topic Re: Help with disks in Operating System - HP-UX

Help with disks

Coolmar — Wed, 19 Dec 2007 19:17:56 GMT

When I do an ioscan on the host system, there are around 100 LUNs. 46 of those LUNS are designated to various VMs/guests. However, the rest are unaccounted for. I know there are some that are unassigned but there shouldn't be this many. The guy who keeps track of all this went on vacation and we don't see any docs on it. Is there a way for me to determine where the other disks are assigned (which I doubt) or is there a way to even find out if the disk is being used? I tried the fstyp -v /dev/dsk/device on a disk that is being used by a VM, but at the host level it tells you nothing....and I need to work at the host level. I doubt there is a way without involving SAN people or finding the docs, but I just thought I would pose this in case there is a way.

Thanks,

Re: Help with disks

Sandman! — Wed, 19 Dec 2007 19:23:05 GMT

For starters could you post the output of ioscan on your system.

# ioscan

~cheers

Re: Help with disks

melvyn burnard — Wed, 19 Dec 2007 19:24:26 GMT

well to see what devices are used by any HP Virtual Macjhines, you can use the hpvmdevmgmt -l all command
man hpvmdevmgmt

Re: Help with disks

Coolmar — Wed, 19 Dec 2007 19:28:29 GMT

The ioscan is really really big and basically just lists all the disks and devices.

I have already used hpvmstatus to determine which disks are assigned to VMs. It is the disks that *don't* seem to be assigned to VMs that I am trying to figure out if they are being used.

Re: Help with disks

Tim Nelson — Wed, 19 Dec 2007 19:31:25 GMT

Also beware that if multipathing is involved you may not really have 100 luns. It may be 2,6,8... paths to the same luns.

In a IVM environment there are three ways to use these devices so the best resource to use is hpvmdevmgmt, keep in mind it will not show the resources used by the VM Host.

As you stated, good up to date documentation is a must or at least some admin scripts that identify your resources and usage assignments. These are typically a collection of the 10 or so commands used to format and organize your config in a way that you can quickly find what you are looking for.

Re: Help with disks

melvyn burnard — Wed, 19 Dec 2007 19:45:50 GMT

you could also check what Volume Groups you have, and see what devices belong to them, using :
strings /etc/lvmtab
and also
vgdisplay -v vgname

Re: Help with disks

Coolmar — Wed, 19 Dec 2007 19:47:47 GMT

Melvyn....strings and vgdisplay will not tell you anything. They will only at the *guest* level, and I already know what disks belong to the guests. I am at the host level and the only disks assigned to the host are the two internal disks assigned to vg00.

Re: Help with disks

melvyn burnard — Wed, 19 Dec 2007 19:54:03 GMT

well those commands will IF you had other vg's in use, as I commented.
Looks like you have been caught out by a lack of documentation, but if you have the Virtual Machine Manager set up you could take a look at the Storage Tab and see what that shows you in use fo rthe VM's. If a disk is not shown as used by a VM, or the host, then it is highly probable it is unused.
But this is an assumption that must be taken with care.

Re: Help with disks

Hoang Chi Cong_1 — Thu, 20 Dec 2007 03:49:29 GMT

Hi Coolmar,

I just have some hints for you:

First of all, you can find out pv was created from which storage device like: VA, EVA....

For example:

All LUN that create from VA will have the discription like: Axxxxx, from EVA will have the discription like HSV100, HSV200, etc....

Then you can use command diskinfo or pvdisplay to check out which volume group it belong to....

Hope this helps
Hoang Chi Cong

Re: Help with disks

Coolmar — Thu, 20 Dec 2007 15:10:47 GMT

Thanks everyone....my only option seems to be to use pvcreate WITHOUT the -f switch....it lets me know if the disk belongs to a volume group. Can't find out which vg on which guest, but at least I can find out if the disk is used or not.