[linux-lvm] metadata too large for circular buffer - any way to increase PV metadatasize?

[Charles Koprowski]

get an up-to-date metadata backup (vgcfgbackup)
pvcreate --restorefile pointing at a copy of that backup file

requesting 0 metadata areas

and specifying the same uuid as it had before
vgcfgrestore from the backup file

This doesn't look like something you can do with the volume group active
[root testnode0 ~]# pvcreate --restorefile san-metadata -u
fTLglk-j1C1-02Z7-8k6l-DTAm-2WNj-9ZGT19 --metadatacopies 0 /dev/hdb -ff
Really INITIALIZE physical volume "/dev/hdb" of volume group "san" [y/n]? y
Can't open /dev/hdb exclusively. Mounted filesystem?
Is that right, or am I missing something?

Hi John,

I know it's been a long time but, Did you found out a solution for this ?

I'm trying to follow the same scenario to increase the metadatasize and got
stuck at the same point.

Thanks

Charles

[Zdenek Kabelac]

get an up-to-date metadata backup (vgcfgbackup)
pvcreate --restorefile pointing at a copy of that backup file

requesting 0 metadata areas

and specifying the same uuid as it had before
vgcfgrestore from the backup file

This doesn't look like something you can do with the volume group active
[root testnode0 ~]# pvcreate --restorefile san-metadata -u
fTLglk-j1C1-02Z7-8k6l-DTAm-2WNj-9ZGT19 --metadatacopies 0 /dev/hdb -ff
Really INITIALIZE physical volume "/dev/hdb" of volume group "san" [y/n]? y
Can't open /dev/hdb exclusively. Mounted filesystem?
Is that right, or am I missing something?
Hi John,
I know it's been a long time but, Did you found out a solution for this ?
I'm trying to follow the same scenario to increase the metadatasize and got
stuck at the same point.

Hi

I've no real idea what's the original problem - but here is clear error on
user side. This message:

"Can't open /dev/hdb exclusively. Mounted filesystem?"

indicates that device is NOT UNUSED and it has to be unused for this operation
- i.e. you MAY NOT run this operation while there are active LVs from this PV
(one of possible reasons why 'hdb' cannot be opened exclusively)



To increase 'metadata' size - you ether have to add some NEW PV with
much bigger metadata size space (and such operation still needs some
extra space to proceed with existing size). Then disable existing metadata
areas - so you will end-up of storing bigger MDA only to this new bigger MDA
on a new PV - note - it's quite risky plan to leave MDA only on single PV in
multi-PV VG - so I'd not advice this for any serious use.

You may PV via pvmove to a new bigger PV.
(adviced operation - though it may take its time...)

There is NOT lvm2 native support for 'online' resize of PV mda size - and
while it's possible to do this operation manually - it's quite complex task -
so I'd not advice to do this either - unless you have FULL backup of everything.

So back to your original problem - please describe EXACTLY what is your
problem and attach outputs of pvs,vgs,lvs and what you want to achieve.


Regards

Zdenek

[Charles Koprowski]

Post by Zdenek Kabelac

get an up-to-date metadata backup (vgcfgbackup)
pvcreate --restorefile pointing at a copy of that backup file

requesting 0 metadata areas

and specifying the same uuid as it had before
vgcfgrestore from the backup file

This doesn't look like something you can do with the volume group active
[root testnode0 ~]# pvcreate --restorefile san-metadata -u
fTLglk-j1C1-02Z7-8k6l-DTAm-2WNj-9ZGT19 --metadatacopies 0 /dev/hdb -ff
Really INITIALIZE physical volume "/dev/hdb" of volume group "san" [y/n]? y
Can't open /dev/hdb exclusively. Mounted filesystem?
Is that right, or am I missing something?
Hi John,
I know it's been a long time but, Did you found out a solution for this ?
I'm trying to follow the same scenario to increase the metadatasize and got
stuck at the same point.

Hi
I've no real idea what's the original problem - but here is clear error
"Can't open /dev/hdb exclusively. Mounted filesystem?"
indicates that device is NOT UNUSED and it has to be unused for this
operation - i.e. you MAY NOT run this operation while there are active LVs
from this PV (one of possible reasons why 'hdb' cannot be opened
exclusively)

Hi Zdenek,

I'm running a 5 nodes XEN dom0s cluster which uses a shared VG and few
hundreds LVs to store virtual machines disks.

As we were running out of space in the actual VG, I was about to add a new
PV and take the opportunity to increase the metadata size as you described
below.

I was wondering if I could run the "pvcreate --restorefile --metadatacopies
0" while the VG (and PV) were online.

Now I got the answer :-)

Thank you !

Charles

Post by Zdenek Kabelac
To increase 'metadata' size - you ether have to add some NEW PV with
much bigger metadata size space (and such operation still needs some
extra space to proceed with existing size). Then disable existing metadata
areas - so you will end-up of storing bigger MDA only to this new bigger
MDA on a new PV - note - it's quite risky plan to leave MDA only on single
PV in multi-PV VG - so I'd not advice this for any serious use.
You may PV via pvmove to a new bigger PV.
(adviced operation - though it may take its time...)
There is NOT lvm2 native support for 'online' resize of PV mda size -
and while it's possible to do this operation manually - it's quite complex
task - so I'd not advice to do this either - unless you have FULL backup of
everything.
So back to your original problem - please describe EXACTLY what is your
problem and attach outputs of pvs,vgs,lvs and what you want to achieve.
Regards
Zdenek
_______________________________________________
linux-lvm mailing list
https://www.redhat.com/mailman/listinfo/linux-lvm
read the LVM HOW-TO at http://tldp.org/HOWTO/LVM-HOWTO/