Yellow Bricks

by Duncan Epping

ESX

vmktree 0.3.0 out of beta!

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If we look at the VMTN community today there are a whole lot of people sharing powershell scripts, perl and even .net programs. Back in the days of ESX 2.x there wasn’t such a huge community, but there was one tool that everyone knew about and probably everyone tested and used at one point, vmktree!

Lars Trøen is man behind vmktree and he just released 0.3.0. For those of you who don’t know what vmktree is:

vmktree is a free web tool that shows you the graphs of resource usage of VMware ESX Server, VMware Server (on Linux), GSX Server (on Linux) and a few other data center devices (ilo/ilo2/rsa2/ds4000).

On VMware Server (and GSX) and ESX 3.x vmktree provides it’s own agent that collects system statistics and does not depend on vmkusage like it does on ESX 2.x. On ESX 3.x there is no agent installed on the ESX server itself as all values are polled from the machine vmktree is installed on.

vmktree is compatible with ESX and ESXi and needs to be installed outside of the Service Console, in contrary to previous versions. Lars created a great howto, which includes a CentOS jeos VM. I hope Lars can find some extra time and get that live esxtop back in again!

Increasing the queue depth?

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One of the most promising blogs of this moment is definitely Frank Denneman‘s blog. Frank is a freelance consultant with a focus on virtualization and storage. His latest addition “Increasing the queue depth” is an excellent article and really shows that Frank knows what he’s talking about!

When it comes to IO performance in the virtual infrastructure one of the most recommended “tweaks” is changing the Queue Depth (QD). But most forget that the QD parameter is just a small part of the IO path.

The IO path is made up of layers of hardware and software components, many of which can have a huge impact on the IO performance. The best results are achieved when the whole system is analysed and not just the ESX host alone.

I’m not going to copy and paste his entire article of course. Head over to his website and start reading. I can also recommend these articles: SRM and HP Continous Access DR Group Design and HP CA and the use of lun load balancing scripts. Don’t forget to bookmark the site or add it to your rss reader!

VMware VI3 Implementation and Administration by Eric Siebert

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vI just finished reading a brand new book titled “VMware VI3 Implementation and Administration” by Eric Siebert. I was pleasantly surprised by the in depth information that the book contains. The book is based on ESX(i) /vCenter 3.5 U3 and discusses every aspect of implementing and administering your virtual environment including troubleshooting, installation, backup and monitoring.  What ATDG is for 3.0.x this book will be for 3.5 in my opinion!

Eric’s writing style made the book an easy read and the enormous amount of examples, tips and hints make this book a must have for the toolkit of every VI Admin! In other words, pre-order it now!

Virtualized MMU and Transparent page sharing

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I’ve been doing Citrix XenApp performance tests over the last couple of days. Our goal was simple: as many user sessions on a single ESX host as possible, not taking per VM cost in account. Reading the Project VRC performance tests we decided to give both 1 vCPU VM’s and 2 vCPU VM’s a try. Because the customer was using brand new Dell hardware with AMD processors we also wanted to test with “virtualized MMU” set to forced. For a 32Bit Windows OS this setting needs to be set to force other wise it will not be utilized. (Alan Renouf was so kind to write a couple of lines of Powershell that enabled this feature for a specific VM, Cluster or just every single VM you have. Thanks Alan!)

We wanted to make sure that the user experience wasn’t degraded and that ESX would still be able to schedule tasks within a reasonable %RDY Time, < 20% per VM. Combine the 1vCPU, 2vCPU with and without virtualized MMU and you’ve got 4 test situations. Like I said our goal was to get as much user sessions on a box as possible. Now we didn’t conduct a real objective well prepared performance test so I’m not going to elaborate on the results in depth, in this situation 1vCPU with virtualized MMU and scale out of VMs resulted in the most user sessions per ESX host. [Read more…] about Virtualized MMU and Transparent page sharing

HA and ESX 3.0.x log file flooding

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VMware just released a new KB article. The article is on VMware HA and the log files it can possibly generate when restarting of a VM occurs.

The article contains an extensive description of the sympoms but the most important one is this one:

For any virtual machine that VMware HA is wrongly trying to start, it also generates thousands or tens of thousands of vmware-x.log files (one created every few minutes). Contents of each log file shows the virtual machine starting up then failing to start. Despite these logs, the virtual machines are actually pingable and running, and vm-support -x shows them as available running virtual machines on the host.

The resolution for the problem is the following:

  1. Stop and start HA on the cluster. (This stops the flooding)
  2. # find . -name ‘-*.log’ | xargs rm
    This commands removes all log files. Make sure you run this from /vmfs/volumes!