[SOLVED] Unrecognized mount option "uid=1002" or missing value

mfoley · 08-11-2017, 04:58 PM

I'm trying to mount an external USB drive:

Code:

# mount -t ext4 /dev/sdc1 /mnt/OHPRSbackup -o uid=ohprs,gid=ohprs,flush
mount: wrong fs type, bad option, bad superblock on /dev/sdc1,
       missing codepage or helper program, or other error

       In some cases useful info is found in syslog - try
       dmesg | tail or so.

syslog has:

Code:

Aug 11 17:52:39 bu6500 kernel: [3563338.712562] EXT4-fs (sdc1): Unrecognized mount option "uid=1002" or missing value

But, that seems to be a legit option in man mount. Also, this has worked in the past. The only different is that now the file system is ext4 and before it was ntfs.

The uid is correct for user ohprs.

What am I doing wrong?

55020 · 08-11-2017, 05:07 PM

Quote:

Originally Posted by mfoley

What am I doing wrong?

Reading the manpage.

For all filesystem types, you can use the options described under "FILESYSTEM-INDEPENDENT MOUNT OPTIONS". These include 'group' and 'user', but not 'uid' and 'gid'.

For ext4, you can also use the options described under "Mount options for ext4". No 'uid' and 'gid' there.

For ntfs, 'uid' and 'gid' do exist, but have semantics that differ from 'group' and 'user'.

Edit: You're not going to have much joy with 'flush', either, which applies only to fat filesystems.

mfoley · 08-12-2017, 11:13 AM

Ah! You are right! The "ntfs options" bit on the man page had scrolled off my screen, so I didn't realize uid was applied to it and not ext4. I'm using:

Code:

mount -t -ext4 /dev/sdc1 /mnt/OHPRSbackup -o user=ohprs,rw

and that works fine ... for one drive. Still having issues.

I have an identical drive for which I'm trying to do the same thing on the same computer, but it's not working:

Code:

# mount -t ext4 /dev/sdd1 /mnt/mirror/ -o user=ohprs,rw
# exit
ohprs $ touch /mnt/mirror/joe
touch: cannot touch '/mnt/mirror/joe': Permission denied

$ df
/dev/sdc1      4845160336  94744712 4506210716   3% /mnt/OHPRSbackup
/dev/sdd1      4845160336     64440 4600890988   1% /mnt/mirror

$ ls -l /mnt
drwxrwxrwx 7 root root 4096 2017-08-12 02:23 OHPRSbackup/
drwxr-xr-x 3 root root 4096 2017-08-11 17:40 mirror/

$ sudo umount /mnt/mirror
$ ls -l /mnt
drwxrwxrwx 7 root root 4096 2017-08-12 02:23 OHPRSbackup/
drwxrwxrwx 2 root root 4096 2017-02-20 23:16 mirror/

The difference is that before mounting /mnt/mirror is a+rwx, but after mounting it reverts to go-w. Yet the one that works, /mnt/OHPRSbackup stayed with a+rwx. Not sure why, maybe I set the permissions on /mnt/OHPRSbackup after mounting? I don't remember (it's running a backup at the moment so I can't umount it).

So, what do I need to do to make a mount writable by a non-root user?

mfoley · 08-13-2017, 06:15 PM

Do I need a new topic with a different title? I need an fstab entry that will permit root to mount an external USB drive that non-root users can access. Surely this has been addressed long ago, although I've not found a solution searching the Web.

Anybody?

55020 · 08-13-2017, 06:18 PM

You answered it yourself already -- chmod the mounted directory.

mfoley · 08-14-2017, 11:45 AM

You're right. Actually, I think my problem is not permissions. It has to do with rsync. I'll post a different thread.