What problem did Linus have with Sun? Oracle I understand, but Sun? Was it something to do with UNIX?
  - stametseater 3y ago
    I haven't heard of him objecting to the Sun origins of ZFS, but he has warned people away from ZFS on the grounds of Oracle's litigious reputation: > And honestly, there is no way I can merge any of the ZFS efforts until I get an official letter from Oracle that is signed by their main legal counsel or preferably by Larry Ellison himself that says that yes, it's ok to do so and treat the end result as GPL'd. > Other people think it can be ok to merge ZFS code into the kernel and that the module interface makes it ok, and that's their decision. But considering Oracle's litigious nature, and the questions over licensing, there's no way I can feel safe in ever doing so. > And I'm not at all interested in some "ZFS shim layer" thing either that some people seem to think would isolate the two projects. That adds no value to our side, and given Oracle's interface copyright suits (see Java), I don't think it's any real licensing win either. > Don't use ZFS. It's that simple. It was always more of a buzzword than anything else, I feel, and the licensing issues just make it a non-starter for me.
    - ianai 3y ago
      Could GPL be amended to be compatible with ZFS? Something along the lines of a legal shim. (Clearly Linus already said no to this in extension.)
      - deleted 3y ago
        [deleted]
      - stametseater 3y ago
        In principle I guess, but not in practice. Linux is distributed under the GPLv2 without the "or later" clause, so you couldn't simply convince the FSF to release a GPLv4 that allowed this. Nor do contributors sign away their rights. To re-license the kernel you'd have to get the consent of all the contributors, or replace the parts for which that was impossible.
theandrewbailey 3y ago
Facebook was deploying BTRFS 5 years ago.[0] I haven't heard that they've changed or had any data corruption issues. In fact, they've integrated zstd compression into BTRFS. [0] https://engineering.fb.com/2018/10/30/open-source/linux/ https://engineering.fb.com/2018/10/30/open-source/linux/
- toast0 3y ago
  Facebook runs servers a lot different than a home oriented distro is likely to be run. I was there through aquisition from late 2014 to late 2019, and I mostly avoided production operations in FB land. I don't remember hearing about any power failures --- either UPS and transfer switches all worked 100%, node replacement covered any issues 100%, or I just wasn't in the loop. This isn't common at home; most people have at least a few brief power blips every once in a while, and those with many often get a UPS, but home grade UPSes often fail. I'd expect at least one unexpected power failure per 3 years in a home environment. Most of FB production is built from ephemeral containers. If a container host crashes and restarts and the filesystem is corrupt, the container would be rescheduled somewhere else, and the host would be sent for repair (reimaging) automagically, and a product team like mine would not really know unless they really looked, maybe just that the container moved. That's not realistic for home users. The containers themselves were short lived for many reasons. I'd estimate most of them lived for less than a month. A home user distro install often lasts much longer. That said, I don't remember seeing disk corruption, but I do remember a series of issues where we couldn't write to disk because it was full, with disk usage of maybe 60%. As I recall, there was only one couple week period where that happened. This was resolved in the moment by replacing affected containers with new ones on other hosts, and permanently by a fix in the host kernels; broken filesystems were not fixed, they were abandoned. This isn't great for home users either. There was a separate class of operations for persistent data storage; although there was work to containerize that as well, I had little visibility. Persistent storage machines were different and I don't know if they used btrfs or not. This all doesn't mean it's not a good filesystem for home users, just that Facebook's endorsement doesn't transfer as the use case is much different.
mvanbaak 3y ago
> Ditto for ZFS btw This is untrue. ZFS is ready for prime time. The problem here is that it is licensed under a license that is not compatible with the GPL, so it will never be imported into the kernel. Because it's an external module, most distros dont offer it in their installer etc. If you want zfs, you can either install it during install in expert mode, or go BSD where it is a first class FS
- dymk 3y ago
  apt install zfs works just fine though? I’ve set it up in Debian many times in minutes, am I missing something?
  - zokier 3y ago
    On debian zfs is available only as dkms, and from contrib repo insted of main
  - mvanbaak 3y ago
    Yeah, like I said, after you installed it, it's available. As mentioned here, it's also not in the main repo.
znpy 3y ago
zfs is way simpler to manage than btrfs. also, there does not seem to be a proper guide to btrfs. only random of bits and bytes here and there. zfs on the other hand is very well documented.
- _piif 3y ago
  > zfs is way simpler to manage than btrfs Not sure I agree. On ZFS I have to worry about an out of tree kernel module and all the implications of that, extra things like setting the correct ashift, making sure the recordsize is tuned individually in datasets to not destroy performance for specific worksets, ensuring ARC doesn't cause OOM behavior with applications which allocate a lot of memory at once (since it doesn't use the page cache), etc etc. With BTRFS however off the top of my head the only thing I remember doing was making sure nodatacow was set for subvolumes containing databases and VM disks. You are absolutely correct about the ZFS ecosystem containing superior tooling however.

xkfiebfifbek 3y ago

this. that said, lots of people do. arch and gentoo default install instructions suggest it just fine, telling you the pros and cons over ext4

