Can't change the volume group type to Big or SVG because not enough free physical partitions exist for the expansion of the volume group descriptor area.

First run the command "lspv – M hdiskX” to list logical partitions occupying the first physical partitions on the physical volume:

PVname:PPnum [LVname: LPnum [:Copynum] [PPstate]]

For hdisk1 and hdisk2 we will move the first 2 PPs to hdisk3 using the migratelp command :-

migratelp LVname/LPartnumber[ /Copynumber ] DestPV[/PPartNumber]

for hdisk1 :-

# migratelp testlv/21 hdisk3

For hdisk2 :-

# migratelp testlv/70 hdisk3

Then check again :-

# lsvg -p testvg
testvg:
PV_NAME           PV STATE          TOTAL PPs   FREE PPs    FREE DISTRIBUTION
hdisk1            active            49          2           02..00..00..00..00
hdisk2            active            49          2           02..00..00..00..00
hdisk3            active            99          43          07..00..00..16..20

Option 2 :-  If all disks in the volume group have zero free PPs, you may be able to shrink a filesystem to free up the required number of PPs.  PPs will not be freed equally on all disks, so you will likely need to use option 1 after shrinking to create free PPs on each disk.

Try to Shrink the Filesystem by the number of PPs that you require using the command :-

# chfs -a size=-“PP size” /mountpoint 

Option 3 :-  If you have not reached the limit of maximum PPs per PV, and the disks are RAID devices, you can dynamically expand the disks on on the storage array.  Then on AIX run "chvg -g vgname" to detect the added PPs on each PV.

Option 4 :-  if the above options are not viable, the last option is to backup the volume group contents and restore it to a big or scalable VG.