Storage Replica is one of the most pleasant surprises in Windows Server 10 Preview. Probably the fastest way to grasp the possibilities that you get with this feature is to see it in action - how it is configured and managed, and how you can use it in different disaster scenarios.
There are two main Storage replica setups:
- Server to Server replication
- Stretch Cluster
In this step-by-step screencast, we demonstrate the first case – Server to Server replication. In addition, we go through two main disaster scenarios – a Hard Disk failure and losing the entire source server.
As you will see, Storage Replica guarantees a valid mountable copy of a Data Volume that we can use to restore manually Data access for clients and applications. It is important to keep in mind that Storage Replica is dealing with storage blocks underneath the file system. In other words, we have Block-level replication of Data volumes, not single files. In addition, we need to have a set of two volumes – a Data volume and a Log volume, on the source and on the destination server.
Write operations are performed on the Log volume first, so you would definitely need a fast Solid State drive for that purpose. The replication process is using SMB3 transport; hence, the speed and reliability of the network connection between the servers is another crucial factor. Based on that factor, we can choose between:
- Synchronous replication – the source server is waiting for acknowledgement for each write IO, before data is committed to the Data volume, which guarantees no data loss.
- Asynchronous – over slower networks (ex. remote office). In this case, data is committed without acknowledgement, which can result in data loss.
In our demo, we configure and use synchronous replication. The fact that the replication process is totally oblivious to files being in use – it’s storage agnostic, allows us to use Storage Replica for:
- VM replication
- File Servers replication
- SQL Servers replication
- Any other (vendor approved) applications
We cannot use though Storage Replica for:
- Replication of system volumes and volumes with page files
- Exchange Servers (not supported)
- One-to-Many or Transitive (a-b-c) Replication
For your convenience, we provide the text file with our project plan and the commands that we are using in the screencast here