pvremove does not exist on HP-UX 10.20

[Dieter S. Vener]

Hi Guys,

How the heck do you remove physical volumes on HP-UX 10.20? pvremove does not exist. I have some physical volumes that are allocated to old volume groups that no longer exist.

Thanks,

Weener

[Patrick Wallek · Accepted solution]

Are those VGs still in /etc/lvmtab? If so, and you are absolutely sure they are inactive, just vgexport those VGs to get rid of them.

You can then do a 'pvcreate -f' on the PVs so they can be used in other VGs.

[Dieter S. Vener]

Hi,

No, none of them are in /etc/lvmtab. I think some idiot that used to work here removed the volume groups using those pv's incorrectly.

Thanks for you help,

Weener

[Dieter S. Vener]

Patrick,

Thanks. I did not read your whole response. Does pvcreate -f ignore that the physical disk is already in use? When I run pvcreate /dev/rdsk/c2t0d6 alone with the -f option, I get a message saying the this device is already in use by another vg. I do know for certain that this disk is not already in use. I did a vgdisplay -v on all the volume groups that exist in lvmtab and none of them include this disk.

[Deoncia Grayson_1]

the -f option with pvcreate, forces the creation of the phyiscal volume

man pvcreate for more details

Warning: The -f option should only be used as a last resort to over write file system or volume manager information that cannot
properly be removed using the commands
designed for that purpose. When invoked with -f, the command does minimal verification, so care should be taken to assure that the disk is not already in use

[James R. Ferguson]

Hi Weener:

Even with the 'f'orce option of 'pvcreate' you are protected from removing a disk that is recorded in '/etc/lvmtab'.

Since, as noted, 'pvremove' doesn't exist on 10.20, you must resort to overwriting the LVM header yourself to destroy a disk.

# # mknod /dev/zero c 3 0x000003 #...on 10.20
# dd if=/dev/zero of=/dev/rdsk/cXtYdZ bs=64k count=10
# pvcreate -f /dev/rdsk/cXtYdZ

Regards!

...JRF...

[Bill Hassell]

pvcreate initializes the physical disk with basic LVM structures. The default pvcreate (without -f) will only write to an blank disk, that is, one that has never been used with LVM in the past. pvcreate -f will force the initialization but since this is completely destructive (especially to live data), it will see that the disk was used in the past for LVM and give you one last chance to verify that this disk can indeed be initialized.

The contents of lvmtab reflects active disks, so if you don't see your disk inj lvmtab, then it is not active. That doesn't mean that it hasn't been used in the past or has been temporarily deactivated by another sysadim. If you know that all required volume groups are active, then you should be OK with pvcreate -f.

[John E.Ophious]

Howdy Weener,

To be sure, you can also use sam to tell whether or not the disk is actually in use. The other gurus here have given enough good advice about pvcreate, so I wont go into that!!

Take care Weener,

John E. Ophious