determine cluster resources

[khaliqamar]

Hi,

How i can determine my cluster is FULL. ( 80% or 90% host utilisation is enough ?  how many percent  I should consider  as borderline and any VMware recommendation ?)

As i know i have to count a slot sizes.

Is there any other way to determine my cluster is FULL.

Is there any freeware tool available for it which can count it ?

Thanks in advance

Regards

[rcporto]

On the summary tab of your cluster click on Advanced Runtime Info at vSphere HA section and you will see a lot of information about slots... and about your cluster utilization, first you need determine the failover requirements for your environment and then check if the utilization will support it.

[khaliqamar]

thank you rcporto,

in my cluster available slots 181 and my slot size 235 MB. so can i assume my available resources are 235*181 = 41 GB approximately.?

Is there any free tool available ?

[admin]

I would suggest you try the  RVTools - Home

Thanks,
Avinash

[khaliqamar]

Thanks Avinash,  I used RVtools before but I never see anything in RVtools that it can tell me the resources left in my cluster. It tells about the utilization.

Any idea about my previous comment about slots ?

[f10]

Hi,

To use the number of available slots while doing capacity planning is not quite accurate and misleading until and unless you have configured a minimum reservation of memory and cpu for the VMs. The slot size reported in the Advanced runtime information is calculated using default usage of 32MHz of CPU and ONLY 0MB + Overhead of memory of a VM which may not be the average/required VM cpu & memory consumption in your infrastructure. Also note that the number of slots corresponds to the number of VMs and for better understanding about how this is calculated I recommend that you go through the "Host Failures Cluster Tolerates Admission Control Policy" section of http://pubs.vmware.com/vsphere-55/topic/com.vmware.ICbase/PDF/vsphere-esxi-vcenter-server-55-availability-guide.pdf.

To get a practical number of available slots I would change the default CPU & Memory slot size using VMware KB: Manually configuring HA slot sizes in vSphere 5.x  however NOTE that this requires some calculation & understanding about the average CPU and memory usage in your infrastructure because these settings would impact admission control policy in HA. In general I always leave 20% headroom for spike and to tolerate host failure in cluster so you may configure default slot size accordingly.

-Arun

http://highoncloud.blogspot.in/

About VMware Virtualization on NetApp

[admin]

slots 181 and my slot size 235 MB. so can i assume my available resources are 235*181 = 41 GB approximately.?

>> yes

Ok. To Explain more about slot size.

You can compare it with the common parking lot, Now consider you have a space where you want to convert it into  parking lot,  you would make the partition based on the largest vehicle you would park or it can accommodate. Similarly the slot size is calculated based on a VM with the largest memory and CPU. consider you have 4 VM's - VM1 - 2Gb RAM ,VM2 - 4 Gb RAM, VM3 - 20 Gb RAM ,VM4 -2Gb RAM. Now consider your total memory available or left is 40 GB. Your available slots will be only 2. bcoz it considers the largest RAM.

and for the other you could check the vCenter operations manager. which would be the best for monitoriing resources.

Hope this clears.

Thanks,

Avinash