Adaptive & Dynamics Optimization
This is when of the great 3PAR StoreServ features, allowing ‘regions’ of data to be moved between different storage tiers. 3PAR OS includes the data movement engine, however it has to be unlocked either using Dynamic or Adaptive Optimization.
Adaptive Optimization this is the automated movement of ‘regions’ of data based on policies. The really cool thing is you can have different RAID types on the same physical disks e.g. RAID 5 and RAID 6 on the same 10K SAS Disks. The policies can be used to sample performance during the working day and then then data movement can be scheduled out of hours.
Dynamic Optimization is the manual movement of complete LUN. Using DO, we have the ability to change the class of service seamlessley you want to move from RAID 6 on 10K SAS to RAID 5 on 15K SAS not a problem. This means we can move an application from a higher class of service to a lower class of service or vice versa on the fly. Sheldon Smith a HP Technology Consultant has confirmed that the limit has been removed when tuning a Virtual Volume using Dynamic Optimization,
Now that Adaptive Optimization is On Node, it brings with it a few performance enhancements.
We do have some Adaptive Optimization recommendations for valid configurations, these are:
- 2 Tiers with SAS 15K/10K and NL
- 2 Tiers with SSD and SAS15K/10K
- 3 Tiers with SSD, SAS 15K/10K and NL
So how do I size a 3PAR StoreServ to use Adaptive Optimization? Well the following is the recommended practice:
SSD – 2 – 3% of capacity and 50% of the performance requirement
SAS – 35 – 40% of the capacity and 50% of the performance requirement
NL – Rest of the capacity (don’t include performance figures)
Adaptive Optimization Configuration
Pretty straight forward, you need to have at least three linked Common Provisioning Groups with at least two tiers of storage for AO to work.
I have mentioned before that 3PAR like to use 0’s. They apply this logic to the tiering.
Tier 0 – Low Capacity & High IOPS normally SSD
Tier 1 – Mid Capacitity & Medium IOPS normally SAS
Tier 2 – High Capacity & Low IOPS normally NL
We have a choice of three modes, which are:
Performance—Be more aggressive moving data to faster (higher) tiers
Cost—Be more aggressive moving data to slower (lower) tiers
Balanced—Between performance and cost
You can see below that changing the settings is fairly straight forward, we have our System Name, Domain (if applicable) and then our Tiers and how often we want AO to run.
Adaptive Optimization Sampling
The the sampling begins this is performed at a 5 minute interval and captures the following details:
- Sample time
- Read IOPS, Write IOPS and Total IOPS
- Read KB/Sec, Write KB/Sec and Total KB/Sec
- Read service time, Write service time and Total service time
- Read KB size, Write KB size and Total KB size
- Queue Length
Note, that System Reporter has to run for at least three hours before any Adaptive Optimization can be scheduled.
Adaptive Optimization Troubleshooting
A common issue is the sampling period hasn’t had enough time to complete, the resolution to this is to err leave it a bit longer.
Another issue is that when you go to start Adaptive Optimization you receive the error ‘no matching VV found’ this is resolved by creating an .srdata volume by using the ootb command.