VM sluggish performance

[balothia]

Hi All,

Has any one seen VM Sluggish performance and it got resolved by vMotion?.

Recently i got a call for sluggish performance on a VM, its a RedHat Linux VM i used top and all other tools to identify the issue but nothing came out. Majorly on the VM if I run the top command it was hanging, shell prompt was slow. But as per the output of top, vmstat, ping command there were no issues. I just vMotioned the VM and it resolved the issue, now the same VM is performing well.

Thanks,

Gautam Balothia

[joshodgers]

Hi Guatam,

A simple thing you can do during problem determination is a vMotion top eliminate the source host, so I have seen this many times.

The interesting test is if you vMotion off one host, and performance improves, then you vMotion back and performance remains improved.

I have seen many cases where things like SDRS/DRS had recently performed an operation which has moved contention from one host to another, although improving the issue, not truly solving it in highly overcommited environments.

The other factor i see regularly is VMs having "burst" workloads or scheduled tasks (such as SQL roll-up jobs), which can impact performance for a short time, and a vMotioning off the host with the burst workload can help with performance.

While im giving high level examples of when vMotion can help, most of the time there is contention somewhere which can be easy to overlook when investigation. so doing a vMotion is a quick/easy step to try and troubleshoot performance issues which I recommend to vSphere admins.

Hope that helps

[balothia]

Many Thanks Joshodgers... same is my experience as well. Just want to confirm if in vSphere 5.0 somebody is facing this issue. I know many clients are facing this issue in 4.x.

Thanks,

Gautam