Faster Live Migration–Which Option Should You Choose?

Okay, now that I have talked about faster live migration with compression and faster live migration with RDMA – one of the first questions that comes to mind is: which option is right for you?

When we were developing Hyper-V in Windows Server 2012 R2 we did a lot of testing to try and come up with an answer to this question – and the answer is surprisingly simple.  All you need to know is: how much network bandwidth do you have available for live migration?

If it is 10gbit or less – use live migration with compression.

If it is greater than 10gbit – use live migration with RDMA.

It does not matter if you are using 1gbit, 10gbit or 40gbit network connectivity – this guidance still holds.  It actually does not matter if you have RDMA support or not.  If you have over 10gbit network connectivity available for live migration – live migration over RDMA will get better performance thanks to SMB multichannel support.

Cheers,
Ben

Comments

• Anonymous
  January 09, 2014
  Hey Ben, can you please explain what your testing results are and why we should NOT use SMB multichannel when we have for example only 4x 1Gbit NICs? In my current lab with a 3-Node 2012-R2 Cluster I of course tested both technologies ;) Yes, compression is nice, but in my testing with 4x 1Gbit NICs and live migration over SMB Multichannel it was: a) stable b) twice as fast!? Thx for your post! Cheers, Flo.