How to load sata_nv before pata_amd on Kubuntu Hardy 8.04

[Reinhold Rumberger]

On Monday 08 November 2010, Ric Moore wrote:
> Being an old grey head, I have yet to figure out WTF UUID's are
> supposed to do for me. I MUCH prefer just using the actual
> devices.

device files :-P
(not just being a smartass either - the device file != device thing 
is pretty much the main reason for UUIDs)

There are a couple of problems with this:
a) add/remove partitions and suddenly your swap entry in fstab points
   to your home partitions (device name change due to re-
   partitioning)
b) some hardware has funny little timing issues where the order in
   which devices become visible to the kernel, e.g. when you have
   both sata and pata hard drives - this may cause them to swap names
   so that every other boot the pata may be sda whereas the rest of
   the time it is sdb
c) see Nigel's case. Different distros/kernel versions may load
   modules in a different order, causing sda of one distro to be the
   sdb of the other. This just causes confusion

Have a google - there are other, more bizarre cases for UUIDs/labels.

> They only thing I can imagine would benefit by such a
> scheme would be a RAID device. Is that correct? Someone want to
> educate me on this? I'd appreciate being clued in. Ric

grub and other bootloaders are affected by these issues, too. This 
means that in some cases, UUIDs/labels are the only way to keep them 
booting properly, especially after a partitioning change.

Another way of putting it:
By using e.g. /dev/sda, you're addressing the first drive the kernel 
happens to see, not any particular device. Add to this the fact that 
partitions aren't always as stable as you'd like them to be and that, 
should you ever modify partitions, you'll probably forget some 
important place that needs to be adjusted...
Having a stable addressing scheme for your more important partitions 
is a nice thing to have.

Now consider the case where some people I know put their Ubuntu on an 
external USB hard drive. Since they probably would like to use other 
USB drives that may or may not become visible before the Ubuntu 
drive, they'd have quite a bit of trouble without UUIDs/labels.


Hope to have given you something to think about...

  --Reinhold