topic Re: Creating physical volume groups? in Operating System - HP-UX

Creating physical volume groups?

Matt Harrell — Mon, 22 Apr 2002 19:51:25 GMT

With my upcoming reinstallation of HP-UX 11.0, I want to use PVG-strict mirroring. I plan on mirroring the two internal hard disks for the root disk, and set up two PVG's for the disks in the external cage. There will be 4 disks on each side of the cage. I want to make each side one PVG (pvg01 and pvg02), and then make all of the disks in the case belong to one volume group ("vgplexus"). I'm not totally sure how to do this.

Assume that the device files for the hard disks are c1t3d0, c1t4d0, c1t5d0, c1t6d0, c1t7d0, c1t8d0, c1t10d0, c1t11d0. What I think I need to do is this:

# pvcreate -f /dev/rdsk/c1t3d0
(for each disk)
# mkdir /dev/vgplexus
# mknod /dev/vgplexus/group c 64 0x010000
(making that number unique)
# vgcreate ???g pvg01 /dev/vgplexus /dev/dsk/c1t3d0 /dev/dsk/c1t5d0 /dev/dsk/c1t7d0 /dev/dsk/c1t10d0
# vgextend ???g pvg02 /dev/vgplexus /dev/dsk/c1t4d0 /dev/dsk/c1t6d0 /dev/dsk/c1t8d0 /dev/dsk/c1t11d0

and then continue on with the lvcreates, etc.

It's those vgcreate and vgextend commands I'm really not sure about.

Re: Creating physical volume groups?

S.K. Chan — Mon, 22 Apr 2002 19:57:04 GMT

# vgcreate ???g pvg01 /dev/vgplexus /dev/dsk/c1t3d0 /dev/dsk/c1t5d0 /dev/dsk/c1t7d0 /dev/dsk/c1t10d0
# vgextend ???g pvg02 /dev/vgplexus /dev/dsk/c1t4d0 /dev/dsk/c1t6d0 /dev/dsk/c1t8d0 /dev/dsk/c1t11d0

Both the command looks good ! After you're done (before you create your LVs) you would want to check /etc/lvmpvg file to make sure the disks are in the PVGs and in the right order as you intended them to be.

Remember to use th "-s g" option in your lvcreate to enable PVG-strict mirroring. for example ..
# lvcreate -L 1200 -m 1 -s g -n lvol1 /dev/vgplexus

Re: Creating physical volume groups?

steven Burgess_2 — Mon, 22 Apr 2002 20:12:35 GMT

Hi Matt

Have a look at the following doc

Regards

Steve

Re: Creating physical volume groups?

James R. Ferguson — Mon, 22 Apr 2002 21:27:32 GMT

Hi Matt:

I too like the ease of maintenance that Physical Volume Groups offers. I'd offer one additional setup criteria -- when you do your 'vgcreate' specify some appropriate values for 'max_pe', 'max_pv', etc. Don't simply let these attributes default. Remember that once set these attributes cannot be changed without recreating the volume group. Therefore, plan for the future, especially given the versatility PVGs offer.

Regards!

...JRF...

Re: Creating physical volume groups?

Matt Harrell — Wed, 24 Apr 2002 12:12:31 GMT

Excellent. Thank you very much everybody!