On Fri, 2021-01-08 at 00:03 -0700, Chris Murphy wrote:
On Thu, Jan 7, 2021 at 5:52 AM Patrick O'Callaghan
<pocallaghan(a)gmail.com> wrote:
>
> I did the following:
>
> # btrfs filesystem defragment -czstd -r -v /home
>
> and changed the fstab entry:
>
> # grep /home /etc/fstab
> UUID=8e1f7af4-c0bf-434e-b1c4-a9af2c810d56 /home btrfs
subvol=home,discard=async,compress-force=zstd 0 0
>
> (this is an SSD, hence the discard-async)
>
> I then rebooted, but find:
>
> # btrfs prop get -t i /home compression
> #
> (i.e. no output)
The 'btrfs property' method of setting compression per file,
directory, or subvolume, sets an xattr. The mount option method does
not.
Also, the mount option is file system wide, it's not per subvolume. It
just seems like it could be this way due to fstab and the subvol mount
option (which is really just a bind mount behind the scenes).
Does this mean that my VM image subvolume is being included in the
compression? If that's the case I'll cease and desist.
poc