Thank you for your reply.
I know that the aggr snap reserve can change up if you have SyncMirror and it needs more space for its snapshots. It is then reduced back to set value if the need for extra space is no more. So there must be some mechanism that can adjust the value. I was searching in netapp doc and google but had no luck finding any description of the mechanism.
They do not use SyncMirror. They only use SnapMirror. Just to clarify.
I don't think that it was just in memory. How could it be set only in memory? All changes are immediate and permanent. I don't know about some "save" command that must be run to preserve the configuration...Or do I miss something?
Thank you very much