VMware Networking Blog

At VMworld last year, F5 previewed and demonstrated their Long Distance vMotion solution. Since then, F5 has worked on integrating the solution into their BIG-IP product and leverage their new WAN Optimization Module (WOM).

What does this mean for VMware customers?

vMotion over distance on a traditional WAN is constrained by bandwidth and latency. Any packet loss will further throttle throughput as TCP congestion avoidance kicks in. In short distance and bandwidth constrains how far you go and how much you can pump through the link (and how many VMs you can migrate in a unit of time).

The F5 solution does a few things—it encrypts and compresses the data (i.e. less bits to send and it’s secure!); and it optimizes the transmission so it’s less susceptible to packet loss. The BIG-IP solution also automatically redirects the session to the new site.

The end result is a huge acceleration and increased success rate for Long Distance vMotions. Nojan published a table of results on the F5 DevCentral blog that showed a 3.1x to 4.7x improvement in time. e.g. vMotion time over a 1Gbps link with 20ms RTT dropped from 2:38 to 0:38. Another test over a tiny T3 link with 100ms RTT (that’s a loooonnng way) dropped from 13:43 to 3:35 with an increase in reliability of vMotion completions from <50% to 100%.

More info

F5 has produced a raft of information to help you understand and implement the solution.

• Press Release is here (with links to other resources)    
• DevCentral Blog entry with demo video are here (I highly recommend watching the video)
• Deployment Guide is here (30-page how-to guide on LD vMotion with vSphere)