Again, I was having a bit of day off from work – and didn’t really succeed. I think I might be a work-a-holic! I learned two things today. Firstly:

Hot-add might not be so hot after all:

In my book on vSphere4 I covered hot-add of CPU/RAM to the VM – knowing that that support for this featue was very much dependant on the Guest Operating System (aka Windows & Linux) – I set up a VM using the very latest version of Windows and the highest level – that is to say Windows 2008 64-bit Enterprise (OK, I didn’t have an .ISO of DataCenter Edition). I had pretty good experience.

But it has come to my attention via David Davis and Jason Boche (behind Jason’s name is link that takes you to his testing on hot-add) that hot-add might not be so hot after all. You see I just check the 2nd vCPU was just present in Task Manager. I forgot to check Device Manager and to see if cycles are actually scheduled on the new vCPU. According to Jason Boche – they are not – and in fact it seems like all the various flavours of Windows will require some kind of reboot.

Of the course, the really funny thing about hot-add is… wait for this… it’s not enabled by default AND you have to power down the VM to enable hot-add (Ahem…)… Anyway, I think there maybe a good reason why VMware chose not to enable hot-add as default. It’s incompatiable with VMware Fault Tolerence.

Anyway, not content to just take Jason’s word for it (not that I don’t trust/respect the guy) I want to give this hot-add business another try, and see what gives…

Installing EMC PowerPath for VMware:

For the last couple of days I’ve been playing with EMC PowerPath for VMware. As you might know ESX4 vStorage allows for storage vendors to add their own PSPs (Path-Selection-Plug-ins) and extend the functionality of the ESX beyond the standard PSP supplied by VMware (MRU, Fixed, Round-Robin). I was inspired by Chad Sakac recent blog post and video.

http://virtualgeek.typepad.com/virtual_geek/2009/07/howto-download-install-and-license-emc-powerpathve.html

The nice thing for someone like me – is that I was able to download the PowerPath software for free (the same couldn’t be said about the PDFs – hint-hint!) and Chad was kind of enough to allow me some NFRs that last a year. It does appear to be the case that theres some kind of “conflict” between storage views and PowerPath, Chad’s told me that VMware are working on patch to fix this issue – nothing major sounds like just a bit wonky xml.

Anyway, this is likely to end up in my book on vSphere4, but in case it doesn’t – I wrote a little PDF to explain how it is done. (or you could watch Chad’s videos)

This entry was posted on Wednesday, July 22nd, 2009 at 6:19 pm and is filed under ESX. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.