add a hdiskpower in a vg

good morning

I want to add a new emc disk in a vg (it is not a big volume group)
but when i do it, i have the message:

0516-1162 /usr/sbin/extendvg: Warning, The Physical Partition Size of 64 requires the creation of 3200 partitions for hdiskpower48. The limitation for volume vg01 is 3048 physical partitions per physical volume. Use chvg command with -t option to attempt to change the maximum Physical Partitions per Physical volume for this volume group.
0516-792 /usr/sbin/extendvg: Unable to extend volume group.
Set Characteristics of a Volume Group

if i try to change the volume group to a big or a scalable, it is refused.
i think too that it is not chvg -t but chvg -P to attempt to change the maximum Physical Partitions per Physical volume. But chvg -t or -P are too refused :frowning:

thank you for your help

what kind of error messages are you getting with the chvg command?

the VG is varied off when you try, right?

try

chvg -t 3

This will change the number of PP/PV by a factor of 3.

See the following.
http://publibn.boulder.ibm.com/doc\_link/en\_US/a\_doc_lib/cmds/aixcmds1/chvg.htm

thank you
when i do a chvg -t 3, it says to me that the vg is not scale
if i try to do scale, it says that the vg must be varyoff.....and of course, i can't do a varyoff, it's an important server in production.... !!!

did you try chvg -t 4?

The LVM imposes several limits, all of which have to be considered. On a PV level the most important ones are:

not more than 1016 PPs per PV
not more than 32 PVs per VG

You can change that behaviour by converting a VG to "big", which means halving (quartering, ...) the number of possible PVs per VG whilst increasing the number of PPs per PV accordingly. This usually doesn't make sense for a VG factor beyond 2.

Better in this case is to back up and recreate the VG with more sensible values. It makes sense in most cases to set the PP size to 128MB or even 256 MB, which allows for single PVs as big as 130 (260) GB. It may be more effort *once* to do this but in the long run it pays off not to have to twiddle with the different factors in the VG - too many restraints to be obeyed in the long run.

bakunin