Re: Read before you deploy btrfs + zstd

[Dmitrii Tcvetkov <demfloro@demfloro.ru>]

On Wed, 15 Nov 2017 20:23:44 +0000 (UTC)
Duncan <1i5t5.duncan@cox.net> wrote:
> Tho from my understanding and last I read, btrfs restore (I believe
> it was) hadn't been updated to handle zstd yet, tho btrfs check and
> btrfs filesystem defrag had been, and of course btrfs balance if the
> kernel handles it since all balance does is call the kernel to do it.
> 
> So just confirming, does btrfs restore handle zstd from -progs 4.13?  
> 
> Because once a filesystem goes unmountable, restore is what I've had
> best luck with, so if it doesn't understand zstd, no zstd for me.  
> (Regardless, being the slightly cautious type I'll very likely wait a 
> couple kernel cycles before switching from lzo to zstd here, just to
> see if any weird reports about it from the first-out testers hit the
> list in the mean time.)
> 
> Meanwhile, it shouldn't need said but just in case, if you're using
> it, be sure you have backups /not/ using zstd, for at least a couple
> kernel cycles. =:^)
> 

Btrfs-progs 4.13 can be optionally built with libzstd, then btrfs
restore can restore from zstd compressed file systems (I tested that
right now with temporary fs using compress-force=zstd mount option).

Btrfs-progs 4.14 will require libzstd by default during build.