Ubuntu Wiki

1. Knowing UUID and other IDs of block devices

note: this is not only for disks physical partitions, bul also for multi-disk devices (RAID) and logical volume devices (LVM)

1.1. blkid

• this will list UUID for all known block devices

  <user>@<host>:~$ blkid
  /dev/sda1: LABEL="sda1-boot-2GB" UUID="a596c61a-16b7-4967-890a-38022722b04d" SEC_TYPE="ext2" TYPE="ext3"
  /dev/sda2: ...

1.2. vol_id

this command is part of udev package and must be run with administratives privileges (as root or with sudo)

• short ID list for one device

  <user>@<host>:~# vol_id /dev/sda1
  ID_FS_USAGE=filesystem
  ID_FS_TYPE=ext3
  ID_FS_VERSION=1.0
  ID_FS_UUID=a596c61a-16b7-4967-890a-38022722b04d
  ID_FS_UUID_ENC=a596c61a-16b7-4967-890a-38022722b04d
  ID_FS_LABEL=sda1-boot-2GB
  ID_FS_LABEL_ENC=sda1-boot-2GB
  ID_FS_LABEL_SAFE=sda1-boot-2GB

• this is just the UUID for one device

  <user>@<host>:~# vol_id -u /dev/sda1
  a596c61a-16b7-4967-890a-38022722b04d

1.3. udevadm

this command is part of udev package and must be run with administratives privileges (as root or with sudo)

this command seems to replace the former udevinfo command

• the following command (see the short form below) does list the env part of the udev db content, for one device. Valid queries are: name, symlink, path, env, all.

  <user>@<host>:~# udevadm info --query=env --name=/dev/sda1
  ID_VENDOR=ATA
  ID_MODEL=Hitachi_HDT72503
  ID_REVISION=V54O
  ID_SERIAL=1ATA_Hitachi_HDT725032VLA360_xxx
  ID_SERIAL_SHORT=ATA_Hitachi_HDT725032VLA360_xxx
  ID_TYPE=disk
  ID_BUS=scsi
  ID_ATA_COMPAT=Hitachi_HDT725032VLA360_xxx
  ID_PATH=pci-0000:00:05.0-scsi-0:0:0:0
  ID_FS_USAGE=filesystem
  ID_FS_TYPE=ext3
  ID_FS_VERSION=1.0
  ID_FS_UUID=a596c61a-16b7-4967-890a-38022722b04d
  ID_FS_UUID_ENC=a596c61a-16b7-4967-890a-38022722b04d
  ID_FS_LABEL=sda1-boot-2GB
  ID_FS_LABEL_ENC=sda1-boot-2GB
  ID_FS_LABEL_SAFE=sda1-boot-2GB

• this short form is not documented in udevadm man and has been borrowed from an udevinfo example:

  <user>@<host>:~# udevadm info -q env -n /dev/sda1