Bug#572376: linux-base: Please use UUID for swap, not LABEL

[Josh Triplett <josh@joshtriplett.org>]

On Thu, Mar 04, 2010 at 01:50:41PM +0000, Ben Hutchings wrote:
> On Wed, 2010-03-03 at 23:26 -0800, Josh Triplett wrote:
> > On Thu, Mar 04, 2010 at 01:01:02AM +0000, Ben Hutchings wrote:
> > > On Wed, 2010-03-03 at 11:41 -0800, Josh Triplett wrote:
> > > > Package: linux-base
> > > > Version: 2.6.33-1~experimental.2
> > > > Severity: normal
> > > > 
> > > > The conversion script decided to use LABEL=myhostname-swap for my swap
> > > > partition.  Swap partitions support UUIDs too; please consider using
> > > > those instead.
> > > 
> > > I think labels are far more user-friendly since they are actually
> > > memorable.  Therefore, for devices that have both a label and a UUID,
> > > the label will be used, and for devices that have neither, a label will
> > > be generated.  You are free to reject the plan and edit files yourself.
> > > Unless you can give a very good reason why UUIDs are preferable, I will
> > > not implement this.
> > 
> > I can give several good reasons.
> > 
> > UUIDs generally can't collide; labels can.  Bad Things could happen if
> > two different partitions end up with the same label.
> 
> That's why I include the hostname in generated labels, and avoid all the
> existing disk labels.

And hostnames, of course, can *never* collide between similar systems.
;)

> > Consider what would happen if you had a Linux install on a USB flash
> > drive.  (I have several specialized Debian systems that run off USB
> > drives.)  What happens if you plug a system with a partition labeled
> > "/" into a system which already has a partition labeled "/"?
> > 
> > UUIDs generally won't appear anywhere where "user-friendly" matters.
> > Users shouldn't fiddle with /etc/fstab or similar unless they have a
> > clue.  Graphical tools will use a label if available, even if the actual
> > mount call doesn't.
> 
> And clueful users can remember UUIDs, can they?

Clueful users can copy/paste from /etc/fstab or the output of mount, or
they can use the device names like they frequently already do.

> > Furthermore, filesystems won't necessarily already have labels, while
> > all filesystems *should* have UUIDs.
> 
> Though this is not yet true for swap partitions.

Hmmmm, annoying that mkswap didn't already set UUIDs by default, but
at least all future swap partitions can have them by default.

> > A few references I found:
> > 
> > http://www.mail-archive.com/debian-user@lists.debian.org/msg478822.html
> > https://bugzilla.redhat.com/show_bug.cgi?id=364441
> > 
> > Does all of this provide sufficient reason, or should I provide more?
> > :)
> 
> There is one argument you missed: consistency with new installations,
> which do use UUIDs.  So I will consider doing this now, but it's quite a
> lot of work.

Greatly appreciated work, though.  Thank you for your efforts.

- Josh Triplett