Can't Lvcreate when VG is Shared in Oracle 10G RAC

[isaac_loven]

Hi All,
We have 2 new itanium machines running HPUX 11.23. ( ia64 hp server rx2620 ) patched to September 2006 & patches that oracle recommends.
We have installed Oracle 10g RAC ( Real Application Cluster ).
The Volume Group ( vgractst ) is in shared mode.

My question is: HOW DO WE create or extend Lvols in the VG while the the VG is in shared mode?

I am able to to lvcreate, vgextend, and lvextend when I shut down Application, and deactivate the VG on all other nodes. ( then I do a vgexport -p -s -m & then vgimport on the other nodes )

But How do I do this when the VG is shared, as I do not want to shutdown the servers every time I wish to simply add some disk space ?
( Is this a fundermental problem with oracle RACs' on HPUX ? )

I do not believe there is a HW problem.

root@x01 # lvextend -L 1000 /dev/vgractst/system_001
lvextend: The volume group "/dev/vgractst" is active in Shared Mode.
Cannot perform configuration change.


lvcreate -n isaac_test -L 100 vgractst
lvcreate: The volume group "/dev/vgractst" is active in Shared Mode.
Cannot perform configuration change.

INFO:
We have installed HP's ServiceGuard and ServiceGuard Extension for RAC.
T1905BA A.11.17.00 Serviceguard
T1907BA A.11.17.00 Serviceguard Extension for RAC

We have activated our Volume Group in shared mode, and vgdisplay shows the status correctly.
vgchange -S y -c y vgractst ## all nodes

vgchange -a s vgractst ## all nodes.



vgdisplay -v vgractst
--- Volume groups ---
VG Name /dev/vgractst
VG Write Access read/write
VG Status available, shared, client
....
x01 Server
x02 Client

[Steven E. Protter]

Shalom,

Oracle RAC requires volume groups to be activated in shared mode. This disables certain functionality. You will need to stop Oracle RAC and activate the volume group in a non-shared mode to complete the work.

Yes, that means downtime for Oracle.

It's not a bug, its a feature.

SEP

[Duncan Edmonstone · Accepted solution]

Actually if you are on Serviceguard 11.17 there is a way to acheive this whilst keeping Oracle on just 1 node in the cluster online. It's called Single Node Online volume Reconfiguration (SNOR) and requires that you have these patches or newer:

PHCO_33309
PHKL_33312

Have a look at ITRC KB Article KBRC00017735 :

http://www4.itrc.hp.com/service/cki/docDisplay.do?docLocale=en_US&docId=200000082274788

HTH

Duncan

[isaac_loven]

Thanks for the Replies.
Yes Dunken is right, and we have tested it!
RAC needs to be running on one node only first.

Sorry Stephen, you are incorrect - there is a new frature, But I appreciate your effort to assist.

You can also find the doc at:
http://www.docs.hp.com/en/7389/LVM_SNOR_whitepaper.pdf

Summary. The solution is to:
1) Deactivate VG sharing on all execept one node. ( vgchange -a n ), after shuting the application.( crsctl stop crs )
2)On the node that is still operating, change the VG form shared to exclustive. ( it remaines active).
3) Do the lvcreate/vgextend/lvextends.

4) Do vgexport/vgimport map if lvcreate or vgextend was done.
5) change the VG back to shared on other machines.
6) start App on other nodes: ( crsctl stop crs )

vgchange(1M)
A new option (-x) was added to the vgchange command to change the activation mode of a shared volume group.
Changing the mode to exclusive from shared
vgchange -a e -x vg_name

Thanks, Isaac