topic Re: two servers share VA7400 Disk Array in Operating System - HP-UX

two servers share VA7400 Disk Array

Carol Yu — Tue, 12 Oct 2004 14:36:06 GMT

Hi, All,

I have two servers (rp5470) as a cluster (active-active) running MC ServiceGuard and sharing one VA7400 Disk Array.

How could I know that the disk I want to setup a new vg on one server is not being used by the other server?

Thanks a lot,
Carol

Re: two servers share VA7400 Disk Array

RAC_1 — Tue, 12 Oct 2004 14:50:06 GMT

You will have to check the file /etc/lvmtab on both servers. (strings /etc/lvmtab)

This would help you if the controller instances are same on both servers, else you will have to use diskinfo command on the disk you intend to use and compare the sizes.

Say on one node /dev/dsk/c1t2d0 is there and on another it is /dev/dsk/c2t2d0, then run diskinfo on both and compare the sizes.

Also if you use pvcreate on it, it will give you a message that it is already been used if any.

This becomes quite easy with secure path. It iwll give all the details about a PV.

Anil

Re: two servers share VA7400 Disk Array

Tim D Fulford — Tue, 12 Oct 2004 14:50:28 GMT

Hi

1 - armdsp -L & check out what LUNs are configured on the array.

2 - ioscan -fknCdisk on BOTH servers.

3 - basically you ned to be able to count in base 8, as the LUN target (t) & destination (d) will be in the HW path & device path.
LUN0 --> 0.0, t=0, d=0
LUN1 --> 0.1, t=0, d=1
:etc:
LUN7 --> 0.7, t=0, d=7
LUN8 --> 1.0, t=1, d=0
LUN9 --> 1.1, t=1, d=1
and so forth.

4 - ting the above together; on the two servers from the ioscan results you should see that the disks are called /dev/dsk/c?td so that say on server A /dev/dsk/c6t0d3 (LUN3) will actually be the same as /dev/dsk/c10t0d3 on server B; similarly their hardware paths will end .0.3

Regards

Tim

Re: two servers share VA7400 Disk Array

Carol Yu — Fri, 15 Oct 2004 13:03:30 GMT

Thanks a lot for your reply.

Re: two servers share VA7400 Disk Array

Carol Yu — Fri, 15 Oct 2004 13:05:49 GMT

I was trying to submit points and got "system unavailable" error and failed. Sorry! Will try again later.