Quote:
Originally Posted by
jyoung
Can I change the allowed maximum phsical partitions while the system is running or do I have to perform a mksysb and make a change? What would be the steps to perform this. Thank you.
Short answer: yes, you can, but you should not.
You can double and even quadruple the number of physical partitions per physical volume, but only at the expense of halving (quartering) the number of physical volumes in the volume group. Normally a VG can hold up to 32 PVs with 1016 PPs each. You can introduce a so-called "factor" (of 2 or 4), which multiplies the PPs per PV but divides the number of PVs in the VG at the same time. The maximum storage capacity of the VG remains constant therefore. (See the man page for "chvg" for details about this factor.)
If you are starting to add disks (PVs) to the VG which have more PVs than allowed this is an indicator that you have chosen a bad value for the PP size compared to the storage demands of the VG. Probably the VG has been created long ago and the demands have outgrown the VGs capacity.
This is why you better back up the VG, recreate it with a more sensible PP size and then restore from the backup. You have a great opportunity to reorganise your storage layout and still stay flexible in every direction. In my experience introducing these VG factors is usually a last-ditch effort to avoid such a reorganisation and in the long run that causes more problems than are solved by it. Do yourself a favour and reorganise your storage now, when you *can* instead of some day very near in the future when you *must* do it.
I hope this helps.
bakunin