topic Re: vgchange query in Operating System - HP-UX

vgchange query

BFA6 — Tue, 11 Dec 2001 11:45:13 GMT

Hi,

We have a 2 node ServiceGuard cluster with shared disk in 2 SC10's with alternate links to the primary & mirror disks.
In the package control script, should I be activating the volume groups with no quorum ?

Thanks in advance.

Hilary

Re: vgchange query

Madhu Sudhan_1 — Tue, 11 Dec 2001 11:56:48 GMT

Hilary Nicholson :

You need to edit /etc/lvmrc and ensure that only root volume group gets activated upon system boot up. In the package control script you shoulld activate the volume group in exclusive mode that is vgchange -a e /dev/vg0X. This 'e' option works only when the volumegroup is made clusteraware. i.e., vgchange -c y /dev/vg0X.

Hope this helps.

-Madhu

Re: vgchange query

Duncan Edmonstone — Tue, 11 Dec 2001 12:05:47 GMT

That depends mainly on the number of disks in your volume group - if you have only two disks in your volume group then the failure of a single disk will prevent the volume group from activating, and you might want to consider disabling the requirement for quorum. Otherwise leave it on.

HTH

Duncan

Re: vgchange query

Santosh Nair_1 — Tue, 11 Dec 2001 13:39:46 GMT

You shouldn't have to activate the VGs at all. MC/SG should be activating the volume groups. Make sure to edit /etc/lvmrc to activate only the non-SG VGs (see MC/SG manual for more details). Also, you should only activate without quorum if one (or more) of the disks in your VG is no longer active or is having problems.

Hope this helps.

-Santosh

Re: vgchange query

BFA6 — Tue, 11 Dec 2001 14:06:04 GMT

Hi,

OK ServiceGuard is activating the VG's in the package control script.
We had power issues, so machines rebooted, a BCC failed in one of the SC10's so we lost the primary disks. However for some reason we also lost 3 of the alternate paths, so when ServiceGuard tried to start the package it couldn't activate the VG's as quorum wasn't present. So should ServiceGuard activate the VG's with no quorum ?

Hilary

Re: vgchange query

Sanjay_6 — Tue, 11 Dec 2001 16:07:54 GMT

Hi Hilary,

you should activate your cluster VG without quorum if exactly half of your configuration is powered from a source different than the other half. The only reason, you do a vgchange without quorum is so that you can still bring the VG up in case half of the total no of disks are offline. If you want to have a quorum, you should have half + 1 disk atleast to activate the VG. It is a choice to be made by the SA for that system / configuration.

Hope this helps.

Regds