HPE Storage Users Group

I am new to HP 3PAr and got couple of questions as below regarding HP 3PAR Adaptive Optimization. Can someone put some lights on it?

1. Does it matter if the FC disk space fills up? Or does AO just make do with what it’s got, even if FC disk space is full?
2. Is it possible to leave AO switched on but select certain Vols which are in FC disk now so that they are kept on NL disk only? Ie. hard set them so they never get moved to the FC disk?
3.If it is possible, how could you do it and what impacts or considerations if any?

1. With AO your FC tier must always have free space left. No matter if NL or SSD are full. Your VVs involved in AO policies must be provisioned by FC tier.

2. You can mix AO CPGs and non AO CPGs. There you must pay attention to free space in any of your tiers...

3. Create CPGs not involved in AO policy then create VVs or use DO (tunevv) to move VVs to this CPG. You must be carefull how you set warning limits on AO CPGs to keep enough free space on tier which provisioned non AO VVs.

1 - As long as there is NL drive space avialable the array will never deny a write if FC is filled up if FC is the user CPG. This is less than ideal situation, but the array will always write to a lower tier if the top tier is full.

2 - you can do this, but those disks need to be a in a CPG you create that is not part of an AO config. We do this all the time. We have some large low usage file servers that we do not want occupying FC space so we have a special CPG that is NL drives that is not part of an AO config, thus these vols stay in NL.

3 - As a note you need to be careful when the same class of disk is used by multiple CPGs that may participate in AP. AO has no way of knowing that a given class of disk in in different AO configs or even outside AO, thus when AO runs unless you have Growth Warnings set AO assumes it has all the disk of a given class assigned to that CPG at its disposal to use. It can get tricky and scary on systems with low available space, we have been there and it is not fun.