[Linux-users] Mini rant: sda vs hda

[Collins Richey]

On 8/31/07, Sean Keating <sean at csupport.com> wrote:
> The problem will be apparent when you try to plug in an external, USB
> device (like a USB hard drive.)  It will also be an "sb" device and will
> not unmount easily. Some devices work fine, others don't.  I use Feisty,
> and I like it a lot, but it took me a while to figure this one out.
>
> Also, let me warn you.  Notice that in fstab your drive is mounted by
> its UUID not its device. (This probably has something to do with why its
> sda instead of hda.)  I use gparted to periodically duplicate my drive
> to an external USB drive as a backup.  If I forget to assign it a new
> UUID and plug it in, it hides my actual drive.
>

The principal reason for using UUID as the boot identifier is to
eliminate the vagaries of device numbering inherent in the bios when
new devices are added to the system, exactly the type of problem you
are alluding to. The UUID is always (supposed to be?) unique whereas
/dev/[h|s]da can change.
-- 
Collins Richey
     If you fill your heart with regrets of yesterday and the worries
     of tomorrow, you have no today to be thankful for.