topic Re: query on shared mode in cluster env in Operating System - HP-UX

query on shared mode in cluster env

himacs — Thu, 14 Oct 2010 13:51:10 GMT

Hi Admins,

I need some clarifications on shared mode.

1.To activate a VG in shared mode,we need to execute vgachange -S y first..?
2.On what circumstances we have to activate VG as shared ?

I think only with active-active cluster.So that both the system will be having read-write access on VG.

Regards
himacs

Re: query on shared mode in cluster env

melvyn burnard — Thu, 14 Oct 2010 14:34:49 GMT

You need to be careful with your wording here.
There is LVM Exclusive mode (vgchange -c y and then vgchange -a e) for Serviceguard,
and then there is LVm Shared mode (also known as SLVM) which is enabled when you install SGeRAC.
This allows you to set the mode to S, as in vgchange -a S, and this allows the VG to be activated in Shared mode, in other wiords in read/write mode on multiple nodes.

Re: query on shared mode in cluster env

shanmuhanandam — Fri, 15 Oct 2010 06:31:06 GMT

Hi,

yes, you need to run the "vgchange -S y" for activating the vg in shared mode.
But if you have installed Service guard ext for RAC, then only you can activate the Vg's in shared mode.

Regds,
Shan,