quick linux question: drive allocation

cyrilthefish · 6 Oct 2007

currently backing up my server pc to swap a few drives around (my mum is complaining sims2 takes too long to load, so i'm going to swap her old 40GB HD in her PC for a raid0 array )

anyway, current server pc config:

xubuntu linux
40GB drive, hda = / mount
2x80GB LVM, hdb+hdc = /home mount

what i want to do is take out the two 80GB drives and replace with a single 160GB drive i have spare
the 160GB drive is currently connected via a USB-IDE adapter (sda) and i'm rsync'ing the contents of /home to it as we speak.

now when i take the two 80GB drives out and swap in the 160GB as secondary IDE master (the 40Gb is primary IDE master), will it:

-set itself to hdb
-set itself to hdc

i can't remember if linux allocates drive name by location or order...

i want to se the FSTAB file to be correct the first time i boot with the new setup to hopefully stop it breaking itself when it sees no /home mount available

IanW · 8 Oct 2007

Currently, the various flavours of Ubuntu prefer to allocate drives by UUID (Universally Unique IDentifier), although the older hda1/hdb1 method still works.
As the name suggests, this is a unique ID number for each drive, so it will mount in the correct place no matter which port it's connected to.

To generate one for your new drive:-
Code:
$ sudo vol_id -u /media/sda1
(This assumes the drive is currently mounted as /media/sda1 of course)

and paste the resulting UUID number into the /etc/fstab entry for your home directory ( / ) when you are about to shut the system down to install the drive.

As always, TAKE A BACKUP FIRST! Just in case what I wrote above is totally wrong!