There is a famous quote by Mark Twain “The reports of my death have been greatly exaggerated”, and despite claims made by All Flash disk array manufactures, this quote still holds true for 10 k SAS drives when comparing only cost per gigabyte. SSD drives have been and are still more costly per gigabyte than their spinning ancestors 10k SAS drives.
In the final instalment of this series, I’ll have a look at AFF setups that have about the same usable capacity, but are built out of different set of SSD drives. Both are using ADPv2 to maximize usable capacity.
This is also the point where things get little bit hairy.
In previous posts I was comparing apples to apples in hardware terms, the only difference was version of ADP used, solutions under comparison were equal in terms of total cost and performance. Since ADPv2 is more efficient, you can lower $/GB without altering total cost or performance, making AFF more cost effiecient, you get more bang for your buck.
This time I am comparing apples to oranges in hardware terms. Using different hardware components makes comparison more complex, it is not just about usable capacity, different hardware has also different performance characteristics and total cost. I am not going to touch performance aspect too much as it would overcomplicate the comparison.
In previous part 1 I wrote about NetApp AFF and ADP with smaller 400 GB SSD drives. This time I will concentrate on ADPv2 with larger SSD drives (3,8TB). As a reminder, with ADPv2 you can deploy 12 SSD disk setups while still having two data aggregates and two controllers serving data and thus getting better performance. So ADPv2 with 12 SSD drives is beneficial also with larger SSD drives.
NetApp has announced new version of their storage operating system, Ontap 9. One of the improved features is Advanced Drive Partition V2 (ADPv2).
With ADP you can slice SDDs or HDDs into two partitions, one for root aggregates and one for data aggregates. This means that you don’t have to reserve separate drives for root aggregates, instead you can use a small “slice” of disk for root aggregate and use remaining “slice” for data aggregates. By using ADP the overhead related to root aggregates is smaller and you will get more usable space for data.