btrfs support status

[tgm]

btrfs has been in preview for a while. What is the status of bringing it to full production? Interest centers with using it to reduce memory needs vs zfs.

 

[rreive]

What is the ram reduction difference using btrfs vs zfs in your estimation? Also which RAID setup are you looking to implement? ty in advance,

just fyi- we are btrfs centric where I work and are in the process of evaluating ProxMox VE and related Backup Service with btrfs across different raid configs to take advantage of thin provisioning of shared capacity, so any info you can share would be useful.

 

[LnxBil]

What is the ram reduction difference using btrfs vs zfs in your estimation?

None, as with any filesystem on the planet. The operating system will cache as much as possible. The difference is how this memory is allocated and that ZFS uses - depending on its root in Solaris (solaris portability layer) - different methods so that the memory cannot be released as fast as it would be in other filesystems with use the kernels default buffer cache logic.

 

[esi_y]

None, as with any filesystem on the planet. The operating system will cache as much as possible. The difference is how this memory is allocated and that ZFS uses - depending on its root in Solaris (solaris portability layer) - different methods so that the memory cannot be released as fast as it would be in other filesystems with use the kernels default buffer cache logic.

While I do not see in-depth into ZFS & BTRFS, I do not think it is about "reduction" in terms of "more left over" - ZFS simply needs RAM. Even e.g. adding L2ARC increases the RAM requirement. This is definitely not true equally for each arbitrary filesystem. I had low RAM configurations where ZFS would be outright unstable, but BTRFS be just fine.

 

[LnxBil]

I do not think it is about "reduction" in terms of "more left over" - ZFS simply needs RAM.

The OOM situation is, sadly, yet of course does ZFS need RAM for manage itself (see next point).

I had low RAM configurations where ZFS would be outright unstable, but BTRFS be just fine.

That is true. I'm talking solely on the upper end of the problem, not on the lower end.

Even e.g. adding L2ARC increases the RAM requirement.

Yes, that's one of the main points against L2ARC if you don't have enough ARC, it will in theory and in practice make your pool slower and if it helps will only be shown in your metrics. I didn't see any improvement in mine, so I dropped it and put in more RAM and more special devices.