vSphere vs Hyper-V showdown - Results - Individual VM Disk

Results - Individual VM Disk

Today I’ll be looking at the results for individual VM Disk.

Write out a 512mb file.

 

You can see that vSphere took a little longer than Hyper-V to write.

The next step was to read in the 512 MB file, and I think there was a lot of caching going on with this sequential read.

 

Read the 512 MB file

 

 

There is a noticeable anomaly, but the absolute numbers are small and read times are pretty quick. I believe this would need more sampling to see how much variability exists.

 

The final disk test was an intensive random I/O script that looped through reading and writing  with the 512mb file. This one definitely had a negative impact on Hyper-V.

 

 

 

I call the performance abysmal for Windows on Hyper-V as it essentially just ‘fell over’. Dynamic disks were configured for the VMs, and after this surprise result some research turned up a recommendation from Microsoft that static disks should be used for random I/O. These test results are a good illustration of why benchmarking is important. Bear this in mind and create static disks up front for random I/O until this issue is confirmed to be resolved. I attempted to convert the dynamic disks to static and the wait time was longer than my patience.

 

Summary of disk I/O results

Random I/O on a Hyper-V dynamic disk had terrible performance, so remember to create static disks.

 

On Friday I'll be showing you the test results for Individual VM Memory.

 

Dale Feiste

Consultant