Can you mount with a specific group?

[danielkrajnik]

I'm trying to mount mergerfs with a specific group, but I can't seem to find it documented anywhere. Is this possible at all?

/usr/bin/mergerfs \
  -f \
  -o cache.files=partial \
  -o dropcacheonclose=true \
  /mnt/mount1:/mnt/mount2=NC \
  /mnt/merger

I've tried adding -o gid=1001 or -o group=new-group, but nothing works (it always takes the group of the current user).

[trapexit]

What do you mean by "mount with a specific group"?

[danielkrajnik]

Thank you for the quick reply. I'm trying to make the /mnt/merger folder's group permissions to be different than the user, e.g. ls -l /mnt :

drwxrwx--- - user new-group 26 Jun 17:56  merger/

Even if you change permissions for that folder before mounting mergerfs it still overrides them.

[trapexit]

Can you explain the usecase? Why not just change the ownership of the paths?

As with most libfuse apps mergerfs has -o gid=x and uid=y to override values. If that doesn't work for your purposes I'm not sure what exactly you're looking for.

[danielkrajnik]

As with most libfuse apps mergerfs has -o gid=x and uid=y to override values

Thanks, that helped. I forgot that you need to also specify uid (I was only passing gid). This works:

  -o uid=1000 \
  -o gid=1001 \
  -o umask=007 \

Sadly it didn't solve my problem, but that's unrelated to mergerfs. I'm trying to pass the filesystem to a virtual machine via virtiofs daemon, which runs under a different user (libvirt-qemu). Normally sharing filesystem via samba doesn't require different permissions, because it runs under the user. This however keeps giving this cryptic error: the virtiofs export directory '/mnt/merger' does not exist . I thought that was caused by permissions, but it's still the same even after changing them. Oh well...