topic Re: Remove Alternate path in Operating System - HP-UX

Remove Alternate path

Christine Nguyen — Thu, 23 Mar 2006 16:10:13 GMT

I have VGs and using PVlink, I want to remove
the alternate link.

In vgdisplay:

--- Physical volumes ---
PV Name /dev/dsk/c15t0d3
PV Name /dev/dsk/c16t0d3 Alternate Link
PV Name /dev/dsk/c16t0d4
PV Name /dev/dsk/c15t0d4 Alternate Link

In lvmtab:

/dev/vg02
/dev/dsk/c15t0d3
/dev/dsk/c16t0d4
/dev/dsk/c16t0d3
/dev/dsk/c15t0d4

If I do:

#vgreduce /dev/vg02 /dev/dsk/c16t0d3
#vgreduce /dev/vg02 /dev/dsk/c15t0d4
#vgreduce -f /dev/vgqas02

then do strings lvmtab, I'll see 2 primary disks only:
/dev/vg02
/dev/dsk/c15t0d3
/dev/dsk/c16t0d4

Please advise the right procedure to remove the alternate link.

Thanks.

Re: Remove Alternate path

A. Clay Stephenson — Thu, 23 Mar 2006 16:17:17 GMT

Except for this step from out of the blue:
vgreduce -f /dev/vgqas02
you did everything correctly although it's unusual to remove alternate links -- if they are still valid.

Re: Remove Alternate path

Christine Nguyen — Thu, 23 Mar 2006 16:34:19 GMT

Typo error, should be:
#vgreduce -f /dev/vgs02

Re: Remove Alternate path

Christine Nguyen — Thu, 23 Mar 2006 16:34:52 GMT

Typo error, should be:
#vgreduce -f /dev/vg02

Re: Remove Alternate path

A. Clay Stephenson — Thu, 23 Mar 2006 16:39:50 GMT

You don't need that step.

Re: Remove Alternate path

James R. Ferguson — Thu, 23 Mar 2006 16:41:44 GMT

Hi Christine:

Typographical error or not, there is no need to do 'vgreduce -f'.

Eliminating an alternate (pvlink) is as simple as doing the 'vgreduce '.

Usually, you remove the *primary* link, which promotes the *alternate* link to a primary, and then 'vgextend' the former primary link thereby adding it as the new alternate link. This is the method by which you swap primary and alternate links to achieve path balancing.

Regards!

...JRF...

Re: Remove Alternate path

Christine Nguyen — Thu, 23 Mar 2006 16:50:00 GMT

I used pvlink to balance the load in the emc storage array, because of the powerpath s/w requires no pvlink, therefore I need to remove all alternate paths. So I don't need to do the last cmd ?

Re: Remove Alternate path

James R. Ferguson — Thu, 23 Mar 2006 17:02:40 GMT

Hi Christine:

If by the "last command" you mean the 'vgreduce -f', then no.

See the 'vgreduce' manpages for more information.

Regards!

...JRF...