VMware

This is a description of a quick and dirty way to get SSL to work correctly in a VMware Horizon View installation in a lab environment. Do not do this in production!

When you use XenDesktop the only way it makes sense you may find that Citrix has not really put much effort into making that a smooth experience. Persistent is a Second-Grade Citizen XenDesktop is really designed to be used with pooled desktops - machines that are reset to a pristine state when the user logs off. Of course, stateless desktops are much better (and, importantly, cheaper) served from XenApp. This has been the topic of many a debate which I will not repeat here. But I will state that if you give a so-called knowledge worker a personal desktop, you better make sure that desktop is persistent.

Cleanly shutting down all virtual machines on a given set of hosts is not as trivial as it might seem - especially if you want to be able to restore the original state once the planned maintenance you are doing this for is completed.

There are situations when you have VMs on disk, but vCenter does not know about them - i.e. they are not in the inventory. While it is fairly easy to add a single machine to the inventory, doing so for dozens or hundreds or VMs is too tedious to do manually. This script automates the process.

When you buy a new HP server it comes with the BIOS setting HP Power Profile set to Balanced Power and Performance. That sounds good but is bad - at least for CPU performance in a VDI environment.

This kept us occupied quite a bit: after having worked with HP’s G7 line of servers for a long time, we ordered our first DL380 G8 for use with VDI. According to HP’s documentation the same custom image can (and must be) used when installing ESXi as with the G7. With that information, setting up the G8 sounded like an easy job: provision it via the existing automation mechanism and be done.

[Update on 29/06/2012: added tests 5 and 6 with RAID controller cache and Atlantis Ilio] When a 400 GB SSD comes nearly at the price of a small car, you expect a lot, performance-wise. At least I did when I got my hands on two drives from HP’s enterprise performance series. Read on to find out if that hefty price tag is justified.

The HotPlug functionality of VMware ESX(i) 4 and 5 has the negative side effect that it is easily possible to “eject” hardware devices from inside the virtual machine, completely removing the respective device from the VM configuration. This is especially bad if it happens to the network card, and others have already described how to prevent that from happening (e.g. here and here).

My last post on VMware VMotion urged several readers to protest, maybe because of its provocative title. What I did was to compare VMware clustering with Microsoft failover clustering. I got to the conclusion that both significantly add to the complexity of the environment. Interestingly, most commenters said, yes, Microsoft clustering is complex, but no, VMware clustering is not, yet failed to explain exactly why.