Always Remove Unnecessary Hardware on a VM after Doing P2V
One day, a customer of mine called me asking for advise for an application that his team has just P2V but was having performance issue. As usual, my response was to understand the issue and the application itself, came up with some suggestions, including asked them to raise a support request (SR) to VMware Support. Couple of days passed by, but no resolution on the issue. So I decide to visit the customer to see whether I can help. This blog documents the process I took which ended on resolving the issue, and points out one important step post P2V which tends to be missed out.
What's the issue? On what ground the user said the application is slow?
This is the first thing I try to understand if facing a performance issue. Can the user really quantify the slowness? Or is it just based on feeling? For this case, the performance issue was quite clear. They showed me that running one process took about 10 seconds in P2V app, where in physical normally only 3 seconds. Ok, now I know what to expect. My goal was to get that 3 seconds back.
What's the application? How's the architecture? How user access it?
Next is to know what application is that. We might want to cross-check whether any documented best practice available for that application. One place to check is at Virtualizing Business Critical Applications page on VMware website, or just Google with keyword "application name on VMware best practices". If one exists, you can use it to later check whether the VM/application already configured according to the best practices.