LeoSolaris 3y ago

ZFS is stable and solid. It's hold up is licensing. ZFS isn't licensed in a way that can be included in the Linux kernel distribution. Plus, my understanding is that Linus Torvalds has a dislike of ZFS because it came from Sun Microsystems.

xcdzvyn 3y ago
What problem did Linus have with Sun? Oracle I understand, but Sun? Was it something to do with UNIX?
- stametseater 3y ago
  I haven't heard of him objecting to the Sun origins of ZFS, but he has warned people away from ZFS on the grounds of Oracle's litigious reputation: > And honestly, there is no way I can merge any of the ZFS efforts until I get an official letter from Oracle that is signed by their main legal counsel or preferably by Larry Ellison himself that says that yes, it's ok to do so and treat the end result as GPL'd. > Other people think it can be ok to merge ZFS code into the kernel and that the module interface makes it ok, and that's their decision. But considering Oracle's litigious nature, and the questions over licensing, there's no way I can feel safe in ever doing so. > And I'm not at all interested in some "ZFS shim layer" thing either that some people seem to think would isolate the two projects. That adds no value to our side, and given Oracle's interface copyright suits (see Java), I don't think it's any real licensing win either. > Don't use ZFS. It's that simple. It was always more of a buzzword than anything else, I feel, and the licensing issues just make it a non-starter for me.
  - ianai 3y ago
    Could GPL be amended to be compatible with ZFS? Something along the lines of a legal shim. (Clearly Linus already said no to this in extension.)
    - deleted 3y ago
      [deleted]
    - stametseater 3y ago
      In principle I guess, but not in practice. Linux is distributed under the GPLv2 without the "or later" clause, so you couldn't simply convince the FSF to release a GPLv4 that allowed this. Nor do contributors sign away their rights. To re-license the kernel you'd have to get the consent of all the contributors, or replace the parts for which that was impossible.

theandrewbailey 3y ago

Facebook was deploying BTRFS 5 years ago.[0] I haven't heard that they've changed or had any data corruption issues. In fact, they've integrated zstd compression into BTRFS. [0] https://engineering.fb.com/2018/10/30/open-source/linux/ https://engineering.fb.com/2018/10/30/open-source/linux/

toast0 3y ago
Facebook runs servers a lot different than a home oriented distro is likely to be run. I was there through aquisition from late 2014 to late 2019, and I mostly avoided production operations in FB land. I don't remember hearing about any power failures --- either UPS and transfer switches all worked 100%, node replacement covered any issues 100%, or I just wasn't in the loop. This isn't common at home; most people have at least a few brief power blips every once in a while, and those with many often get a UPS, but home grade UPSes often fail. I'd expect at least one unexpected power failure per 3 years in a home environment. Most of FB production is built from ephemeral containers. If a container host crashes and restarts and the filesystem is corrupt, the container would be rescheduled somewhere else, and the host would be sent for repair (reimaging) automagically, and a product team like mine would not really know unless they really looked, maybe just that the container moved. That's not realistic for home users. The containers themselves were short lived for many reasons. I'd estimate most of them lived for less than a month. A home user distro install often lasts much longer. That said, I don't remember seeing disk corruption, but I do remember a series of issues where we couldn't write to disk because it was full, with disk usage of maybe 60%. As I recall, there was only one couple week period where that happened. This was resolved in the moment by replacing affected containers with new ones on other hosts, and permanently by a fix in the host kernels; broken filesystems were not fixed, they were abandoned. This isn't great for home users either. There was a separate class of operations for persistent data storage; although there was work to containerize that as well, I had little visibility. Persistent storage machines were different and I don't know if they used btrfs or not. This all doesn't mean it's not a good filesystem for home users, just that Facebook's endorsement doesn't transfer as the use case is much different.

mvanbaak 3y ago

> Ditto for ZFS btw This is untrue. ZFS is ready for prime time. The problem here is that it is licensed under a license that is not compatible with the GPL, so it will never be imported into the kernel. Because it's an external module, most distros dont offer it in their installer etc. If you want zfs, you can either install it during install in expert mode, or go BSD where it is a first class FS

dymk 3y ago
apt install zfs works just fine though? I’ve set it up in Debian many times in minutes, am I missing something?
- zokier 3y ago
  On debian zfs is available only as dkms, and from contrib repo insted of main
- mvanbaak 3y ago
  Yeah, like I said, after you installed it, it's available. As mentioned here, it's also not in the main repo.

znpy 3y ago

zfs is way simpler to manage than btrfs. also, there does not seem to be a proper guide to btrfs. only random of bits and bytes here and there. zfs on the other hand is very well documented.

_piif 3y ago
> zfs is way simpler to manage than btrfs Not sure I agree. On ZFS I have to worry about an out of tree kernel module and all the implications of that, extra things like setting the correct ashift, making sure the recordsize is tuned individually in datasets to not destroy performance for specific worksets, ensuring ARC doesn't cause OOM behavior with applications which allocate a lot of memory at once (since it doesn't use the page cache), etc etc. With BTRFS however off the top of my head the only thing I remember doing was making sure nodatacow was set for subvolumes containing databases and VM disks. You are absolutely correct about the ZFS ecosystem containing superior tooling however.