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> Btrfs has been removed I'm still incredibly sad about that, especially as Btrfs has become a really solid filesystem over the last year or so in the upstream

> Btrfs has been removed I'm still incredibly sad about that, especially as Btrfs has become a really solid filesystem over the last year or so in the upstream kernel... Reference: https://access.redhat.com/documentation/en-us/red_hat_enterprise_linux/8-beta/html/8.0_beta_release_notes/removed_functionality#file_systems_and_storage_5 https://access.redhat.com/documentation/en-us/red_hat_enterp...

williamstein 8y ago
Indeed, Btrfs is uniquely capable and important. It has lightweight snapshots of directory trees, and fully supports NFS exports and kernel namespaces, so it can easily solve technical problems that currently can't be easily solved using ZFS or other filesystems. Btrfs is also used now for ChromeOS's Crostini Linux application container.
- SEJeff 8y ago
  bcachefs is another "competitor" to btrfs: https://bcachefs.org/ https://bcachefs.org/ But Redhat is going all in with stratis: https://stratis-storage.github.io/ https://stratis-storage.github.io/
- justizin 8y ago
  Notable: Btrfs is used for all of ChromeOS and the crostini container is just another volume. It's incredibly robust, really confusing why RH would be pulling this.
  - ams6110 8y ago
    It was never emphasized, and probably rarely used by their customers. Prior RHEL release used ext4, then xfs by default. People who run RHEL don't want to think about what filesystem to use. They want standard, stable, reliable -- not dozens of options and features.
    - Conan_Kudo 8y ago
      When you're pushing the container stuff, Btrfs becomes extraordinarily valuable. Being able to snapshot a base thing and then layer on top, and do trivial rebasing, as well as cheap replication of container volumes is _very_ useful. On my Fedora and EL7 systems, I use Btrfs for the OS and for my containers for those purposes. It's awesome.
  - smbarber 8y ago
    Slight correction: we use btrfs for the disk image backing the user's crostini state only. The rest of Chrome OS, and the crostini VM rootfs, still use ext4.
rwmj 8y ago
I know, that broke libguestfs too :-( Btrfs was the only Linux filesystem that let me create an 8 exabyte virtual filesystem in a reasonable time. https://rwmj.wordpress.com/2018/09/05/nbdkit-for-loopback-pt-5-8-exabyte-btrfs-filesystem/#content https://rwmj.wordpress.com/2018/09/05/nbdkit-for-loopback-pt...
- cwyers 8y ago
  What's the use case for an 8 exabyte virtual file system?
  - rwmj 8y ago
    Testing the limits :-) It's interesting because it shows you how things scale, and that information is useful even for normal-but-large filesystems. I've submitted a talk about this to FOSDEM next year.
ape4 8y ago
Previous Hacker News thread https://news.ycombinator.com/item?id=14907771 https://news.ycombinator.com/item?id=14907771
zeotroph 8y ago
Do they include other file systems which can provide data checksums? The linked stratis doesn't seem to have that feature, did they patch the underlying XFS? There don't seem to be that many filesystems with that capability yet: https://en.wikipedia.org/wiki/Comparison_of_file_systems#File_capabilities https://en.wikipedia.org/wiki/Comparison_of_file_systems#Fil...
- vetinari 8y ago
  No, they plan to implement dm-integrity target as one of available dm layers. See section 9.2.2 in https://stratis-storage.github.io/StratisSoftwareDesign.pdf https://stratis-storage.github.io/StratisSoftwareDesign.pdf
moonbug 8y ago
If it's only been "solid over the last year" it ain't solid.
langdon 8y ago
Really not an expert here but Red Hat did acquire and open source VDO from Permabit which has similar functionality AIUI.
- ofrzeta 8y ago
  As far as I know VDO only provides compression and deduplication. So no snapshots like in Btrfs and ZFS, although you can use LVM snapshots. Also no RAID features.
- Conan_Kudo 8y ago
  I use subvolumes, snapshots, and send/recv functionality for cheap replication of data. Sometimes even on RAIDed disks! There are only two file systems with that feature set today: Btrfs and ZFS. I personally prefer Btrfs because it's way more flexible and shipped with the Linux kernel.
ofrzeta 8y ago
I guess it depends on what Btrfs features you are using. I remember SUSE who are using Btrfs as a root fs in the enterprise distro restricting its use to a subset they consider stable. On the Btrfs status page https://btrfs.wiki.kernel.org/index.php/Status https://btrfs.wiki.kernel.org/index.php/Status you can see that the developers themselves consider several features "mostly ok", which is probably not an assessment most filesystem users will find reassuring.
- Conan_Kudo 8y ago
  I would actually be okay with Red Hat applying the same restriction SUSE did. For what it's worth, this is the feature set SUSE offers: https://www.suse.com/releasenotes/x86_64/SUSE-SLES/15/#TechInfo.Filesystems.Btrfs https://www.suse.com/releasenotes/x86_64/SUSE-SLES/15/#TechI... I would be absolutely okay if Red Hat applied the same restrictions.
  - fulafel 8y ago
    Has SuSE turned these off, or are they going to tell you "you shouldn't have used this feature" when you go for support?
    - Conan_Kudo 8y ago
      They are switched off. You can't use them. They patch btrfs-progs to prevent accessing those features.

williamstein 8y ago

Indeed, Btrfs is uniquely capable and important. It has lightweight snapshots of directory trees, and fully supports NFS exports and kernel namespaces, so it can easily solve technical problems that currently can't be easily solved using ZFS or other filesystems. Btrfs is also used now for ChromeOS's Crostini Linux application container.

