8 ms·

bcachefs should be heavily supported, it doesn't get nearly enough for what it supposes to do: https://www.patreon.com/bcachefs https://www.patreon.com/bcachefs

by liuliu 7y ago

uep 7y ago
I've been looking forward to using bcachefs as I had a few bad experiences with btrfs. Is bcachefs more-or-less ready for some use cases now? Does it still support caching layers like bcache did?
- zaarn 7y ago
  To my knowledge, caching layers are supported but require some setup and don't have much documentation to setup rn. If all you need is a simple root FS that is CoW and checksummed, bcachefs works pretty good, in my experience. I've been using it productively as a root and home FS for about two years or so.
- ZoomZoomZoom 7y ago
  It's quite usable, but of course, do not trust it with your unique unbacked-up data yet. I use it as a main FS for a desktop workstation and I'm pretty happy with it. Waiting impatiently for EC to be implemented for efficient pooling of multiple devices. Regarding caching: "Bcachefs allows you to specify disks (or groups thereof) to be used for three categories of I/O: foreground, background, and promote. Foreground devices accept writes, whose data is copied to background devices asynchronously, and the hot subset of which is copied to the promote devices for performance."
cookiecaper 7y ago
Honestly just use ZFS. We've wasted enough effort over obscure licensing minutia.
- admax88q 7y ago
  > We've wasted enough effort over obscure licensing minutia. Which was precisely Sun/Oracle's goal when they released ZFS under the purposefully GPL incompatible CDDL. Sun was hoping to make OpenSolaris the next Linux whilst ensuring that no code from OpenSolaris could be moved back to linux. I can't think of another plausible reason why they would write a new open source license for their open source operating system and making such a license incompatible with the GPL.
  - ilikejam 7y ago
    There were genuine reasons for the CDDL - it wasn't an anti-gpl thing. https://www.youtube.com/watch?v=-zRN7XLCRhc&feature=youtu.be&t=1375 https://www.youtube.com/watch?v=-zRN7XLCRhc&feature=youtu.be...
    - morning_gelato 7y ago
      Danese Cooper, one of the people at Sun who helped create the CDDL, responded in the comment section of that very video: Lovely except it really was decided to explicitly make OpenSolaris incompatible with GPL. That was one of the design points of the CDDL. I was in that room, Bryan and you were not, but I know its fun to re-write history to suit your current politics. I pleaded with Sun to use a BSD family license or the GPL itself and they would consider neither because that would have allowed D-Trace to end up in Linux. You can claim otherwise all you want...this was the truth in 2005.
      - ilikejam 7y ago
        I stand corrected!
      - toyg 7y ago
        Yeah, it's hard to understand this without context. Sun saw D-Trace and ZFS as the differentiators of Solaris from Linux, a massive competitive advantage that they simply could not (and would not) relinquish. Opensourcing was a tactical move, they were not going to give away their crown jewels with it. The whole open-source steer by SUN was a very disingenous strategy, forced by the changed landscape in order to try and salvage some parvence of relevance. Most people saw right through it, which is why SUN ended up as it did shortly thereafter: broke, acquired, and dismantled.
- quantummkv 7y ago
  > Honestly just use ZFS. We've wasted enough effort over obscure licensing minutia. I am willing to bet that Google had the same thought. And I am also willing to bet that Google is regretting that thought now.
- chc 7y ago
  I don't think something that is the subject of an ongoing multi-billion-dollar lawsuit can rightly be called "obscure licensing minutia." It is high-profile and its actual effects have proven pretty significant.
- Dylan16807 7y ago
  It's not just licensing. ZFS has some deep-rooted flaws that can only be solved by block pointer rewrite, something that has an ETA of "maybe eventually".
  - macdice 7y ago
    Care to elaborate?
    - Dylan16807 7y ago
      You can't make a copy-on-write copy of a file. You can't deduplicate existing files, or existing snapshots. You can't defragment. You can't remove devices from a pool. That last one is likely to get some kind of hacky workaround. But nobody wants to do the invasive changes necessary for actual BPR to enable that entire list.
      - ColanR 7y ago
        Wow. As a casual user - someone who at one point was trying to choose between RAID, LVM and ZFS for an old NAS - some of those limitations of ZFS seem pretty basic. I would have taken it for granted that I could remove a device from a pool or defragment.
ac29 7y ago
Many of the advanced features aren't implemented yet though, like compression, encryption, snapshots, RAID5/6....
- jeltz 7y ago
  Compression and encryption have been implemented, but not snapshots and RAID5/6.
- mschuster91 7y ago
  why would you want to embed raid5/6 in the filesystem layer? Linux has battle-tested mdraid for this, I'm not going to trust a new filesystem's own implementation over it. Same for encryption, there are already existing crypto layers both on the block and filesystem (as an overlay) level.
  - wheybags 7y ago
    Because the FS can be deeply integrated with the RAID implementation. With a normal RAID, if the data at some address is different between the two disks, there's no way for the fs to tell which is correct, because the RAID code essentially just picks one, it can't even see the other. With ZFS for example, there is a checksum stored with the data, so when you read, zfs will check the data on both and pick the correct one. It will also overwrite the incorrect version with the correct one, and log the error. It's the same kind of story with encryption, if its built in you can do things like incremental backups of an encrypted drive, without ever decrypting it on the target.
    - vetinari 7y ago
      > With a normal RAID, if the data at some address is different between the two disks, there's no way for the fs to tell which is correct, because the RAID code essentially just picks one, it can't even see the other. That's problem only with RAID1, only when copies=2 (granted, most often used case) and only when the underlying device cannot report which sector has gone bad.
    - notacoward 7y ago

bcachefs should be heavily supported, it doesn't get nearly enough for what it supposes to do: https://www.patreon.com/bcachefs https://www.patreon.com/bcachefs

by liuliu 7y ago

bcachefs should be heavily supported, it doesn't get nearly enough for what it supposes to do: https://www.patreon.com/bcachefs https://www.patreon.com/bcachefs

uep 7y ago

I've been looking forward to using bcachefs as I had a few bad experiences with btrfs. Is bcachefs more-or-less ready for some use cases now? Does it still support caching layers like bcache did?

