Label your EXT3 partitions!

If you have removable drives used for backup or portable media, and you're using EXT3 rather than FAT16 (the default format of most USB flash drives), mounting these drives by their Linux device name is ambiguous. For example, I have a hard drive in a Venus DS-3 with a single EXT3 partition on it. The problem is, making the entry in the /etc/fstab file. The /dev/sd[a-z][1-9] designation is not good enough because it changes with the order of the connections during boot-time or plug-in time.

Making labels for each partition to be mounted fixes the problem entirely. To create a label for an ext2/ext3 partition, use the e2label command:

e2label [device] [label]

My exact command was:

e2label /dev/sde1 "Venus1"

Note that I had to find the right drive using 'fdisk' before I knew it was 'sde1'.

The change takes place right away, and then you can put a line in your /etc/fstab like:

LABEL="Venus1"          /media/venus1           ext3    noauto          0 0

And it will run through the drives to find the right label. We've associated the mount location with the partition on the physical device. This is especially important if you're mounting the drives on a server and are not using any automatic mounting facility.

Some recommend to also label the static partitions if you're using only EXT3. If you're using LVM, the groups and volumes are already labeled.

Alternatively, you may use a UUID, obtained from

udevinfo -q env -n /dev/sdd1

Where sdd1 is your USB device, which you can find from

fdisk -l

There is a lot more info you can get with udevinfo but for now, just grab the ID_FS_UUID and you can use it in your /etc/fstab as follows:

UUID=492bc203-de77-40b6-be4b-49e84fee430e /data ext3 auto,defaults 0 0

See http://www.patrickmin.com/linux/tip.php?name=usbkey_mount and
http://floatingsun.net/articles/howtos/howto-usb-automount.html for more.