Category Archives: Miscellaneous

Application issues, undersizing a virtual machine, or applying a restrictive cpu limit can all result in cpu ready CPU Ready is the primary indicator of a cpu performance issue. Although it’s possible to create a cpu-ready alarm, every VMware admin needs to be able to recognize what the values mean.   How much cpu ready is ok It is […]

High cpu ready values are probably the single most recognised sign that a virtual machine is having problems, whether due to application issues, or cpu undersizing, the vSphere admin should know about it. Setting an alarm for this is so simple and flushes out the bad boys. The suggested settings are from VMware, 20% and 40%*. […]

virtual machine cpu limit considerations Several years ago some of VMware’s most respected technical experts made recommendations against using virtual machine cpu limits. So why does this feature exist, is it a viable method to apply costing controls in the same way telephone companies put MB limits on internet usage, and what exactly are the possible impacts… […]

In the previous post I wrote about virtual machine cpu limits and finished off by mentioning that limits are not exposed to the guest OS. That cpu limits can cause additional overhead, that your vm is hyperventilating because it cannot get enough cpu per cycle is a worry, but when it happens how do you […]

Several years ago some of VMware’s most respected technical experts made recommendations against using virtual machine cpu limits. yellow-bricks limiting-your-vcpu More recently VMware stated “Resource limits on a virtual machine… form an artificial boundary… you need to take the possible impact into consideration before applying limits to either memory or CPU.” Impact of virtual machine CPU resource […]

Diagrams of Path Failover for active/active, active/passive and ALUA storage arrays. Active/Active   Active/Passive   ALUA  (Take note of optimized paths)  

VCAP 5.5 DCA If you are preparing to take the VCAP DCA, you need to spend hours in lab practice. Set up your test lab like the exam lab, and you will gain time and confidence. The following diagram was more or less valid for the 5,5 exam in early 2015. VCAP-DCA Lab   VCAP […]