Fedora Developers Evaluating Compression Options For Btrfs-By-Default Proposal

[RomuloP]

I wish I could remember where I read this, but with BTRFS+Zstd you want to exclusively use "compress-force" because "compress" will use the kernel's built-in heuristic to skip files where as "compress-force" will use Zstd's faster heuristic.

In fact kernel heuristic was fast but poor. I'm not sure this is a problem since kernel 4.15. Kernel heuristic nowadays is quite sophisticated and probably as fast according to btrfs wiki, only bench-marking to be sure it is worth it.

[skeevy420]

BTRFS does the same per file, zstd can skip in-compressible data automatically. And the heuristic is pretty fast, more than 1GB/s per thread. To the point you have `compress` and `compress-force`

I wish I could remember where I read this, but with BTRFS+Zstd you want to exclusively use "compress-force" because "compress" will use the kernel's built-in heuristic to skip files where as "compress-force" will use Zstd's faster heuristic.

[antonyshen]

I use BTRFS w/ zstd:3 compression on Ubuntu, including a rpi4 installation. I love BTRFS, it's much much more usable that before, offers lots of useful features.

[RomuloP]

FreeBSD's been doing this for 10 years or better now.. They just pretty much turn on lz4 for almost everything non base due to lz4 skipping files it can't compress quickly.

BTRFS does the same per file, zstd can skip in-compressible data automatically. And the heuristic is pretty fast, more than 1GB/s per thread. To the point you have `compress` and `compress-force`

[RomuloP]

The only thing I miss implementation is encryption and the only thing I miss a fix is quotas... Quotas have a huge performance impact but is a relevant feature.

[RahulSundaram]

Is there any reason why xfs isn't the default?

I would be perfectly happy with btrfs, it just seems to me that xfs provides the path of least resistance away from ext4.

XFS is the default for Fedora server. For workstation, shrinking was considered important and the feature set for Btrfs is quite different

[ezst036]

Is there any reason why xfs isn't the default?

I would be perfectly happy with btrfs, it just seems to me that xfs provides the path of least resistance away from ext4.

[ThoreauHD]

They really need to not F that up. Torvalds uses that OS, and CoC or not, he'll rip them if they don't test reality.

[k1e0x]

FreeBSD's been doing this for 10 years or better now.. They just pretty much turn on lz4 for almost everything non base due to lz4 skipping files it can't compress quickly.

Dataset compression settings:
zpool compression off
zpool/ROOT compression off
zpool/ROOT/initial compression lz4
zpool/root compression lz4
zpool/tmp compression lz4
zpool/usr compression off
zpool/usr/home compression lz4
zpool/usr/jails compression lz4
zpool/usr/obj compression lz4
zpool/usr/ports compression lz4
zpool/usr/src compression lz4
zpool/var compression off
zpool/var/audit compression lz4
zpool/var/log compression lz4
zpool/var/mail compression lz4
zpool/var/tmp compression lz4

That is a pretty simple laout, binaries are left uncompressed (inherit from /usr) If you're looking for a model.. that is a good start. Ubuntu I know has taken a more varied layout but it's similar.

[cjcox]

Thin provisioning, over provisioning and/or compression == future "surprise" failure.