Re: arbitrary disk name assignment affects dump/restore
On 20110417_111214, Andrei Popescu wrote:
> On Sb, 16 apr 11, 15:00:39, Dean Allen Provins, P. Geoph. wrote:
> >
> > This means that I must NOT rely on my automatic (crontab-based) dump
> > scripts, but interrogate the system manually, and if necessary, alter
> > /var/lib/dumpdates so that the script will run properly.
>
> No, just adapt your script to use whatever symlink you like in one of:
>
> /dev/disk/by-id/
> /dev/disk/by-label/ # assuming you defined labels
> /dev/disk/by-path/
> /dev/disk/by-uuid/
>
> I prefer labels since they can be set to something meaningful/mnemonic.
>
> > This is a REAL PAIN.
>
> Yes and no. On one hand it is a change in behaviour, OTOH, relying on
> the specific order in which devices are seen by the kernel just asks for
> trouble. You only need consider removable drives.
>
> > Is it possible that /etc/fstab, which now identifies the partitions on my
> > single fixed disc via UUID labels, is an unwilling participant in this
> > confusion?
>
> No
>
> > Should I alter /dev/fstab to indicate the partitions as it was done before
To Dean,
Surely you mean /etc/fstab ;-)
You can alter /etc/fstab in a way that I have found useful for old
farts like me:
Write a label every partition on every hard disk that was referred to
(in the good old days) as /dev/hdXd or /dev/sdXd,
where X is a letter like a,b,c, ...
and d id a digit like 1,2,3, ...
Make each label have the form, plXd
where 'pl' is a fixed prefix (mnemonic for 'Partition Label')
and X and d are taken from the good old days.
(And from ls -l /dev/disk/by-uuid/ , see above)
Use the -L option in tune2fs to write these labels.
Then change /etc/fstab to use LABEL=plXd whereever it now uses
UUID="some crazy (but unique) hex string with embedded hyphens"
The important point is that each partition is identified by a
*locally* unique string that contains some internal clues for the
benefit of old farts. (UUID solves the problem of being locally
unique by being locally unique to the biosphere on Earth, which
is, IMHO, overkill.)
Of course, if in future you want to pull one of your hard disks and
install it on in a different computer, you will have to exercise some
caution. You will have to check the /dev/disk/by-* contents and fix
the labels on the disk you are moving to avoid a name clash in the
partition labels, and fix the clash before you make the required new
entries in /etc/fstab of the computer to which the disk is being
moved.
Keep in mind that the partition identifier cannot be constructed
from the mount point because the whole point of /etc/fstab is to
establish a mapping between physical partitions and mount points.
HTH
> > (i.e. /dev/sda1 is /, /dev/sda3 is /home etc.)?
>
> This is likely to make your system un-bootable.
>
> Regards,
> Andrei
> --
> Offtopic discussions among Debian users and developers:
> http://lists.alioth.debian.org/mailman/listinfo/d-community-offtopic
--
Paul E Condon
pecondon@mesanetworks.net
Reply to: