Hiya folks, Ned here again. Windows Server 2016 Technical Preview 5’s release brings you a number of new Storage Replica features, some of which we added directly from your feedback during the preview loop:
- Asynchronous stretch clusters now supported
- RoCE V2 RDMA networks now supported
- Network Constraint
- Integrated with the Cluster Health service
- Thin provisioned storage now supported
- Fixes aplenty
As you recall, Storage Replica offers new disaster recovery and preparedness capabilities in Windows Server 2016 Technical Preview. For the first time, Windows Server offers the peace of mind of zero data loss, with the ability to synchronously protect data on different racks, floors, buildings, campuses, counties, and cities. After a disaster strikes, all data will exist elsewhere without any possibility of loss. The same applies before a disaster strikes; Storage Replica offers you the ability to switch workloads to safe locations prior to catastrophes when granted a few moments warning – again, with no data loss. It supports three scenarios in TP5: stretch cluster, cluster-to-cluster, and server-to-server.
Sharp-eyed readers might notice a certain similarity to Claus’ “What’s new in Storage Spaces Direct Technical Preview 5” blog post. Does my content directly rip off its style and flow, making me a thief and a cheater?
Yes. Yes, it does.
Asynchronous stretch clusters now supported
You can now configure stretch clusters over very high latency and lower bandwidth networks. This means all three SR scenarios support both synchronous and asynchronous now. By default, all use synchronous unless you say otherwise. And we even included a nice wizard option for those using Failover Cluster Manager:
RoCE V2 RDMA networks now supported
You are now free to use RDMA over Converged Ethernet (RoCE) V2 in your deployments, joining iWARP and InfiniBand + Metro-X as supported network platforms. Naturally, plain old TCP/IP is still fine. Naturally, you will probably not be replicating great distances with RoCE due to its inherent nature, but datacenter and campus-wide is very attainable.
You won’t have to do anything in SR to make this work at RTM*, it just happens by getting RoCEv2 to work, just like the other protocols. This is the beauty of SMB 3, the transport protocol for SR – if it finds working RDMA paths, it uses them along with multichannel, for blazing low latency, high throughput perf. You don’t have storage fast enough to fill SMB Direct. Yet…
* In TP5 multichannel needs a little nudge
You asked for it, you got it: you can now control which networks SR runs upon, based on network interface. We even support doing this per replication group, if you are a mad scientist who wants to replicate certain volume on certain networks.
Usage is simple – get the replication group and network info on each server or cluster:
Set-SRNetworkConstraint -SourceComputerName <hi> -SourceRGName <there> -SourceNWInterfaceIndex <7> -DestinationComputerName <you> - -DestinationRGName <guys> DestinationNWInterfaceIndex <4>
Integrated with the Cluster Health service
Windows Server 2016 TP5 contains a brand new mechanism for monitoring clustered storage health, with the imaginative name of “Health Service”. What can I say; I was not involved. Anyhoo, the Health Service improves the day-to-day monitoring, operations, and maintenance experience of Storage Replica, Storage Spaces Direct, and the cluster. You get metrics, faults, actions, automation, and quarantine. This is not turned on by default in TP5 for mainline SR scenarios yet, I just want you knowing about it for the future.
How do you feel about adding users to the built-in administrators group on your servers? Hopefully queasy. Storage Replica implements a new built-in group for users to administer replication, with all the necessary ACLs in our service, and driver, and registry. By adding the user to this group and Remote Management Users, they now have the power to replicate and remotely manage servers – but nothing else.
And just to make it easy, we gave you the Grant-SRDelegation cmdlet. I hate typing.
Thin provisioned storage now supported
By popular demand, we also added replication support for thin-provisioned storage. You can now use SAN, non-clustered Storage Spaces, and dynamic Hyper-V disk for thin-provisioned storage with Storage Replica. This means the initial sync of new volumes is nearly instantaneous.
Don’t believe me? Ok:
Did you blink and miss it? Initial sync completed in less than a second.
Finally, there have plenty of fixes and tweaks added, and more to come. For instance, PowerShell has been improved – look for the
-IgnoreFailures parameter when you are trying to perform a direction switch or replication tear down and a node is truly never coming back.
This is a continual improvement process and we very much want to hear your feedback and your bugs. Email email@example.com and you will come right into my team’s inbox. You can also file feedback at our UserVoice forum. As always, the details, guides, known issues, and FAQ are all at https://aka.ms/storagereplica.
Until next time,
– Ned “getting close” Pyle