Thursday, May 18, 2017

VM Performance Issue Troubleshooting

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.

Thursday, May 4, 2017

My VCAP6-DCV Deployment Exam Preparation

Last Friday, I finally sat on my VCAP6-DCV Deployment Exam after around 6 weeks of intensive preparation. The preparation itself is really exhausting. Need a lot of determination to keep it going with my study plan, and that includes sacrificing so many precious time with my loved ones during weekends and public holidays, which somehow there's so many public holiday in Indonesia in the last 6 weeks, and I don't know how many glass of coffees to ensure my eyes and brain active to receive all the information. My study plan is simple, VCAP6-DCV Deploy Exam has 26 objectives from 8 sections. So everyday, I try to cover all skills and abilities required for one objective. Though, a lot of time I missed the time target since the objective is so extensive to cover, or I was bustled with my work. I started my study with the blueprint sections which I think I strong, which are storage, network, availability and scalability, and performance, and then continue to the rest of blueprint sections.

Here is some sources which help me preparing the exam:
  • Official Exam Blueprint:
    • Officially only available online, pdf (like in VCAP5 days) no longer available
    • This blueprint will tell you all the official documents you need to be able to cover all skills and abilities required.
      • Read each skill and ability from each objective, find related basic theory on the manual, and then practice the steps required to implement that objective.
  • VCAP6-DCV Deployment Study Group:
    • Check this Google+ group for other test takers experience on preparing the exam.
  • Notable Study Guide (For Kyle Jenner, Mordi Shushan, and Ramy Mahmoud who dedicated their time to write these great study guides, your work are awesome! Much appreciated.)
  • VMware Hands-on Lab:
    • One of the key thing for this exam is to get your hands-on, so having access to a lab is really crucial. I have my personal lab, build a nested ESXi using VMware Fusion on two Macbook Pro, but I also leverage VMware Hands-on Lab extensively.
      • FYI my HOL account transcript records that I completed 25 labs during my exam preparation period. Some labs taken couple of times since the same lab can be used to cover some objectives.