Sancopy LVM

[Ehrler]

Hello,

I have a Question about VGID and PVID.
I make a SANCOPY (EMC)from Node 1 to Node 2.
Node 1 -> vgdata; Node 2 -> vg_data
After Synchronizing, we make a vgexport with Mapfile and Option -s on Node 2 (vg_data). Copy the Mapfile from Node 1 to Node 2 and make a vgimport with mapfile and option -s. On Node 2 the VGID and the PVID are the same. How does it work's. ?? Thanks

[Steven E. Protter]

Shalom Ehrler,

I would use a mapfile -m option in export/import.

I can't give an opinion on sancopy commands. I'd back up the data before tyring this.

SEP

[James R. Ferguson · Accepted solution]

Hi:

The EMC utility copied the LVM header from one disk to the other, replicating the VGID and PVID of the source disk.

A 'mapfile' is primarily used to assign *logical volume* IDs in lieu of defalt ones like 'lvol1', 'lvol2', etc. The use of the '-s' switch adds (during 'vgexport') the VGID of the volume group which then allows 'vgimport' to match disks to this ID and import them.

This said, there is no problem with having the same PVID and VGID. In reality, these IDs are nothing more than the machine identification number (as seen in 'uname -i') and the timestamp (in Epoch seconds) built when the 'pvcreate' and 'vgcreate' were made.

Regards!

...JRF...

[Chris Hulihan]

It sounds to me like if you need to get them to be different (in case you want to mount both copies on the same server in the future) that you should use "vgchgid" to make the second copy appear as a completely new volume.

i.e. /usr/sbin/vgchgid PhysicalVolumePath [PhysicalVolumePath] ... (check man page for more information).

This changes the ID, and will cause LVM to realize that this is a separate entity, which might be what you're looking for :)

[Ehrler]

Thanks everybody

This are the answer's I searched.

Regards
Ehrler

[Ehrler]

Hello all,

thanks again for the answer.

ok. emc copy the LVM information to device.

But when I make a MirrorView from Clariion
CX700 to CX60 it the same. ?
The host is connected to CX700.
CX700 have problem's (down) so we must switch
to CX600. Can I use the vgimport Option -s
to import the Volume Group. ?

Thanks.
Ehrler