jklick's Accepted Solutions

2. Although ESXI 4.1 allows you to limit the 1 - 2.5GHz vCPU to 4000GHz, it does not make any sense to put this limit in.     The limit would be only useful where you are tryiing to allow for f... See more...
2. Although ESXI 4.1 allows you to limit the 1 - 2.5GHz vCPU to 4000GHz, it does not make any sense to put this limit in.     The limit would be only useful where you are tryiing to allow for fractional vCPUs - like <1 or 1.5. ?? The first part is correct. Much like memory limits, they only affect the VM if the limit is set lower than the allocation. Otherwise, the allocation already "limits" the VM. I don't think the second part would work like that. Either a VM is using a core or it is not. For example, if you allocated two vCPUs and limited it to 3 GHz, it would still use 2 vCPUs regularly. However, if it attempted to use more than 3 GHz, then it would get limited in its consumption. Because of both these facts, there's only two potential use cases for CPU limits that I can think up at the moment: Testing purposes. If you want to see the impact of CPU contention (CPU ready) on a virtual machine, CPU limits are great for that. If you have a VM that starts consuming all its allocated CPU and starts to impact the performance of other virtual machines. CPU limits can be created and removed instantly, without having to power off the VM.
I don't have any additional KB articles than the ones already listed. However, I've seen this issue several times before and as a preventative measure I'd check the statistics levels in your vCen... See more...
I don't have any additional KB articles than the ones already listed. However, I've seen this issue several times before and as a preventative measure I'd check the statistics levels in your vCenter server settings for anything above 2, particularly since you inherited the environment. When statistics level 3 and 4 are used for extended periods of time, it has a tendency to cause this problem due to the extreme amount of metrics that need to get rolled up regularly.
mittim12 wrote: I've seen ballooning start happening if you have a VM with 2 GB of memory assigned and then you put a limit on it of 1 GB.   The ESX host should attempt to balloon out the 1GB... See more...
mittim12 wrote: I've seen ballooning start happening if you have a VM with 2 GB of memory assigned and then you put a limit on it of 1 GB.   The ESX host should attempt to balloon out the 1GB extra that was assigned to the VM.  That works under a lot of circumstances, but if the VM is not yet consuming more than the value you set for a limit (i.e. < than 1 GB), ballooning will not appear.  For guaranteed results, check the performance charts to see what level of memory consumed the VM has.  Then, go into the edit settings for the VM and set a memory limit for a value below the memory consumed level.  The lower the limit, the more dramatic the results.  In fact, after you set the limit, go over to your memory performance chart and watch the ballooning rise. Out of curiosity, what sort of testing are you doing? ---------- Jonathan Klick VKernel Systems Engineer