Re: Query about command line commands

[Simon Hobson]

Bret Busby <address@hidden> wrote:

> Plurry UUID - those things should be banned, and devices, eg
> "/dev/sda<x>/", or, as in PC-BSD output below, "ada<y>p<x>" should be
> used, to make it all less obscurantist and more user-friendly - "the
> way it used to be".

They were introduced to fix a very real problem - and one that I've been hit 
with.
If you only have one disk then you're not affected. If you have multiple disks 
but on one controller, then you *probably* are not affected. If you have disks 
on multiple controllers/controller types then you are affected.

It's to do with the indeterminate way that controllers may be located and 
drivers loaded. There's no way to guarantee that what appears to the OS as sda 
*on this boot* will be sda to the bootloader - or even to the same OS on the 
next boot.

Personally I prefer to use filesystem labels - Debian doesn't support that in 
it's packaging of Grub, though it does support using device names (eg sda). It 
will do what using UUID does - but it does need admin intervention to set the 
labels *AND* the admin has to make sure the labels are unique. That includes 
allowing for (say) calling your root filesystem "root" and then connecting an 
external drive which also has a filesystem called "root".

So while they are a bit of a PITA when you have to copy and type them, they are 
there for a good reason.