topic Re: Determine if quorom is set or not in Operating System - HP-UX

Determine if quorom is set or not

Dhr. Ron van Eijk — Thu, 22 May 2003 11:29:29 GMT

L.S.

How can we show the status of the quorum in a volume group. It is settable through lvchange -q y/n, but *how* can we *read* it? This is not only valid for the boot volume (vg00), but also for any other volume group. The lifcp /dev/rdsk/:AUTO - does not do it...

Re: Determine if quorom is set or not

Ken Hubnik_2 — Thu, 22 May 2003 11:54:08 GMT

It is the -lq parameter passed to the hpux kernel loader.

mkboot -a "hpux -lq (;0)/stand/vmunix" /dev/dsk/cxtxdx

Re: Determine if quorom is set or not

Massimo Bianchi — Thu, 22 May 2003 11:58:02 GMT

Hi,
at boot you disable qorum with

hpux -lq (;0)/stand/vmunix

and in general you can change the activation with the vgchange -a y -q y|n .

If you want to konw the status, simply look at vgdisplay -v. If there are missing disk, you will find.

By default quorum is ALWAYS required, unless specified (-q n ).
Answer can also be found in the man page:

-q quorum Set the quorum enforcement for each specified
volume group. quorum can have one of the

Hewlett-Packard Company - 4 - HP-UX Release 11.00: October 1997

Standard input

following values:

y Enforce the quorum requirement.
This is the default.

HTH,
Massimo

Re: Determine if quorom is set or not

Dhr. Ron van Eijk — Thu, 22 May 2003 12:01:14 GMT

Hello, Ken,

This is *not* what we mean. We don't want to make this volume 'bootable', but we want to know/show and not change this setting (comparable with AIX 'lsvg anyvg'), there is a line, saying: QUORUM: n.

Gert Leerdam

Re: Determine if quorom is set or not

Bernhard Mueller — Thu, 22 May 2003 12:04:10 GMT

Hello,

Hello,

not sure what you mean but I guess it is that
you can activate a VG without quorum being present by:
vgchange -a y -q n vgXYZ

vgdisplay vgXYZ
will give you two numbers of disks:
Cur PV
Act PV

if you regain your "lost" disks in the VG you have to activate it again to recover links too previously missing disks. simply enter
vgchange -a y vgXYZ

if you have access to all disks that belong to the VG, then Cur PV = Act PV.

Regards,
Bernhard

Re: Determine if quorom is set or not

Marco Santerre — Thu, 22 May 2003 12:08:43 GMT

Quorum can be changed at the Volume Group level, but it is not a variable that you set for the Volume Group, it is an option that you can use to activate a Volume Group that may have problems activating all the PVs in the Volume Group.

Re: Determine if quorom is set or not

Dhr. Ron van Eijk — Thu, 22 May 2003 12:20:49 GMT

Thanks for all the answers so far, but it is *not* what we mean. Setting the quorum is comparable to saying LET A=1, and knowing what A contains is saying PRINT A. So, how can we READ the *current* quorum value, and not *change* or *set* it.

Re: Determine if quorom is set or not

Marco Santerre — Thu, 22 May 2003 12:24:41 GMT

As I mentionned before, it is ONLY something you can change when trying to activate a Volume Group therefore it is not a variable that you can set and display afterward. The quorum flag will *only* help you activate a volume group. You can check man vgchange to see the -q option and the explanation as to what it does.

Re: Determine if quorom is set or not

Dhr. Ron van Eijk — Thu, 22 May 2003 12:44:35 GMT

Hello, Marco,

Thank you for your answer(s). It seems to be, that you are right. It's a pity, that you cannot check what is the setting of the quorum value. We had a machine, that was rebooted, and then the vg03 did not work anymore. After setting the quorum to No, the volumes could be mounted again. But we could never read the value.

Thanks,
Gert Leerdam

Re: Determine if quorom is set or not

James R. Ferguson — Thu, 22 May 2003 12:46:06 GMT

Hi:

Interesting question. The quorum information is maintained in the VGRA (Volume Group Reserved Area) where, among many things, the VGID can be found.

Perhaps someone from HP could provide the specific address that we could interrogate.

Regards!

...JRF...

Re: Determine if quorom is set or not

Jean-Louis Phelix — Thu, 22 May 2003 13:07:18 GMT

Hi,

The problem is that quorum on hp-ux is only a flag used at activation (and not a value that we could choose). So I can't see any reason to reserve a field in the VGRA for this flag.

I think that the value you are looking for is simply the hp-ux rule : more than 50% of the number of disks ...

So having a look at cur PV against act PV in the vgdisplay output will give you the reason why your vg couldn't be activated. For example having lost 1 disk on a 2 disks vg means that you haven't met the quorum. This is only checked at activation time.

Regards.