I appreciate that this has been asked time and time again, but I would like some clarification on fstab permissions. Unfortunately, I am unable to add comments to existing threads, as I don't have enough reputation (I must be missing the point of this restriction!).
Anyway, I have formatted a partition on a new disk as FAT, and have found that I cannot write to it. I understand that I need to change my fstab entry to include 'options', which in turn require UID and GID. All the instructions I have read direct me to use 'a' users GID, and they all appear to instruct the 'primary group' for a user (as shown in /etc/passwd or 'id -g').
I must admit, I don't undertand the concept of a primary group, other than a user must be assigned to at least one group. My undertanding of using GID and UID within fstab, is that it assigns the user and group ownership of the mount.
I would like all members of 'another' group, such as 'adm' to have write access to the mount (being shared by samba). Instead of using the primary group for a discrete user/UID, can I use a different (any other) groups GID? This seems a logical thing to do, so perhaps I have completely misunderstood these options entirely.