I have looked on google, searching for a way to do this, I know it should be possible, but I didn't find any information on how to do it.

I have a partition (dev/hda2), that I want to make available to the "guest" user, but as read-only.

The relevant line from my /etc/fstab is:

/dev/hda2 /mnt/hda2 vfat auto,rw

Again, only the "guest" user should be able to access the partition, and only in read-only mode. If it is needed, the UID of the guest user is 1001.

Thanks in advance!

fstab is probably the wrong place to try to set such permissions. fstab tells the systems which partitions, devices, etc., can be mounted; not who can access them. Try setting up a Group to identify who is allowed access to the partition, and put the names of the allowed user's in that group. Then use chown to set the group name in the properties.

I believe what you would need to do is set the permissions for the file that serves as the mount point for that partition.

For instance, I have a partition, /dev/hda12, that has a mount point (a directory) named /data-1. I would then set the ownership and read/write permissions of that file so that when it is mounted it would be accessable (or not) as you wish.

If you set the partition to be mounted read only in fstab, this will be a global setting (I believe) and not what you are looking to do. For instance, if you enter in fstab

noauto,guest,ro

for the partition, this will make guest the only person, other that root, that can mount the partion, but once mounted, all will have ro access to the partition.

HTH

[edit]

I'm not sure what you mean, Franklin.

The partition itself is vfat, chmod won't work on the files themselves. This is what stumps me.

chmoding the /dev/hda2 does not make any difference. Neither does chmoding the /mnt/hda2 (mount point?). Filesystem was umounted before chmod, and remounted afterwards.