Data center - Migrating storage from FC to IB, does this make sense?

Hello!

I work in a data center and we currently have 4-8 Gbit/s FC storage, all Brocade gear and IBM SVC controllers. Our workload is mostly HP blades running vSphere.

Since the setup is borderline legacy and becoming hard to maintain we had this thought: migrate to vSAN and use InfiniBand interconnects.

We've figured that:

• we can buy a IB HP blade to attach to the current systems running vSphere, around 300 € refurbished

• for non-blade systems, IB HBAs are pretty cheap, e.g. Mellanox ConnectX 2 goes for around 100 € refurbished

• we can get some cheap IB switches, e.g. the Mellanox IS5022 goes for around 200 € refurbished

• the real expense is cables, particularly longer runs which have to be active, we figured around 100 to 300 € per cable with QSFPs

We'll be running vSAN in all-flash configuration and we plan to transparently migrate the VMs for all nodes to the new setup (which means that for a while we'll have a hybrid FC/IB architecture).

Anyone went this route? Any pitfalls or obvious things we're missing?

Thanks