Adding alternate path uisng pvlinks

[Bob Manocchia]

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

[Torsten.]

use vgextend only, pvcreate will destroy your data.

[Bob Manocchia]

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.

[James R. Ferguson]

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...

[Bob Manocchia]

Thanks everyone.

[Bob Manocchia]

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.