This was probably one of the coolest sessions of VMworld. Irfan Ahmad was the host of this session and some of you might know him from Project PARDA. The PARDA whitepaper describes the algorithm being used and how the customer could benefit from this in terms of performance. As Irfan stated this is still in a research phase. Although the results are above expectations it’s still uncertain if this will be included in a future release and if it does when this will be. There are a couple of key take aways that I want to share:
- Congestion management on a per datastore level -> limits on IOPS and set shares per VM
- Check the proportional allocation of the VMs to be able to identify bottlenecks.
- With I/O DRS throughput for tier 1 VMs will increase when demanded (More IOPS, lower latency) of course based on the limits / shares specified.
- CPU overhead is limitied -> my take: with the new hardware of today I wouldn’t worry about an overhead of a couple percent.
- “If it’s not broken, don’t fix it” -> if the latency is low for all workloads on a specific datastore do not take action, only above a certain threshold!
- I/O DRS does not take SAN congestion in account, but SAN is less likely to be the bottleneck
- Researching the use of Storage VMotion move around VMDKs when there’s congestion on the array level
- Interacting with queue depth throttling
- Dealing with end-points and would co-exist with Powerpath
That’s it for now… I just wanted to make a point. There’s a lot of cool stuff coming up. Don’t be fooled by the lack of announcements(according to some people, although I personally disagree) during the keynotes. Start watching the sessions, there’s a lot of knowledge to be gained!