Dne 15. 11. 24 v 21:07 Gionatan Danti napsal(a):
Hi list,
is it possible to import a duplicate VG name from a read-only device?
I know about vgrename, but it needs to update metadata - which is not possible
for read-only device.
I tried to un-manage the host native read/write VG, deleting it from
system.devices, but lvchange -ay shown an error about not being able to create
the /dev/VG/LV symlink (and a "device busy" issue, probably related to the
already-existing symlink). I also tried to activate the specific LV via
lvchange -S lv_uuid, but it shown the same error as above.
In this specific case I put the device in r/w mode and solved the issue with a
plain vgrename. But what if I could not enable writes on the device? Is the
only solution to mount it on a machine without the same VG name (ie: on a live
USB), or can a VG/LV be enabled specifying a different path for the symlink?
Hi
You can always write appropriate lvm.conf filter or use devicesfile to
list only those devices/PV you want to use and not cause 'duplicate VG'
problem for command processing.
However there is no chance to activate duplicated VG/LV as clearly there
cannot exist 2 DM devices with the same name/uuid - they must be unique!
So perhaps maybe you can 'rename' VG of the system you are running from - if
you cannot change the metadata on you read-only device.
Here I'd probably suggest to simply avoid creating such problems upfront,
AKA - if all your systems are using the same VG name and then you want to
'share/swap' such devices between your systems - you should always pick a
unique VG name for each such system. That way avoids all the problems....
Regards
Zdenek
PS: I think ATM lvm2 is already complicated enough to creating some 'overlay'
level of referencing lvm2 names in the system through some 'abstract'
mechanism to solve the issue that can be easily eliminated ahead makes not
much sense to implement....
