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I have the following line in /etc/fstab:

none  /home/hydra/tmp  tmpfs  user,noauto,size=1000M,uid=1001,gid=1001  0  0

I can do mount ~/tmp as user hydra and it gets mounted ok. The only problem is that even thought it gets added to /proc/mounts, it does not get added to /etc/mtab. When I try a umount ~/tmp (again as hydra) it complains:

umount: /home/hydra/tmp is not mounted (according to mtab)

And when I try -f or -n, it complains that I am not root.

Some more info on the system that manifests this problem:

On sudo umount /home/hydra/tmp, the fs gets unmounted (I think I needed to used -f too)

  • Debian version is testing
  • mount --version -> mount from util-linux 2.19.1 (with libblkid and selinux support)
  • ls -l /etc/mtab -> -rw-r--r-- 1 root root 921 Nov 14 09:08 /etc/mtab
  • cat /proc/mounts | grep rootfs -> rootfs / rootfs rw 0 0
  • /home, /home/hydra nor /home/hydra/tmp are symbolic links
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What happens when you run this as root? –  PriceChild Nov 11 '11 at 16:11
i think you have columns switched around in /etc/fstab. and what's the none for in the first column? tmpfs /home/hydra/tmp user,noauto,size=1000M,uid=1001,gid=1001 0 0 that's how i normally see it –  matt Nov 11 '11 at 16:11
Oh and by the way, having an entry in /etc/fstab makes no difference to the mount command afaik? (i.e. it isn't required) If you wanted to mount a new addition to /etc/fstab, use mount -a –  PriceChild Nov 11 '11 at 16:13
@matt No, vrinek's syntax is correct. The first column is the device name, it's ignored for non-device-backed filesystems such as tmpfs. vrinek: what version of Debian are you running? What version of the mount package? What does ls -l /etc/mtab show? Is / mounted read-only? Is /home or /home/hydra or /home/hydra/tmp a symbolic link (with that tmpfs unmounted, what does readlink -f /home/hydra/tmp show)? –  Gilles Nov 11 '11 at 18:48
@PriceChild An entry in /etc/fstab is required if you want to call mount as a non-root user. –  Gilles Nov 11 '11 at 18:50

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