help with plan to add VG for migrating oracle data

[John Kittel]

HP-UX 11.11. ServiceGuard A.11.14. Oracle 9.2.

I need more space for oracle data. I can't add PV to the VG because max PV per VG has been reached. I can't afford the down time to recreate the VG with greated PV per VG.

Will it work to create a second volume group, and reconfigure ServiceGuard to use 2 volume groups in the oracle package, with some of the oracle data on logical volumes in one VG, and other oracle data in logical volumes in 2nd VG? Also, after creating 2nd VG, can I move oracle data from one VG to the other? Can the data be moved by using lvextend to create a mirror from PVs in VG01 to PVs in VG02?

[Ivan Krastev]

> I need more space for oracle data. I can't add PV to the VG because max PV per VG has been reached. I can't afford the down time to recreate the VG with greated PV per VG

Do you have space in cluster VG with size at least the smallest PV size? If yes, you can remove one PV and add bigger.

regards,
ivan

[James R. Ferguson]

Hi John:

> Can the data be moved by using lvextend to create a mirror from PVs in VG01 to PVs in VG02?

No. LVM mirroring is done at the *logical volume* level. Since a logical volume belongs to a volume group, you can't mirror from one volume group to another.

Regards!

...JRF...

[Tim Nelson]

You are out of luck in this case.

Two options ( both require outage )

1) create a new vg and new lvol that could be mounted underneath the origional mount and move data to it then delete the origional data

2) Create a new VG with plenty of MAX_PE and MAX_PV. Mirgrate all data to this new VG. Delete the old one when done.

[John Kittel]

OK, I am clear that I can't lvextend LV mirror from VG01 to VG02.

But I'm not sure from responses so far, so I will ask again,...

Is it possible to have two VG in oracle ServiceGuard cluster, with some oracle data in VG01 and some in VG02?

If it is possible, then can I move data from one LV in VG01 to another LV in VG02, using for example fbackup/frecover with oracle shut down, then remount new LV onto original mount point?

Also, Ivan suggested install larger PV in VG01. Disks are in DS2405 Fiber Channel enclosures. Can there be two diffferent capacity disks in one DS2405, in same VG?

- John

[Matti_Kurkela · Accepted solution]

- "Is it possible to have two VG in oracle ServiceGuard cluster, with some oracle data in VG01 and some in VG02?"

Yes, definitely possible.

- "If it is possible, then can I move data from one LV in VG01 to another LV in VG02, using for example fbackup/frecover with oracle shut down, then remount new LV onto original mount point?"

Yes. Remember to edit the package control script to change the LV mounting configuration to match the new situation - in all cluster nodes.
(When changing something in a cluster, our most common mistake is forgetting to copy the changes to _all_ the other nodes when necessary. The package control scripts are not replicated automatically.)

- "Also, Ivan suggested install larger PV in VG01. Disks are in DS2405 Fiber Channel enclosures. Can there be two different capacity disks in one DS2405, in same VG?"

If the VG's "Max PE per PV" value allows larger capacity than the current PVs, then yes.
(Even if the Max PE per PV value matches the size of the current PV, you technically *can* add a larger disk but cannot use its full capacity, so you gain nothing.)

MK

[John Kittel]

xcellent! Thanks everyone. I will leave thread open for a while in case there are further suggestions, but my questions are essentially completely answered.

[John Kittel]

thanks again. closed.