If you’re creating a zpool on Ubuntu you have several options when it comes to referring to the drives; the most common is /dev/sda, /dev/sdb and so on. This can cause problems with zpools as the letter designated to a drive can change if you move the drives around, add or remove a drive – causing your zpool to come up as faulty. One way to avoid this is to use a more specific name for the disk, one of which is the ID. You can find this on Ubuntu through the following command:
sudo ls -l /dev/disk/by-id/
This gives an output similar to the following:
lrwxrwxrwx 1 root root 9 Oct 19 08:48 ata-ST2000DM001-9YN164_W1F01W57 -> ../../sdd
lrwxrwxrwx 1 root root 9 Oct 19 08:48 ata-ST2000DM001-9YN164_W2400946 -> ../../sdc
lrwxrwxrwx 1 root root 9 Oct 19 08:48 ata-ST2000DM001-9YN164_W24009TB -> ../../sde
lrwxrwxrwx 1 root root 9 Oct 19 08:48 ata-ST2000DM001-9YN164_W2402PBQ -> ../../sdb
lrwxrwxrwx 1 root root 9 Oct 19 08:48 ata-ST2000DM001-9YN164_Z24064V7 -> ../../sda
You can see that the command helpfully points which ID is associated with which /dev/sd?.