Problem Adding Phisical Disks to a Volume Group.

[NIGEL WHITE_2]

Hello,

I have a volume Group called vg19. It has a PV sized at 5G. When I try to add another PV of 15G to extend the size of the Volume Group, I get the following error:

vgextend: Warning: Max_PE_per_PV for the volume group (1279) too small for this PV (3839).
Using only 1279 PEs from this physical volume.

Now in LINUX, I have Volume Groups with multiple LUN sizes, so why is HP-UX forcing my bigger luns to 5G???

What do I do to get the full size of the disk used without rebuilding my VolGroup??

Regards
Nigel

[Rita C Workman]

...Put it in a vg that is set up for that size.

Rita

[whiteknight]

Hi Nigel,

Yes, possible

vgmodify is a new command from HP to modify the Max PE per PV and it 's official introduced by a patch for HPUX 11iv2 (11.23). However, the vgmodify becomes a built-in function in 11iv3 (11.31).

For 11.23, the current patch (or latest) for vgmodify is:
[formatted]
PHCO_35524 s700_800 11.23 LVM commands patch


Hope this help.
WK

please assign points

[A. Clay Stephenson]

When a VG is created the maximum number of Physical Extents per Physical Volume is set to accomodate the largest PV listed in the command UNLESS max_pe's is explicitly set when vgcreate command is executed. Max_pe's cannot be increased beyond that unless you are running a version of HP-UX (11.23 & up) on which the vgmodify command is available.

You can add larger disks to an existing VG but only a portion of the disk will be usable --- unless you run vgmodify.

[NIGEL WHITE_2]

Thanks guys.

I'm running 11.11, so I'm in a bit of bother.lol

So not to waste any space, how do I remove the 15G disk from the Volume group? I've been told you cant just remove the disk with vgreduce, you need to so some other stuff too??? EXMAMPLES PLEASE...

If I can remove the disk from the group, ill resize it on the EVA and then re-present it, then add it back with 2 more 5g luns to acheive my goal.

What a nightmare.lol

Thanks.

Nigel

[James R. Ferguson]

Hi Nigel:

You can simply run:

# vgreduce /dev/vg19 /dev/dsk/cXtYdZ

...without doing anything else as long as all you did before was a 'vgextend'. If you also added or extended logical volumes onto this device, you must remove those, first.

Regards!

...JRF...

[Tingli]

I think you need to defrag the disk first. It is:

fsadm -F vxfs -de /myfs

Then you can reduce the file system.

[A. Clay Stephenson]

No, no fsadm command is needed. If all you ran was vgextend and did not follow that up with an lvextend command then just do a vgreduce and you are ready to go. Depending upon how the new smaller LUN's are carved up (or if a LUN was used before0, you may have to use the -f (force) option when you run pvcreate this time. Try it w/o first and if you get a warning about already belonging to a VG then assert -f but iff you have carefully checked that that LUN is not in use (possibly on another host).

[Luk Vandenbussche]

When you create a new volumegroup without any specific option the parameters of the volumegroup are dependent of the disksize

check vgdisplay -v vg19

=> Max PE per PV : x
=> PE Size (MBytes) : y

The maximum size of a disk / lun = x * y

You have also a paramater Max PV. This is the maximum of Luns you can have in your VG

Use vgremove to remove the 15 GB Lun

vgremove vg19 /dev/dsk/cxtydz

[Luk Vandenbussche]

PS : Don't forget to submit point to the answers on your questions

[NIGEL WHITE_2]

Thanks guys, how do i assign points to you chaps?

[Dennis Handly]

See the forum overview:
http://forums1.itrc.hp.com/service/forums/helptips.do?#overview
http://forums1.itrc.hp.com/service/forums/helptips.do?#33