I was just playing around with esxtop in vSphere 5.0 and spotted something that changed. I figured there must be more so I started digging. I didn’t dig too deep as there is a great VMworld session (VSP1999) on this topic by Krishna Raj Raja and I figured why re-invent the wheel. Anyway, here’s the things I noticed which will definitely [...]

Frank and I have discussed this topic multiple times and it was briefly mentioned in Frank’s excellent series about over-sizing virtual machines; Zero Pages, TPS and the impact of a boot-storm. Pre-vSphere 4.1 we have seen it all happen, a host fails and multiple VMs need to be restarted. Temporary contention exists as it could take up to 60 minutes [...]

During my flight from Boston back to the Netherlands I listened to the VMworld esxtop session “Troubleshooting using ESXTOP for Advanced Users, TA6720“. As always an excellent session with a lot of in-depth info. Most of it was already documented, however there were a couple of key points that I hadn’t documented yet. I just added those to my esxtop [...]

I have written multiple articles(1, 2, 3, 4) on this topic so hopefully by now everyone knows that Large Pages are not shared by TPS. However when there is contention the large pages will be broken up in small pages and those will be shared based on the outcome of the TPS algorythm. Something I have always wondered and discussed [...]

Today we had an interesting discussion on the VCDX mailing list. One thing I noticed a while back when I was randomly looking around in “esxtop” was a new field. The field is called ” RESVSTATS and can be enabled in all disk related displays(d, u,v). This will make troubleshooting storage related performance issues a bit easier as the SCSI [...]

I was just talking to Mr Alan Renouf and it appears that there are a couple of free slots left at the API/PowerCLI event that VMware has organized in coöperation with Alan on the 8th of October in London. If you are in London on the 8th October 2010 then you could be in for a treat, VMware are arranging [...]

Today I received a question around the difference between IOPS and CMDS/s. The reason for this was the high value of CMDS/s in “esxtop” which exceeded the expected amount of IOPS the disks could actually digest. I thought it would useful for everyone to know what the difference is: IOPS = Input/Output Operations Per Second Within esxtop this would be [...]