Yellow Bricks

by Duncan Epping

Outlook 2016 OSX requires activation?

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I ran in to this issue where Outlook 2016 for OSX said it required to be activated. Very annoying as I don’t have a 365 account and that is what it requires before you can use it. It seems that this problem was caused by the fact that I used an older version of the preview/beta in the past. It can simply be solved be taking the following steps:

  1. Open Terminal
  2. Type: defaults delete com.microsoft.Outlook
  3. Type: killall cfprefsd
  4. Exit the Terminal session and launch Outlook

This basically deletes all the current settings for Outlook and wipes the cache. Now you can enter your details again and it will all work as expected.

vSphere HA respecting VM-Host should rules?

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A long time ago I authored this white paper around stretched clusters. During out testing the one thing where we felt HA was lacking was the fact that it would not respect VM-Host should rules. So if you had these configured in a cluster and a host would fail then VMs could be restarted on ANY given host in the cluster. The first time that DRS would then run it would move the VMs back to where they belong according to the configured VM-Host should rules.

I guess one of the reasons for this was the fact that originally the affinity and anti-affinity rules were designed to be DRS rules. Over time I guess we realized that these are not DRS rules but rather Cluster rules. Based on the findings we did when authoring the white paper we filed a bunch of feature requests and one of them just made vSphere 6.0. As of vSphere 6.0 it is possible to have vSphere HA respecting VM-Host should rules through the use of an advanced setting called “das.respectVmHostSoftAffinityRules”.

When “das.respectVmHostSoftAffinityRules” is configured then vSphere HA will try to respect the rule when it can. So if there are any hosts in the cluster which belong to the same VM-Host group then HA will restart the respective VM on that host. Of course as this is a “should rule” HA has the ability to ignore the rule when needed. You can imagine that there could be a scenario where none of the hosts in the VM-Host should rule is available, in that case HA will restart the VM on any other host in the cluster. Useful? Yes, I think so!

Vote for the 2015 Top vBloggers now!

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Eric Siebert just opened up the voting for his “Top vBlog” again. Last year over 1400 people voted, and I am hoping that we will see an increase this year. I just went through the motion myself, and it only takes about 2 minutes. You select your 10 favourite blogs and put them in the right order, then you vote for the various categories. I had some new names in there, and many established names. Not revealing anything as I don’t want to influence anyone… this is YOUR vote, not mine.

Now before you start voting I would like to ask you to read Eric’s article around what some of your criteria should be when scoring up/down, and also make sure to check out Eric’s sponsor which helps out covering the costs and provided these prices, thanks Infinio!

Vote Now!

What happens at which vSphere memory state?

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I’ve received a bunch of questions from people around what happens at each vSphere memory state after writing the article around breaking up large pages and introducing a new memory state in vSphere 6.0. Note, that the below is about vSphere 6.0 only, the “Clear” memory state does not exist before  6.0. Also, note that there is an upper and lower boundary when transitioning between states, this means that you will not see actions triggered at the exact specified threshold, but slightly before or after passing that threshold.

I created a simple table that shows what happens when. Note that minFree itself not a fixed number but rather a sliding scale and the value will depend on the host memory configuration.

Memory state
 Threshold Actions performed
High 400% of minFree Break Large Pages when below Threshold (wait for next TPS run)
Clear 100% of minFree Break Large Pages and actively call TPS to collapse pages
Soft 64% of minFree TPS + Balloon
Hard 32% of minFree TPS + Compress + Swap
Low 16% of minFree Compress + Swap + Block

First of all, note that when you enter the “Hard” state the balloon driver stops and “Swap” and “Compress” take over. This is something I never really realized, but it is important to know as it means that when memory fills up fast you will see a short period of ballooning and then jump to compressing and swapping immediately. You may ask yourself what is this “block” thing. Well this is the worst situation you can find yourself in and it is the last resort, as my colleague Ishan described it:

The low state is similar to the hard state. In addition, to compressing and swapping memory pages, ESX may block certain VMs from allocating memory in this state. It aggressively reclaims memory from VMs, until ESX moves into the hard state.

I hope this makes it clear which action is triggered at which state, and also why the “Clear” state was introduced and the “High” state changed. It provides more time for the other actions to do what they need to do: free up memory to avoid blocking VMs from allocating new memory pages.

How do I get to the next level?

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Every week I get an email from someone asking if I can mentor them, if I can help them get to the next level, if I can help them become a VCDX, if I can explain to them what I did to progress my career. I figured I would write an article for those who wonder what I did, this is not a magic formula by any means, following the same path and putting in the same amount of effort is no guarantee for success. There is also that thing called “being at the right place, at the right time” and of course seeing opportunities, grabbing opportunities and taking risks.

First and foremost, I don’t wake up on a Monday morning and all of a sudden know how Virtual SAN or Virtual Volumes (as an example) work. It all comes down to putting in hours. If you can’t be bothered freeing up time, or have a too busy family schedule don’t even bother reading past this point. (Edit: family life is important, when I say “too busy” I refer to not being able to free up time as a result (or excuse for that matter.)) [Read more…] about How do I get to the next level?