UUIDs in fstab

[Andrew Farris]

Patrick O'Callaghan wrote:
> On Tue, 2008-04-29 at 22:40 -0700, Andrew Farris wrote:
>> Chuck Anderson wrote:
>>> On Wed, Apr 30, 2008 at 12:35:41AM -0400, Christopher L Tubbs II wrote:
>>>> Granted, I understand that a UUID is just as good as a LABEL, as far as 
>>>> functionality goes, but LABELs are so much easier to read, compare, and 
>>>> type. Why would the F9 installer choose to create UUIDs instead of readable 
>>>> LABELs? I have no idea.
>>> UUIDs are unique.  LABELs may not be.
>> This is precisely the reason, because the realization has hit people that a 
>> system may have many linux distros installed on it, so labels made by other 
>> distros for '/' are not unique; at the same time the device names are no longer 
>> guaranteed to be in any particular ordering when some devices come and go 
>> (hotswapped drives especially).  UUIDs are the identifier that won't get mixed 
>> up or changed.
> 
> It seems to me that there are two issues here:
> 
> 1) How do I identify my disks/partitions so I know what's going on?
> 2) How do I tell the system what to mount where in a consistent manner.
> 
> Labels solve 1 but may fail at 2. UUIDS solve 2 but are awkward for 1.
> 
> So, off the top of my head, why not use both? It's trivial for the
> system to notice when two partitions have the same label, so at install
> time (or mount time, or whatever) it could simply offer to change one of
> them, e.g. if I have LABEL=foo on two partitions, relabel them foo-1 and
> foo-2. Keep the UUIDs but make the labels work for the humans among us.

The problem does not only arise at install time.  In fact, thats the simple 
case.  If you move a disk from system to system you could get it booting the 
wrong system because labels conflict, when during install it was fine.  So you 
need to make sure when two systems are installed their labels will be 
sufficiently unique... foo-UUID might work fine for that but anything short of 
it fails.

-- 
Andrew Farris <lordmorgul at gmail.com> www.lordmorgul.net
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