Windows Server 8 Hyper-V Replica … In Detail

17Mar/120

Windows Server 8 Hyper-V Replica … In Detail

Replica (Hyper-V Replica) is a built-in software based asynchronous replication mechanism that has been designed to solve these problems. This is what Microsoft envisioned for Replica.

If you asked me to pick the killer feature of Windows Server 8 Hyper-V, then Replica would be high if not at the top of my list (64 TB VHDX is right up there in the competition). In Ireland, and we’re probably not all that different from everywhere else, the majority of companies are in the small/medium enterprise (SME) space and the vast majority of my customers work exclusively in this space. I’ve seen how DR is a challenge to enterprises and to the SMEs alike. It is expensive and it is difficult. Those are challenges an enterprise can overcome by spending, but that’s not the case for the SME.

Virtualisation should help. Hardware consolidation reduces the cost, but the cost of replication is still there. SAN’s often need licenses to replicate. SAN’s are normally outside of the reach of the SME and even the corporate regional/branch office. Software replication which is aimed at this space is not cheap either, and to be honest, some of them are more risky than the threat of disaster. And let’s not forget the bandwidth that these two types of solution can require.

Isn’t DR Just An Enterprise Thing?

So if virtualisation mobility and the encapsulation of a machine as a bunch of files can help, what can be done to make DR replication a possibility for the SME?

Enter Replica (Hyper-V Replica), a built-in software based asynchronous replication mechanism that has been designed to solve these problems. This is what Microsoft envisioned for Replica:

If you need to replicate dozens or hundreds of VMs then you should be using a SAN and SAN replication. Replica is not for the medium/enterprise sites.
Smaller branch offices or regional offices that need to replicate to local or central (head office or HQ data centre) DR sites.
SME’s who want to replicate to another office.
Microsoft partners or hosting companies that want to offer a service where SME’s could configure important Windows Server 8 Hyper-V host VMs to replicate to their data centre – basically a hosted DR service for SMEs. Requirements of this is that it must have Internet friendly authentication (not Kerberos) and it must be hardware independent, i.e. the production site storage can be nothing like the replica storage.
Most crucially of all: limited bandwidth. Replica is designed to be used on commercially available broadband without impacting normal email or browsing activity – Microsoft does also want to sell them Office 365, after all How much bandwidth will you need? How long is a piece of string? Your best bet is to measure how much change there is to your customers VMs every 5 minutes and that’ll give you an idea of what bandwidth you’ll need.