how to make a cache directory nodatacow while also excluded from snapshots?

how to make a cache directory nodatacow while also excluded from snapshots?

[Dave]

I want to exclude my ~/.cache directory from snapshots. The obvious
way to do this is to mount a btrfs subvolume at that location.

However, I also want the ~/.cache directory to be nodatacow. Since the
parent volume is COW, I believe it isn't possible to mount the
subvolume with different mount options.

What's the solution for achieving both of these goals?

I tried this without success:

    chattr +C ~/.cache

Since ~/.cache is a btrfs subvolume, apparently that doesn't work.

    lsattr ~/.cache

returns nothing.

Re: how to make a cache directory nodatacow while also excluded from snapshots?

[Andrei Borzenkov]

16.01.2018 00:56, Dave пишет:
> I want to exclude my ~/.cache directory from snapshots. The obvious
> way to do this is to mount a btrfs subvolume at that location.
> 
> However, I also want the ~/.cache directory to be nodatacow. Since the
> parent volume is COW, I believe it isn't possible to mount the
> subvolume with different mount options.
> 
> What's the solution for achieving both of these goals?
> 
> I tried this without success:
> 
>     chattr +C ~/.cache
> 
> Since ~/.cache is a btrfs subvolume, apparently that doesn't work.
> 
>     lsattr ~/.cache
> 
> returns nothing.

Try creating file under ~/.cache and check its attributes.