We actually run a program that we call the HKC Analysis or more simple health check.
One part of this analysis is to check the SVC for typical performance risks.
I have collected some principal steps of this kind of analysis.
We call this part of the HKC analysis the "performance risk analysis".
If you are interested in this kind of analysis
or send a mail for more information to email@example.com
You need: (please see checklist for details)
- a BVQ Test license
- a Windows Server with 4GB Memory and 80BG disk capacity – this may be a VMware guest
- remote access to the BVQ server. We prefer Teamviewer (www.teamviewer.com) for this
- a service to install BVQ or you do it by yourself (ask here)
- some time to collect data – typically one week
- one of our engineers who will work together with you in a remote session and help you to interpret the BVQ results
It takes us only 20 seconds after the launch of BVQ to find the first answers for performance issues. The CPU usage of the SVC or Storwize is low with only 3% to 6%, the global R/W cache is on standard values but the global write cache fullness is much too high. A reason for this can be a slow storage backend or some SAN issues. The result of these peaks is normally what a server admin would describe as a slow SAN storage.
You have the knowledge and the tool – this allows you to go deep into the SVC and figure out what in detail happens in the cache partitions of the SVC. Each managed disk group is a cache partition and we have been alarmed by the global cache that there might be an issue. There is a quick way to find out which managed disk group is in trouble. From there we can go on into the analysis of the volumes.
It is only some mouse clicks away to see what is going on with the SVC Node ports. This analysis shows that the data rates on the ports are not an issue. Typical SAN errors are also not visible but the yellow line tells us about a SAN blockage. The SVC had to wait up to 40% of its working time for SAN Buffers. This might be a wrong parameter in the SAN switch or a slow draining device in the SAN.