On a HUS system in Auto DP Optimize i can set a "Threshold" value for a DP-Vol.
What is it good for? When the DP-Vol grows of this amount?
when the Auto DP Optimization mode is set, the unused capacity is monitored everyday and DP Optimization starts when the unused capacity equals or exceeds the Auto DP Optimization threshold value.
Hence, if you have 'n' number of DP Vols in DP Pools, you dont need to keep a manual tab on each of them. the optimization takes care of it, unless you want it manually.
Hope this helps.
It basically runs DP optimization, re-striping (NOT a ZPR) when the unused capacity within the allocated DP-VOL reaches the threshold (or the pool does). Honestly, we don't use it, in most environments we've found the trigger is rarely fired with a high frequency and most users will tend to buy more disks and then run a optimisation manually before the small gains made by this function are realized.
So you say that it's basically for an automatic rebalancing of chunks between Raidgroups of a DP Pool (what the array is doing somehow anyway when allocating new chunks), but it's better to use Manual Optimization (which is also only useful when adding disks).
Auto DP optimization mode is a new option that when selected, automatically monitors unused capacity daily for each DP volume in a Dynamic Provisioning pool and each tier in a DP volume assigned to a Dynamic Tiering pool, maximizing efficiency. Refer to the “Auto DP optimization mode” section of the newly published Hitachi Unified Storage Provisioning Configuration Guide (MK-91DF8277-04) for details.
I couldn't find the guide though to see what config modifications it can have. May be you can find
When you say "unused capacity", it means that the Operating System must be able to and have released the blocks before somehow, like VMware with "vmkfstools -y" ?
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