As part of my preparation for the VCAP5-DCA I needed to sharpen up a bit in some of the cmdline areas that I wasn’t overly familiar with. Listed in the blueprint for the exam are areas such as creating storage claimrules with esxcli, using vscsiStats or creating ESXi Image builds.
Some of these cmdline tools are more discoverable than others and while you aren’t required to memorise how they all work since you have the documentation available in the exam, you won’t really have time to look it up. I also found the quality of the built-in help for the various commands to vary quite significantly, so relying on that route could be problematic too. For instance if you need to add a storage claimrule the help at that point has a bunch of handy examples which you can copy and amend where necessary, but others aren’t so good. In the example below we need to mask a storage path and there is a very similar example in the help.
esxcli storage core claimrule add -r 500 -t location -A vmhba35 -C 0 -T 1 -L 0 -P MASK_PATH
The best thing to do is get as much hands on experience with each tool as possible. However, I still found it useful to note down examples of how to use each one as I worked through the various study guides and videos, so that when re-visiting a topic as an exam refresher I could quickly get my brain in gear for what was needed.
Similar to how I used to memorise the Configuration Maximums for the early VCP exams, I pinned each sheet up around my study area after working it through in the lab. Then over the next few days I would test myself on each topic and see how quickly I could remember the commands to run through to say add a claimrule and make it active, or create a custom esxtop config.
So I’ve zipped my cmdline quick summary sheets up and attached them to the bottom of this post in case you might find the same approach useful. There are summaries for:
|ESXi Image Builder|
|Esxtop Export and Replay|
|Mark As SSD|
The point I need to stress is you can’t memorise the commands for every possible scenario, but being able to quickly remember which ones to use and the syntax for how they work can be helpful in the exam when time is of the essence.
“Now how do you mark that disk as an SSD again……..?”