virtual machine performance – add cpu ready alarm

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%*. […]

Performance 'snorkel dives' and other stuff

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… […]

virtual machine cpu limits – monitoring limitations

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 […]

virtual machine cpu limit considerations

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 […]