Thanks for the question, Venkat.
Asked: August 17, 2016 - 10:55 am UTC
Last updated: August 18, 2016 - 2:46 am UTC
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Hi Top,
We have a new project proposal to migrate the databases from physical servers to VM. When compared to physical servers, VM servers will have some performance impact. I need some information on finding the pre-requisites:
1. What are performance bottlenecks that need to be considered?
2. How to calculate the required cpus needed on the VM?
3. Is the same size of RAM is enough on VM or does it need more in the VM?
4. How can we calculate the IO? any tools for that?
Please provide information or reference for the above.
Thanks,
Venkat
and Connor said...
There are different *kinds* of virtualisation but the overheads of VM continue to shrink so that VM's run very close to bare metal performance.
Most VM problems occur when people try to run tens or hundreds or thousands of VM's on a single physical box, and then wonder why they've run into problems :-)
So if your physical box had 'x' CPU's, and 'y' RAM, then your VM can be configured with similar settings, and you should near the same the performance/throughput.
But please...dont take my word for it. If you are moving platforms...the most critical thing is *always* to benchmark, benchmark, benchmark. Don't assume...dont guess...get the real measurements.
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