The Universally Unique Identifier can be used to identify a device independent form its mount point or device name. This is more and more important as many devices today support hot-plugging or are external anyway. Therefore it makes sometimes sense to access a device (for example in fstab) not by device name but by the UUID.
There are several ways to get the UUID. The first one uses the /dev/ directory. While you are on is you might want to check other by-* directories, I never knew of them.
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$ ls -l /dev/disk/by-uuid |
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lrwxrwxrwx 1 root root 10 11. Okt 18:02 53cdad3b-4b01-4a6c-a099-be1cdf1acf6d -> ../../sda2 |
Another way to get the uuid by usage of the tool blkid:
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$ blkid /dev/sda1 |
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/dev/sda1: LABEL="/" UUID="ee7cf0a0-1922-401b-a1ae-6ec9261484c0" SEC_TYPE="ext2" TYPE="ext3" |
There you also get the label and other information. Quite usefule.
Btw., if you wonder how “unique” this unique is, here a quote from Wikipedia:
1 trillion UUIDs would have to be created every nanosecond for 10 billion years to exhaust the number of UUIDs.
Pretty unique.
Thanks to Linux By Examples for the initial howto.
Original link：
http://liquidat.wordpress.com/2007/10/15/short-tip-get-uuid-of-hard-disks/
