topic Re: SG installation in Operating System - HP-UX

SG installation

Dmitry Stepanyuk — Wed, 08 Aug 2001 07:37:31 GMT

I must install SG on 2 servers HP9000 L-class with 2 internal disks in each and FC60 disk array as shared space. The servers have bought about 1 year ago with factory installation. I tryed to install SG and have error about incorrect disk configuration. First server cann't access to internal boot disk with VG00 on the second server and vice versa. I think problem is same VGID on the internal disks. I cann't re-install any servers. I try to use 'vgchgid' command, but unsuccessful because it working with EMC or XP arrayes only. What can I do???
How can I change VGID on the internal disk??

Re: SG installation

Eberardo Pipani_1 — Wed, 08 Aug 2001 07:44:47 GMT

Hi,

How to change VGID on vg00:

1st metod:
SG will think that a VG is on the shared bus if it can see the identical volume group id (VGID) on two different nodes. This is usually a good assumption, if the machines were installed in a supported way. ;)

What we often see (and do not support) is that customers clone their disks with tools like dd(1m) or with copyutil (in the offline diagnostic). Also cloned disks created by hardware mirroring (e.g. EMC BCVs) are often seen. The common scenario is then that the LVM header is the same on the boot disks, thus confusing SG as the VGID is now the same.

The only way to get rid of this, is to change the VGID of one of the VGs by doing the following:

- boot one machine to maintenance mode (hpux -lm)
- vgchgid -f /dev/dsk/ /dev/dsk/ ..
(include all disks of vg00 in this command, -f (force) option is undocumented)
- vgexport vg00
- mkdir /dev/vg00
- mknod /dev/vg00/group c 64 0x0
- vgimport /dev/vg00 /dev/dsk/... /dev/dsk/..
- reboot

If the above scenario does NOT describe your situation, you may want to check the following:

- Has the /etc/lvmtab been copied from one node to the other?
In this case you should also follow the same procedure above (vgexport/vgimport in maintenance mode), but NOT run vgchgid (since only the lvmtab contains the wrong VGID, but the LVM header of the disks is ok)

- For specific diskarrays (e.g. Nike diskarray) SG checks the serial number. The serial numbers must be different. This can be checked by your h/w support. If the serial numbers of two diskarrays are the same, it can have a similar effect.

2nd metod
Use make_recovery, because make_recovery rebuld the correct VGID.

Eberardo

Re: SG installation

Marcin Wicinski — Wed, 08 Aug 2001 07:45:54 GMT

Hi Dmitry,

Please specify exactly the error message you get while installing SG.

Re: SG installation

John Waller — Wed, 08 Aug 2001 13:18:49 GMT

Dmitry,

The problem is definatly NOT with the VGID on the two servers. In all our ServiceGuard installations each pair of servers, the software has been loaded identically, the only change we have made to the servers is changing the SCSI ID on the controller on one server from 7 to 6 so you don't have any conflicting SCSI ID's on a bus. Are you sure that the problem was with the internal boot disk? I sometimes have an error relating to the DVD/CD ROM drive, a message simmilar to can not identify disk ID of device /dev/dsk/c1t2d0.

Re: SG installation

John Waller — Wed, 08 Aug 2001 13:26:45 GMT

Dmitry,
Re-reading you question I have to ask which VG does the aplication you are serviceguarding live. You cannot serviceguard an application using VG00 (root volume group). When using Serviceguard you have a VG available in exclusive mode (only seen by one system) of cause this can not be done with the root VG or else how would the redundent system run an O/S