copying lvm with the same name

[Aldo Foot]

On Fri, Mar 20, 2009 at 1:39 PM, jdow <jdow at earthlink.net> wrote:
> From: "Dr. Michael J. Chudobiak" <mjc at avtechpulse.com>
> Sent: Thursday, 2009, March 19 05:10
>
>
>> Frank Cox wrote:
>>>
>>> It looks like the machine can see the second drive and the lvm that's on
>>> it
>>> /dev/sdb2, but it has the same VolGroup name as /dev/sda2.
>>
>> Yes, this is common and annoying. Here is the guide that I followed when
>> it happened to me:
>>
>> http://www.whoopis.com/howtos/linux_lvm_recovery.html
>>
>> I filed bug 461682 (https://bugzilla.redhat.com/show_bug.cgi?id=461682),
>> requesting that the default volume names not be so generic - they now
>> incorporate the hostname, so this problem should be much less common in
>> F11+.
>
> That's a wrong solution. GUIDs were invented to handle this sort of problem.
> Suppose "Fred" has a machine he called "boundless". He has a disk problem.
> He asked "Judy" to fix it. And for unknown reasons "Judy" also has a machine
> called "boundless". GUIDs to the rescue.

Hmm... The wrong solution? *It is* the solution because I actually used the
advice given in this thread to fix a system.
I don't think I understand how hostnames or GUIDs figure in this kind of
situation. If you have the time, would you share with us how you've done it?


> The only time GUIDs will fail is when you use "dd" to create as good a
> back-up
> as you can of a dying disk. Sometimes this is a bad thing, as in the
> scenario
> under discussion. Sometimes it is a good thing, as when I performed that
> sort
> of a recovery on an NTFS laptop drive. I didn't even have to reinstall
> anything
> after NTFS chkdisk massaged the drive. (It had a directory block it could
> not
> update - on the "C:" drive.)
>
> Sadly GUIDs are too complicated for the people naming disk partitions.

In this particular LVM case, we've looked at UUIDs as they refer to Logical
Volumes, which are not disk partitions. They are not the same thing.

~af