Automounter tutorial

autofs, also called automounter or automount, allows you to connect storage media like a USB disk and have it mounted automatically. For example, if you have two USB disks, and you want to have one mounted as usb-120gb and the other as usb-80gb as soon as you plug them in, this is possible with autofs.

QuickStart

This example assumes you want to plug in a USB disk and have it mounted on /misc/usb.

• install autofs

• Find out your USB disk's UUID:

hwinfo --block
[...]
  Device Files: /dev/sdc1, /dev/disk/by-id/usb-Myson_Century,_Inc._USB_Mass_Stor
age_Device_100-part1, /dev/disk/by-path/pci-0000:00:1d.7-usb-0:3:1.0-scsi-0:0:0:
0-part1, /dev/disk/by-uuid/84ff6790-9b69-4401-9ba2-43d044af1d30, /dev/disk/by-la
bel/DATALUX

Configure autofs

Have a file /etc/auto.master like this:

/misc   /etc/auto.misc --timeout=60 --ghost

This will create all mount points beneath /misc. The mount points will appear even if they are not active ("ghosts").

Create a file /etc/auto.misc like this:

usb       -fstype=auto            UUID="84ff6790-9b69-4401-9ba2-43d044af1d30"

Start autofs

systemctl start autofs || /etc/init.d/autofs start

Now you can find your USB disk automatically mounted to /misc/usb.

Make it persistent

Now, as soon as you plug in your USB disk you will find its content under /misc/usb. If you want this setting to persist after reboots, run the command:

chkconfig autofs on

TroubleShooting

• You can find log entries from automounter NOT in dmesg but in /var/log/messages.
• If your device is already mounted, automount may not mount it again. This means you will also have to stop other automounters like gnome-volume-manager.