A fairly attention-grabbing characteristic, Storage Replica (SR), appeared in Windows Server 2016 that permits to copy the native disk quantity to a distant server for catastrophe restoration. Volume information are robotically synchronized over your community to a secondary server the place the an identical copy of your quantity will at all times be out there. In Storage Replica, the information are replicated on the block degree over the SMB v3.1 protocol independently of the file system sort used (NTFS, CSVFS, ReFS).
Storage replication in Windows Server 2016 works in Active/Passive mode. It signifies that the information can be found solely on the supply server. There are two replication modes:
- Synchronous replication – the information are written to each servers concurrently. Prior to writing the information, the first server is ready for the writing affirmation from the distant server (present zero information loss on the file system throughout a failure inside a low-latency community).
- Asynchronous replication – the information are written to the first server after which replicated to the secondary one (can be utilized to copy information on a high-latency community, however with out assure of an identical copies of knowledge in case of failure).
Storage Replica helps the next situations:
- Replication between the native volumes of the server;
- Server-to-server storage replication;
- Storage replication within the stretch cluster;
- Cluster-to-cluster storage replication.
Storage Replica Prerequisites
To use Storage Replica, your infrastructure should meet the next necessities:
- Windows Server 2016/2019 Datacenter version;
- Both servers should be joined to the Active Directory area;
- Each server should have two extra drives: one for information, the opposite one for logs. The log drive should be quicker than the information drive, ideally, it’s an SSD. The information drive sizes should be the identical;
- GUID Partition Table (GPT) format on a bodily disks (MBR will not be supported);
- Local drives (SAS/SCSI/SATA), iSCSI, SAN, , on SAS JBOD are supported;
- At least 2GB of free RAM on the server;
- The community throughput between the server should be no less than 1 Gbit/s with lower than 5 ms latency in each methods. (As a rule, this limits the gap between the replication companions to 20-50 km.) It is beneficial that the community adapter helps RDMA;
- Open TCP ports 445, 5985 and 5445 between the servers.
Installing Storage Replica Feature on Windows Server 2016
You can set up the Storage Replica characteristic on Windows Server 2016/2019 from the Server Manager console or utilizing PowerShell:
Install-WindowsFeature Storage-Replica –IncludeManagementTools -Restart
Install the Storage-Replica characteristic on each servers. When you might be prepared, restart your servers.
How to Configure Volume Replication on Windows Server 2016?
Storage Replication doesn’t have an built-in graphical administration console. To configure storage replication, you should use PowerShell, Windows Admin Center or Failover Clustering console (in case you are utilizing the cluster).
You can show the record of obtainable PowerShell cmdlets within the StorageReplica module as follows:
Get-Command -Module storagereplica
Using the Test-SRTopology command, you can also make certain in case your server and netwok meet the Storage Replica necessities. You can estimate the present variety of I/O operations, community throughput, log sizes. The Test-SRTopology cmdlet generates an HTML report with present masses and proposals.
Enable the replication of D: drive between two separate servers Server1 and Server2 (Disk L: is used for logs, the log measurement is 1GB.):
New-SRPartnership -SourceComputerName Server1 -SourceRGName Server1ReplGr01 -SupplyVolumeIdentify E: -SourceLogVolumeIdentify L: -DestinationComputerName Server2 -DestinationRGName Server2ReplGr01 -Vacation spotVolumeIdentify D: -DestinationLogVolumeIdentify E: -LogSizeInBytes 1GB
After you allow replication on the secondary server, the information disk turns into unavailable for direct entry (RAW format).
You can get extra quantity replication info utilizing the extra efficiency counters in or from PowerShell:
Get-Counter -Counter “Storage Replica Statistics
You can monitor the amount replication occasions utilizing the Event Viewer (Applications and Services Logs -> Microsoft -> Windows -> StorageReplica) or from PowerShell:
Get-WinEvent -ProviderName Microsoft-Windows-StorageReplica -max 20
You can change the replication mode to asynchronous utilizing this command:
Set-SRPartnership -ReplicationMode Asynchronous
In case of major server failure, you’ll be able to manually change the path of knowledge replication by placing the secondary copy on-line:
Set-SRPartnership -NewSourceComputerName Server2 -SourceRGName Server2ReplGr01 -DestinationComputerName Server1 -DestinationRGName Server1ReplGr01
To get the replication group state and the path of replication, use the Get-SRGroup and Get-SRPartnerShip cmdlets.
You can view the size of the copy queue:
(Get-SRGroup).Replicas | Select-Object numofbytesremaining
To disable the storage replication:
Get-SRPartnership | Remove-SRPartnership (on the first server solely)
Get-SRGroup | Remove-SRGroup (on each servers)
Many firms use DFS replication between datacenters as an answer to copy information storage. SR has some benefits over DFS replication: the information are copied on the block degree (replication of open or in-use information, in addition to VSS snapshots is feasible); database independence; quick and synchronous replication (no want to attend for hours or days like in DFS). However, SR has some disadvantages: solely 1-to-1 replication; excessive community throughput and latency necessities; and not using a cluster, the path of the replication is switched manually, in addition to reconfiguration of apps (customers) to a brand new server (you’ll be able to simplify it by utilizing frequent DFS namespace).
In Windows Server 2019 Build 17650, Storage Replica is out there within the Standard version as nicely (you’ll be able to replicate just one quantity as much as 2TB to 1 replication associate). In addition, the Test Failover mode has appeared. In this mode, a associate reproduction quantity is writable, and the replication stops till the Test Failover mode is disabled (all modifications made on this mode are rolled again to the snapshot).