Vmware NBD restore speeds - What do you get.

Hey @ApK,

This might be useful - we have a tool that tests read/write performance of a datastore using the specified transport protocol.

Might help in your performance tuning endeavors. Its useful as it removes the disk read from the equation for testing restore scenarios etc.

Hi @Damian Andre.

Thanks for the above. I’m aware of the tool :-), but I’m just interested to hear from others, what they get of restore speeds.

At the moment I’m on lost ground on what can be expected from NBD restore. I can get a lot faster restore speeds from HotAdd.

Can you share any insights from Commvaults perspective, what do Commvault see when doing restores, what would be a good restore speed in respect to NBD?

Regards

-Anders

I don’t have any speeds to share (I’ll see if I can find an example), but I can say that NBD performance is throttled by ESX. The VMKernel port has a sort of quality of service function for NBD that means you never realize full network bandwidth - it wants to ensure availability for other services it provides.

Some say it taps out at around 100MB/sec - but perhaps could be more for multiple concurrent streams.

I don’t think we know quite what the rules and speeds are, as VMware has never officially disclosed it - but it has been tested and observed by other vendors as well.