As in the AFF A200 announced contribution, I would like to you at this point the advanced disk partitioning v2 (ADPv2) by NetApp closer. Should be generally known that NetApp FAS / AFF systems 99% with RAID-DP (a kind of RAID 6) run. Double parity RAID-DP is available for RAID. I have two parity drives per RAID group, and ideally also a spare plate. Is certainly known that the respective controllers in one FAS / AFF disks "belong". These are assigned to the controllers via softwarebased ownership. I'm a little now a middle class customer for the FÁS 2650 or AFF A200 loose the next three to five years is enough, so I would even be surprised if 24 hard disks in the enclosure, only nine disks per controller are usable. According to NetApp best of practices of that time is but a dedicated root unit required. So an extra RAID Group on which only the root (operating system date) the NetApp lie. And again six plate waste. No one does so. Therefore the most customers have found easy to set the root of the NetApp data to your data RAID groups/units the way. It looked at the time so
: so six plate waste and no extra RAID group or Aggregate for the NetApp root volume. Now you changed her at NetApp: 'Mhh sucks Yes, if the customers do not observe our best practice and therefore expose the system to an unnecessary risk. What we need to do"
Said than done. And so it came to ADP v1:
Man has now from the individual hard drives small pieces "cut off", to create the root aggregate and the same RAID-DP to have protection, as I would use 3 dedicated discs for that. At a FAS 2552 with only internal plates I'm with ADPv1 on a usable capacity of 74% in an active/active configuration. in an active/passive configuration, I reach already 83% usable capacity. Data-to-overhead ratio of 18:6
But there is more…
The first SSDs were affordable but still expensive compared to normal HDDs. Now to explain you would need in a 2 node/controller configuration with 24 SSDs ever six disks for parity and spare would have probably the sales of SSD systems not just inspired. Given that the SSDs are still no bargain. Therefore, three partitions on a disk came 
with DataONTAP 9 that ADP v2 for SSDs have been here so instead of two partitions, set. As a result, I get a data-to-overhead ratio 21:3. Result: More net of the gross. Everyone of us wants 😉 The ADP works on following FAS / AFF systems with following configurations: prerequisite ONTAP 9.0
- FAS 25xx for SSDs and HDDs, FlashPool
- FAS 26xx for SSDs and HDDs, FlashPool
- AFF A200
- AFF A300
- AFF A700
- FAS 32xx FlashPool and SSDs
- FAS 62xx FlashPool and SSDs
- AFF/FAS 80xx FlashPool and SSDs
- FAS 90xx Flashpool and SSDs
- FAS 82xx Flashpool and SSDs
Note, however, that existing systems do not "just" in operation on ADP can be converted. Even if you updated on Data ONTAP 9, you must reinitialize the system and have previously secured all data to another system! I hope you got a good insight into the ADP v1 and v2 ADP. If you have questions, just use the comment function. Greeting DerSchmitz