topic Physical Volume Existence in Operating System - HP-UX

Physical Volume Existence

Cliff Lim Kok Hwee — Tue, 12 Oct 2004 21:39:39 GMT

Gd Day Forum,

I need to check whether a particular harddisk is already having Physical Volume created on it.

I run the command,
#pvdisplay /dev/dsk/c0t5d0
pvdisplay: Couldn't find the volume group to which
physical volume "/dev/dsk/c0t5d0" belongs.
pvdisplay: Cannot display physical volume "/dev/dsk/c0t5d0".

Query: Other then this command, any other command to double confirm?

regards/cliff

Re: Physical Volume Existence

Sridhar Bhaskarla — Tue, 12 Oct 2004 21:45:12 GMT

Hi Cliff,

Do 'strings /etc/lvmtab |grep c0t5d0'. You shouldn't get any output.

If the VG is inactive, then 'pvdisplay' won't display any information. So, 'pvdisplay' is not 100% check.

-Sri

Re: Physical Volume Existence

Michael Tully — Tue, 12 Oct 2004 22:19:32 GMT

There is one furthe one.

If the disk thinks it belongs to a volume group, it will tell you when you run this command.

pvcreate /dev/rdsk/c0t5d0

If it does then you should see it in /etc/lvmtab. If not, it should be okay to use. (re-use with pvcreate -f /dev/rdsk/c0t5d0)

Re: Physical Volume Existence

A. Clay Stephenson — Tue, 12 Oct 2004 22:26:15 GMT

Though is sounds insane and dangerous, pvcreate WITHOUT THE -f OPTION will fail, report an error, and exit if the disk already has LVM data structures on it. That is why the -f option is needed to override the default behavior. Man pvcreate for details.

Re: Physical Volume Existence

ddeblance — Thu, 14 Oct 2004 09:27:36 GMT

The -f in
#pvcreate -f /dev/rdsk/c0t5d0
forces it to create the LVM data structure.
#pvremove /dev/rdsk/c0t5d0
will remove the LVM data structure then it can be used by the files system.

Re: Physical Volume Existence

Prashant Zanwar_4 — Thu, 14 Oct 2004 10:04:31 GMT

# xd -j8200 -N16 -tu /dev/rdsk/c1t2d0
0000000 2000252410 965817345 2000252410 965817462
PV CPU-ID PV timestamp VG CPU-ID VG timestamp

The above information translates to:

â ¢ pvcreate and vgcreate was run on the sytem with systemID (uname â i) 2000252410

â ¢ pvcreate was run at timestamp 965817345 (seconds after Jan 1st 1970 0:00 UTC)

â ¢ vgcreate was run at timestamp 965817462 (117 seconds later)

Hope this helps.

Tha