SEJeff 8y ago
bcachefs is another "competitor" to btrfs: https://bcachefs.org/ https://bcachefs.org/ But Redhat is going all in with stratis: https://stratis-storage.github.io/ https://stratis-storage.github.io/
justizin 8y ago
Notable: Btrfs is used for all of ChromeOS and the crostini container is just another volume. It's incredibly robust, really confusing why RH would be pulling this.
- ams6110 8y ago
  It was never emphasized, and probably rarely used by their customers. Prior RHEL release used ext4, then xfs by default. People who run RHEL don't want to think about what filesystem to use. They want standard, stable, reliable -- not dozens of options and features.
  - Conan_Kudo 8y ago
    When you're pushing the container stuff, Btrfs becomes extraordinarily valuable. Being able to snapshot a base thing and then layer on top, and do trivial rebasing, as well as cheap replication of container volumes is _very_ useful. On my Fedora and EL7 systems, I use Btrfs for the OS and for my containers for those purposes. It's awesome.
- smbarber 8y ago
  Slight correction: we use btrfs for the disk image backing the user's crostini state only. The rest of Chrome OS, and the crostini VM rootfs, still use ext4.

rwmj 8y ago

I know, that broke libguestfs too :-( Btrfs was the only Linux filesystem that let me create an 8 exabyte virtual filesystem in a reasonable time. https://rwmj.wordpress.com/2018/09/05/nbdkit-for-loopback-pt-5-8-exabyte-btrfs-filesystem/#content https://rwmj.wordpress.com/2018/09/05/nbdkit-for-loopback-pt...

cwyers 8y ago
What's the use case for an 8 exabyte virtual file system?
- rwmj 8y ago
  Testing the limits :-) It's interesting because it shows you how things scale, and that information is useful even for normal-but-large filesystems. I've submitted a talk about this to FOSDEM next year.

ape4 8y ago

Previous Hacker News thread https://news.ycombinator.com/item?id=14907771 https://news.ycombinator.com/item?id=14907771

zeotroph 8y ago

Do they include other file systems which can provide data checksums? The linked stratis doesn't seem to have that feature, did they patch the underlying XFS? There don't seem to be that many filesystems with that capability yet: https://en.wikipedia.org/wiki/Comparison_of_file_systems#File_capabilities https://en.wikipedia.org/wiki/Comparison_of_file_systems#Fil...

vetinari 8y ago
No, they plan to implement dm-integrity target as one of available dm layers. See section 9.2.2 in https://stratis-storage.github.io/StratisSoftwareDesign.pdf https://stratis-storage.github.io/StratisSoftwareDesign.pdf

moonbug 8y ago

If it's only been "solid over the last year" it ain't solid.

langdon 8y ago

Really not an expert here but Red Hat did acquire and open source VDO from Permabit which has similar functionality AIUI.

ofrzeta 8y ago
As far as I know VDO only provides compression and deduplication. So no snapshots like in Btrfs and ZFS, although you can use LVM snapshots. Also no RAID features.
Conan_Kudo 8y ago
I use subvolumes, snapshots, and send/recv functionality for cheap replication of data. Sometimes even on RAIDed disks! There are only two file systems with that feature set today: Btrfs and ZFS. I personally prefer Btrfs because it's way more flexible and shipped with the Linux kernel.

ofrzeta 8y ago

I guess it depends on what Btrfs features you are using. I remember SUSE who are using Btrfs as a root fs in the enterprise distro restricting its use to a subset they consider stable. On the Btrfs status page https://btrfs.wiki.kernel.org/index.php/Status https://btrfs.wiki.kernel.org/index.php/Status you can see that the developers themselves consider several features "mostly ok", which is probably not an assessment most filesystem users will find reassuring.

Conan_Kudo 8y ago
I would actually be okay with Red Hat applying the same restriction SUSE did. For what it's worth, this is the feature set SUSE offers: https://www.suse.com/releasenotes/x86_64/SUSE-SLES/15/#TechInfo.Filesystems.Btrfs https://www.suse.com/releasenotes/x86_64/SUSE-SLES/15/#TechI... I would be absolutely okay if Red Hat applied the same restrictions.
- fulafel 8y ago
  Has SuSE turned these off, or are they going to tell you "you shouldn't have used this feature" when you go for support?
  - Conan_Kudo 8y ago
    They are switched off. You can't use them. They patch btrfs-progs to prevent accessing those features.