VMware Cloud Community
tdubb123
Expert
Expert

very high ready and wait times

am i seeing a cpu bottleneck here?

Screen Shot 2017-02-15 at 8.16.48 AM.png

0 Kudos
11 Replies
MattiasN81
Hot Shot
Hot Shot

You need to provide a little more info

How many CPUs/Cores on the host?

is these values realtime, past day, past month?

VMware Certified Professional 6 - DCV VMware VTSP Software Defined Storage Dell Blade Server Solutions - EMEA Certified Dell PowerEdge Server Solutions - EMEA Certfied Dell Certified Storage Deployment Professional Dell EMC Proven Professional If you found my answers useful please consider marking them as Helpful or Correct
0 Kudos
tdubb123
Expert
Expert

these are realtime. host is 2 cpu and 8 cores/cpu. cpu util on the host is only at 10%

0 Kudos
iamamit
Enthusiast
Enthusiast

Looks like you have some VMs with unwanted resources over allocation. You should check the below KB and see if thats the case in your VM Infra.

Techies Sphere: VMware Virtual Machine's Resources Allocation Common Best Practices !

Thanks,

Amit

0 Kudos
tdubb123
Expert
Expert

this is from my esxi host.

for cpu ready and wait times should i be looking at VM or esxi host? or both?

0 Kudos
Dee006
Hot Shot
Hot Shot

Tdubb,

Are you getting any performance related issue in your VM level?

Do you have SRiov enabled in the host?

I've come across such incident due to weak storage,check any storage level bottleneck.

0 Kudos
tdubb123
Expert
Expert

no performance issues. but checking cpu ready and wait times. not sriov.

0 Kudos
iamamit
Enthusiast
Enthusiast

You should check both.. Smiley Happy

Why? ESXi host is responsible to provide compute resources to VMs (e.g. RAM, CPU) and VMs are responsible to run your applications using their allocated resources.

If the ESXi is overloaded or VMs are over-provisioned, both are going to create problem in Virtualisation. So, the conclusion is, you should check and balance both (VM and Esxi host) for better performance overall.

To find out overloaded host, you can check the performance of your ESXi hosts in the cluster and to check the over-provisioned Vms you can use the KB below:

http://www.techiessphere.com/2016/02/vmware-virtual-machine-resources.html

Thanks,

Amit

0 Kudos
tdubb123
Expert
Expert

al the VMs I have are dual cpu 4gb ram. same OS

I am just confused on why the physical cpu utlization is at 10% but the cpu ready and wait times are so high

0 Kudos
iamamit
Enthusiast
Enthusiast

I recommend you to read the below article to clear your confusion about low host usage and high ready usage case scenario. I am sure, It will be helpful..

http://www.joshodgers.com/2013/01/12/high-cpu-ready-with-low-cpu-utilization/

Overall what I can say is, you have to re-evaluate and analyse your VMs sizing. This may help you at every level of performance optimisation.

Thanks,

Amit

0 Kudos
tdubb123
Expert
Expert

so above what value is considered a bottleneck when looking at cpu ready and wait times or co-stop?

0 Kudos
iamamit
Enthusiast
Enthusiast

If its above 5.5 approximately.. It should be problematic..

Explained in below KB already provided in beginning our our conversation.. Smiley Happy

http://www.techiessphere.com/2016/02/vmware-virtual-machine-resources.html

0 Kudos