can't vgcreate: IO error on Physical Volume device

[Natasha L.]

Hello all,

I am an HPUX newbie setting up a new 11i box. It shipped with 2 hard disks, but:
- there is only one vg containing one pv
- there is only 24 MB in /home

What I would like to do is create a new vg01, assign the second disk to it, create a huge lvol on it, and then relocate /home to that lvol by editing /etc/fstab. That way /home is sitting on its own disk with gigs and gigs to play with.

I set about doing this. First I checked that the box sees two hard disks:
#ioscan -fn | grep disk
disk 0 0/0/1/1.15.0 sdisk CLAIMED DEVICE HP 36.4GST336753LC
disk 1 0/0/2/1.15.0 sdisk CLAIMED DEVICE HP 36.4GST336753LC

Then I checked for pvs and saw two:
# ls /dev/dsk
c1t15d0 c3t15d0

When I checked them out:
bash-2.05b# pvdisplay /dev/dsk/c1t15d0
--- Physical volumes ---
PV Name /dev/dsk/c1t15d0
VG Name /dev/vg00...

# pvdisplay /dev/dsk/c3t15d0
pvdisplay: Couldn't find the volume group to which physical volume "/dev/dsk/c3t15d0" belongs.

OK. Looks like pv c3t15d0 is our second disk that hasn't been assigned to a vg yet. So I went ahead and did the vg setup:
# mkdir /dev/vg01
# mknod /dev/vg01/group c 64 0x010000

The next step didn't work:
# vgcreate /dev/vg01 /dev/dsk/c3t15d0
vgcreate: IO error on Physical Volume device /dev/dsk/c3t15d0:

So my questions are:
1) How can I verify that /dev/dsk/c3t15d0 really is my second disk drive? Is there a command that basically lists pvs mapped to the ioscan info for their disks?

2) If /dev/dsk/c3t15d0 is not my second disk... what is it? can I get rid of it? if so, how?

3) If /dev/dsk/c3t15d0 is not my second disk, I know I need to use pvcreate /dev/dsk/cXtXdX
to associate the second disk with a pv. Can I plug whatever I want into the X's?

Any advice much appreciated.

Sincerely,
Natasha

[Paula J Frazer-Campbell · Accepted solution]

HI

Use SAM it is quick and easy.

Paula

[melvyn burnard]

I believe you had all your steps right except for the missing one which was to do a pvcreate /dev/rdsk/c3t15d0 before doing the vgcreate
This failed as htere were no LVM headers written to the pv

[Pete Randall]

Natasha,

First off, when you do your ioscan, the second line should also show you the device file associated with each disk. Secondly, because your second disk /dev/dsk/c3t15d0 has not been used for LVM space yet, you need to first pvcreate it: "pvcreate /dev/rdsk/c3t15d0". The rest of your steps are fine. The EXAMPLES section of man vgcreate show a good example of the steps to follow. Or use Paula's suggestion of doing the process via SAM.

One other concern: "bash-2.05b# pvdisplay /dev/dsk/c1t15d0" Is this indicating that you've changed root's shell to bash? If so, change it back. You're going to end up with an unbootable system.


Pete

[Natasha L.]

Hi all, thanks for the replies!

I am trying SAM now.

I did try a pvcreate but got:

# pvcreate /dev/dsk/c3t15d0
pvcreate: "/dev/dsk/c3t15d0": not a character device.

Googled this with no results.

Thanks,
Natasha

[Pete Randall]

Natasha,

The pvcreate command needs the raw device:

pvcreate /dev/rdsk/c3t15d0

(note the rdsk as opposed to dsk)


Pete

[James R. Ferguson]

Hi:

You need the raw device file. Instead of"

# pvcreate /dev/dsk/c3t15d0

...do:

# pvcreate /dev/rdsk/c3t15d0

Regards!

...JRF...

[Elena Leontieva]

You should do:

pvcreate /dev/rdsk/c3t15d0

[melvyn burnard]

As per my first reponse, you use /dev/rdsk/c3t15d0
Note the r in front of the dsk, to give you the raw or charatcter device, and not just dsk, to give the block or "cooked" device

[Natasha L.]

Hi everybody,

Thanks so much for the swift replies! Pvcreate with rdsk did the trick. And next time I will use SAM. 8)

Sincerely,
Natasha