5 ms·

A quick review of btrfs

55 points by rcfox 16y ago

pixelbeat 16y ago
The standard cp since coreutils 7.6 supports the --reflink option. This e.g. will copy a file with CoW if possible, but fallback to a standard copy if not: cp --reflink=auto src dst I did a quick summary of how reflinks relate to symlinks and hardlinks at http://www.pixelbeat.org/docs/unix_links.html http://www.pixelbeat.org/docs/unix_links.html
apgwoz 16y ago
> all I know is it's not in the 2.3.36 Linux kernel, but btrfs is, so btrfs wins. I've been out of the Linux kernel loop for ages now, but isn't 2.3.36 over 10 years old? Did they change the naming convention such that development kernels are 2.3 again? If so, why? Or, am I completely missing something?
- pmjordan 16y ago
  Must be a typo for 2.6.36.
  - apgwoz 16y ago
    I assumed that too, but questioned it anyway.
    - JshWright 16y ago
      You assumed that... yet in your list of possible reasons, a simple typo wasn't listed?
      - apgwoz 16y ago
        Listing that as a reason would result in multiple people agreeing that it was a typo and nothing more. If it wasn't a typo, it'd have been overlooked.
kia 16y ago
The funny thing is that BTRFS is developed by Oracle. ZFS was developed by Sun. Now when Oracle bought Sun they have two more or less competing filesystems. What are they going to do about this? Are they going to make ZFS GPL or cancel the development of one of these?
- TheCondor 16y ago
  BTRFS was started by Oracle. There are contributors from Redhat and other places now, it's bigger. Oracle could fire Chris Mason and BTRFS should continue.
  - masklinn 16y ago
    > BTRFS was started by Oracle. There are contributors from Redhat and other places now, it's bigger. Oracle could fire Chris Mason and BTRFS should continue. On the other hand, ZFS works, is pretty stable, and is already available on BSDs as well as Solaris. Furthermore, while the OSX port effort was stopped (apparently due to legal/licensing concerns) it could be restarted depending on Oracle's attitude. And as kia points out, ZFS/btrfs if a redundancy and Oracle "owns" both projects. Oracle tends to eliminate redundancies in product space, so it's unlikely both projects will continue in parallel. I don't think btrfs having been started by oracle will have much impact in the decision.
    - rbranson 16y ago
      I'd argue that btrfs is not a product, but part of their support for the Linux platform. Oracle has a big Linux install base, and the primary commercial competition for these types of installs this is Microsoft SQL Server. The more powerful and useable Linux is, the less attractive a Windows-based option looks.
      - masklinn 16y ago
        > I'd argue that btrfs is not a product, but part of their support for the Linux platform. Which makes the whole thing even more likely: they can provide the same amount of support by porting ZFS to Linux.

55 points by rcfox 16y ago

The standard cp since coreutils 7.6 supports the --reflink option. This e.g. will copy a file with CoW if possible, but fallback to a standard copy if not: cp --reflink=auto src dst I did a quick summary of how reflinks relate to symlinks and hardlinks at http://www.pixelbeat.org/docs/unix_links.html http://www.pixelbeat.org/docs/unix_links.html

apgwoz 16y ago

> all I know is it's not in the 2.3.36 Linux kernel, but btrfs is, so btrfs wins. I've been out of the Linux kernel loop for ages now, but isn't 2.3.36 over 10 years old? Did they change the naming convention such that development kernels are 2.3 again? If so, why? Or, am I completely missing something?

pmjordan 16y ago
Must be a typo for 2.6.36.
- apgwoz 16y ago
  I assumed that too, but questioned it anyway.
  - JshWright 16y ago
    You assumed that... yet in your list of possible reasons, a simple typo wasn't listed?
    - apgwoz 16y ago
      Listing that as a reason would result in multiple people agreeing that it was a typo and nothing more. If it wasn't a typo, it'd have been overlooked.

kia 16y ago

The funny thing is that BTRFS is developed by Oracle. ZFS was developed by Sun. Now when Oracle bought Sun they have two more or less competing filesystems. What are they going to do about this? Are they going to make ZFS GPL or cancel the development of one of these?

TheCondor 16y ago
BTRFS was started by Oracle. There are contributors from Redhat and other places now, it's bigger. Oracle could fire Chris Mason and BTRFS should continue.
- masklinn 16y ago
  > BTRFS was started by Oracle. There are contributors from Redhat and other places now, it's bigger. Oracle could fire Chris Mason and BTRFS should continue. On the other hand, ZFS works, is pretty stable, and is already available on BSDs as well as Solaris. Furthermore, while the OSX port effort was stopped (apparently due to legal/licensing concerns) it could be restarted depending on Oracle's attitude. And as kia points out, ZFS/btrfs if a redundancy and Oracle "owns" both projects. Oracle tends to eliminate redundancies in product space, so it's unlikely both projects will continue in parallel. I don't think btrfs having been started by oracle will have much impact in the decision.
  - rbranson 16y ago
    I'd argue that btrfs is not a product, but part of their support for the Linux platform. Oracle has a big Linux install base, and the primary commercial competition for these types of installs this is Microsoft SQL Server. The more powerful and useable Linux is, the less attractive a Windows-based option looks.
    - masklinn 16y ago
      > I'd argue that btrfs is not a product, but part of their support for the Linux platform. Which makes the whole thing even more likely: they can provide the same amount of support by porting ZFS to Linux.