zaarn 7y ago
To my knowledge, caching layers are supported but require some setup and don't have much documentation to setup rn. If all you need is a simple root FS that is CoW and checksummed, bcachefs works pretty good, in my experience. I've been using it productively as a root and home FS for about two years or so.
ZoomZoomZoom 7y ago
It's quite usable, but of course, do not trust it with your unique unbacked-up data yet. I use it as a main FS for a desktop workstation and I'm pretty happy with it. Waiting impatiently for EC to be implemented for efficient pooling of multiple devices. Regarding caching: "Bcachefs allows you to specify disks (or groups thereof) to be used for three categories of I/O: foreground, background, and promote. Foreground devices accept writes, whose data is copied to background devices asynchronously, and the hot subset of which is copied to the promote devices for performance."

cookiecaper 7y ago

Honestly just use ZFS. We've wasted enough effort over obscure licensing minutia.

admax88q 7y ago
> We've wasted enough effort over obscure licensing minutia. Which was precisely Sun/Oracle's goal when they released ZFS under the purposefully GPL incompatible CDDL. Sun was hoping to make OpenSolaris the next Linux whilst ensuring that no code from OpenSolaris could be moved back to linux. I can't think of another plausible reason why they would write a new open source license for their open source operating system and making such a license incompatible with the GPL.
- ilikejam 7y ago
  There were genuine reasons for the CDDL - it wasn't an anti-gpl thing. https://www.youtube.com/watch?v=-zRN7XLCRhc&feature=youtu.be&t=1375 https://www.youtube.com/watch?v=-zRN7XLCRhc&feature=youtu.be...
  - morning_gelato 7y ago
    Danese Cooper, one of the people at Sun who helped create the CDDL, responded in the comment section of that very video: Lovely except it really was decided to explicitly make OpenSolaris incompatible with GPL. That was one of the design points of the CDDL. I was in that room, Bryan and you were not, but I know its fun to re-write history to suit your current politics. I pleaded with Sun to use a BSD family license or the GPL itself and they would consider neither because that would have allowed D-Trace to end up in Linux. You can claim otherwise all you want...this was the truth in 2005.
    - ilikejam 7y ago
      I stand corrected!
    - toyg 7y ago
      Yeah, it's hard to understand this without context. Sun saw D-Trace and ZFS as the differentiators of Solaris from Linux, a massive competitive advantage that they simply could not (and would not) relinquish. Opensourcing was a tactical move, they were not going to give away their crown jewels with it. The whole open-source steer by SUN was a very disingenous strategy, forced by the changed landscape in order to try and salvage some parvence of relevance. Most people saw right through it, which is why SUN ended up as it did shortly thereafter: broke, acquired, and dismantled.
quantummkv 7y ago
> Honestly just use ZFS. We've wasted enough effort over obscure licensing minutia. I am willing to bet that Google had the same thought. And I am also willing to bet that Google is regretting that thought now.
chc 7y ago
I don't think something that is the subject of an ongoing multi-billion-dollar lawsuit can rightly be called "obscure licensing minutia." It is high-profile and its actual effects have proven pretty significant.
Dylan16807 7y ago
It's not just licensing. ZFS has some deep-rooted flaws that can only be solved by block pointer rewrite, something that has an ETA of "maybe eventually".
- macdice 7y ago
  Care to elaborate?
  - Dylan16807 7y ago
    You can't make a copy-on-write copy of a file. You can't deduplicate existing files, or existing snapshots. You can't defragment. You can't remove devices from a pool. That last one is likely to get some kind of hacky workaround. But nobody wants to do the invasive changes necessary for actual BPR to enable that entire list.
    - ColanR 7y ago
      Wow. As a casual user - someone who at one point was trying to choose between RAID, LVM and ZFS for an old NAS - some of those limitations of ZFS seem pretty basic. I would have taken it for granted that I could remove a device from a pool or defragment.

ac29 7y ago

Many of the advanced features aren't implemented yet though, like compression, encryption, snapshots, RAID5/6....

jeltz 7y ago
Compression and encryption have been implemented, but not snapshots and RAID5/6.
mschuster91 7y ago
why would you want to embed raid5/6 in the filesystem layer? Linux has battle-tested mdraid for this, I'm not going to trust a new filesystem's own implementation over it. Same for encryption, there are already existing crypto layers both on the block and filesystem (as an overlay) level.
- wheybags 7y ago
  Because the FS can be deeply integrated with the RAID implementation. With a normal RAID, if the data at some address is different between the two disks, there's no way for the fs to tell which is correct, because the RAID code essentially just picks one, it can't even see the other. With ZFS for example, there is a checksum stored with the data, so when you read, zfs will check the data on both and pick the correct one. It will also overwrite the incorrect version with the correct one, and log the error. It's the same kind of story with encryption, if its built in you can do things like incremental backups of an encrypted drive, without ever decrypting it on the target.
  - vetinari 7y ago
    > With a normal RAID, if the data at some address is different between the two disks, there's no way for the fs to tell which is correct, because the RAID code essentially just picks one, it can't even see the other. That's problem only with RAID1, only when copies=2 (granted, most often used case) and only when the underlying device cannot report which sector has gone bad.
  - notacoward 7y ago