[arch-general] Problems with mounting linux partition with gid

[Jared Casper]

On Thu, Jun 26, 2008 at 8:00 AM, Ralph Alvy <ralph at ralphalvy.com> wrote:
> I have no problems mounting via fstab my vfat partitions with an option
> like 'gid=100'. However, I can't seem to get that to work with a Linux data
> partition. That partition is formatted ext3. I also tried 'grpid=100', to
> no avail. Dmsg gives me an 'Unrecognized mount option' error with these.
>

You can only set the gid of the vfat partition because those files
don't already have a group or user id associated with them (vfat
doesn't have any notion of uid/gid).  The ext3 partition already has a
uid/gid associated with each file, so you can't override that.  The
grpid option for ext2/ext3 partitions affects how newly created files
get their group id (whether it comes from the process that created the
file, or the group of the directory) and is an on/off thing (i.e. you
don't set it to a value).

> How do I create a Linux data partition that's fully accessible to me, as
> user, after boot?
>

If all the files on the partition already have a particular gid, you
can just add yourself to that group.  Alternatively you can change the
gid of all the files (as Dennis just showed).  However, remember that
files often don't have group write permissions, so most likely you'll
only be able to read and execute the files, and not write them
(depending on their group permissions).

Jared