Re: Request for enhancement [Re: Question about /etc/fstab in Squeeze]
On 20101220_173710, Stephen Powell wrote:
> On Sun, 19 Dec 2010 11:44:35 -0500 (EST), Rick Thomas wrote:
> > On Dec 19, 2010, at 8:09 AM, Stephen Powell wrote:
> >> Caution: reformatting a swap partition with mkswap will change the
> >> uuid unless the existing one is explicitly re-specified during
> >> formatting.
> >
> > Which raises a question that has been on my mind for a while...
> >
> > The Debian Installer insists on reformatting any swap partitions it
> > finds, even though that partition, specified by UUID, is probably in
> > use in the /etc/fstab for some other instantiation of Linux -- thus
> > breaking the other Linux, leaving it without a usable swap partition.
> >
> > Would it be possible to either:
> >
> > 1) have the option (default) of *not* reformatting a swap partition
> > or
> > 2) if reformatting is necessary or desired, have the option (default)
> > of preserving the UUID.
> > or
> > 3) using "LABEL=" instead of "UUID=" in fstab for swap partitions, if
> > it turns out to be easier to preserve a LABEL than a UUID.
I am of the opinion that the issue of multibooting under grub and udev
is in need of major rethinking. The /boot/grub/ directory is just too
cluttered to be a tight design, but --- who am I to have any right to
an opinion?
I think the facilities exist for an interested and concerned user to
write labels on all h(is|er) partitions, create a small database of
UUID-Label pairs for all partitions and a script that rewrites the
UUIDs to their prior values and rewrites /etc/fstab to use the old
UUIDs after they have been restored. This would allow the concerned
user to ride out the twists and turns of future revision of this can
of worms.
My contribution to thinking about this is that UUID is crazy overkill
as to uniqueness of tags on partitions. Much better would be an
automatic writing of locally unique labels on any partitions that are
unlabeled. (The ones that are already labeled, are already locally
unique.) The locally unique labels might be the current kernal device
assignment, e.g. sda1, sdb5, etc. i.e. very short and very
mnemonic. For swap, there seems not to be a label field, but the
database could include however many UUIDs as there are swap
partitions, and the rewrite script could match UUID with partition
based on the size of the partition. (Does it really matter is two swap
partition of the same size get their UUIDs swapped during an install
of another OS?) Properly done, this idea could remain invisible to the
developers who insist on using UUIDs.
>
> >From what I've heard, the Ubuntu installer has the same problem,
> and it can ruin a functioning Debian system too. Of course, that's
> not something the Debian installer team can do anything about.
> That's outside of their jurisdiction. But many Ubuntu people, both
> users and developers, are known to monitor Debian's lists. Let's
> hope that some of the right people are listening.
--
Paul E Condon
pecondon@mesanetworks.net
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