[OT] LABEL vs UUID [was: Re: Adding a drive]

[Joe(theWordy)Philbrook]

It would appear that on Apr 8, Steve Morris did say:

> I was speaking about the label only being changeable at format time in
> relation to reiserfs, which is what I mainly use. I get this impression from
> the documentation for the reiserfs tools package that if I remember correctly
> states explicitly that it is only changeable at format time.

I don't know much about reiserfs, but according to:

http://manpages.ubuntu.com/manpages/hardy/man8/reiserfstune.8.html

reiserfstune has an option, "-l | --label LABEL", to set the label...

> The issue I had with uuid was with a swap partition. I was trying to create 2
> swap partitions which I had previously done without any issues, and the
> partition manager I was using placed an invalid uuid on the partition and
> refused to format it. I tried to place the 2 partitions in a software raid 0
> array but adadm complained that the uuid was invalid and refused to touch it.
> If I manually placed an entry in fstab for this swap partition and specified
> the uuid that the partition manager displayed the system refused to use it,
> and if I used the /dev/sdx specification the system still refused to use it as
> a swap partition.

Another good reason to use LABEL. And perhaps a manual cli tool to
set up a swap... One simply needs the current /dev/Xdx# of the
swap partition. I usually double check with:

fdisk -l

Then if, for example, fdisk reported the swap partition as /dev/sda12. 
And if, The desired label was "karmicSWAP" then

mkswap -L karmicSWAP /dev/sda12

Of course if there's any chance it could already be mounted, I'd do an:

swapoff /dev/sda12  

just before the mkswap command... ;-)

I don't use raid, so I can't say much about adadm. But since mkswap
formats the partition that invalid UUID should be gone as well. 

Lotsa luck

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