I am trying to understand & design solutions for our customers on tiering support using Hitachi arrays.
As part of that, i would like to clarify few questions.
1. I am using external storage and created a HDT pool with tiers. I observed that none of the tiers showing driveType. Does Hitachi support tiering on external storage?
If it is supported, how to differentiate these tiers with different driveTypes?
2. If i define a Pool with three tiers and selected T3 policy, How the data placement happens?
3. Is it possible to assign a Lowest tier with diskType as SSD? or it is only meant for SATA drive? The reason for asking this question is: HiCommand CLI output doesn't specify a tier level i.e. high, medium and low. But there is a property "tierID" and it has values like 1,2,3. I am not sure whether i can correlate it with High,Medium and Low tier level. is my assumption correct?
Ex. There are few HDT Pools
1. Pool1 with tiers T1 (SSD),T2(SAS),T3(SATA).
2. Pool2 with tiers T1(SAS),T2(SATA) => Is this a valid pool with this configuration?
3. Pool3 with tiers T1(SSD), T2(SAS)
4. Pool4 with tiers T1(SAS), T2(SATA), T3 (SSD) => Is this a valid pool with this configuration?
Case 1:- If i choose T1/T2 as a policy, which is the best pool to select?
Case 2:- If i choose T1 as a policy, which is the best pool?
Case 3:- If i choose T2 as policy, which is the best pool?
Case 4:- If i choose All as policy, which is the best pool?
Thank you in advance.