topic Re: Adding alternate path uisng pvlinks in Operating System - HP-UX

Adding alternate path uisng pvlinks

Bob Manocchia — Mon, 16 Nov 2009 14:08:12 GMT

I need to add an alternate path to an existing active volume group. I can see the two paths. I need to add the alternate path. My question is do I need to run pvcreate on the alternate path then run vgextend of can I just run vgextend to add the alternate path.

Thanks

Re: Adding alternate path uisng pvlinks

Torsten. — Mon, 16 Nov 2009 14:19:16 GMT

use vgextend only, pvcreate will destroy your data.

Re: Adding alternate path uisng pvlinks

Bob Manocchia — Mon, 16 Nov 2009 14:23:08 GMT

Thanks. The reason I asked was that HP first line told me to run pvcreate. It didn't make sense to me but I had difficulty adding the paths without running pvcreate but I think my problem is elsewhere.

Re: Adding alternate path uisng pvlinks

James R. Ferguson — Mon, 16 Nov 2009 14:24:41 GMT

Hi Bob:

Alternate LVM links (otherwise known as 'pvlinks') are simply additional paths to the same physical disk. Therefore, you don't need nor would you want to run a 'pvcreate'.

The first path defined for a particular physical disk (during a 'vgcreate') is the "primary" link. Thereafter, additional paths are "secondary" links. Often, such secondary links are added with a 'vgextend'. A 'vgdisplay" will show the primary and secondary links. Examining '/etc/lvmtab' will show the same order since that is where the definition of a "primary" link begins.

To promote a secondary path to primary, simply 'vgreduce' the primary link and then 'vgextend' it back into the volume group again.

Regards!

...JRF...

Re: Adding alternate path uisng pvlinks

Bob Manocchia — Mon, 16 Nov 2009 14:33:46 GMT

Thanks everyone.

Re: Adding alternate path uisng pvlinks

Bob Manocchia — Mon, 16 Nov 2009 14:36:25 GMT

Thanks for the info. Like I said I think my problems are elsewhere. I can see what I think are the alternate paths but I cannot add them.