What is the ‘Replication State’ and what are the values?

Replication state shows the current state of the replicating VM. It indicates whether the VM is being replicated, whether initial replication is pending etc.

ReplicationState can be queried from:

  • UI – As seen in the above picture
  • PowerShell – Using the Measure-VMReplication cmdlet.
  • WMI – From Msvm_ComputerSystemclass where      ReplicationState is a property

The table below captures the states as seen in WMI, UI and PowerShell.

WMI

UI

PowerShell

Notes

0

Not enabled

NA

VM is not   enabled for replication.

1

Pending Initial   Replication

ReadyForInitialReplication

Replication relationship has been created but Initial Replication   has not been initiated. This is seen on the primary VM only.

2

Pending Initial   Replication

WaitingForInitialReplication

The replica VM enters this state when a replication   relationship has been created but Initial   Replication has not been initiated (or) Initial Replication   is in progress.

The primary VM enters this state when Initial Replication   is in progress.

3

Replication Enabled

Replicating

This state (on  both the primary and replica VM)   indicates that the replication is ‘Normal’.

4

Prepared for planned   failover

SyncedReplicationComplete

This state is applicable only for the primary VM. It indicates   that Planned   Failover is complete and that the VM is locked from powering   up.

5

Failover Complete

FailOverWaitingCompletion

Failover has been initiated on the   replica VM but has not been completed. The Failover operation is considered   to be complete only when the VM is either reverse replicated (or) when   additional recovery points are removed.

6

Failover Complete

FailedOver

The replica VM enters this state once the Failover   operation has been completed.

7

Replication Paused

Suspended

The VM enters this state when replication is Paused. This   state is applicable on both the primary and replica VM

8

Replication Error

Error

This state is applicable on both the primary and replica VM   and indicates that replication is not occurring on either VM. Usually   administrator intervention is required to restore replication.

9

Resynchronization required

WaitingForStartResynchronize The primary VM enters this state when it needs to be   resynchronized.

10

Resynchronizing

Resynchronizing

Resynchronization has been initiated on the primary VM.

11

Resynchronize Suspended

ResynchronizeSuspended

If the primary VM suspends the resynchronization

Storage and Continuous Availability Enhancements in Windows Server 2012

Windows Server 2012 will provide a continuum of availability options to protect against a wide range of failure modes in different tiers – storage, network, and compute. These options will enable higher levels of availability and cost-effectiveness, as well as easier deployment for all customers – from small business to mid-market to enterprises – and across single servers, multiple servers, and multi-site cloud environments. Windows Server 2012delivers on continuous availability by efficiently utilizing industry standard storage, network and server components. That means many IT organizations will have capabilities they couldn’t previously afford or manage.

SMB 2.2 transparent failover, along with SMB 2.2 Multichannel and SMB 2.2 Direct, enables customers to deploy storage for workloads such as Hyper-V and SQL Server on cost efficient, continuously available, high performance Windows Server 2012 File Servers.

Below are some of the key features we’re delivering in Windows Server 2012 involving SMB 2.2.

  • Transparent Failover and node fault tolerance with SMB 2.2. Supporting business critical server application workloads requires the connection to the storage back end to be continuously available. The new SMB 2.2 server and client cooperate to provide transparent failover to an alternative cluster node for all SMB 2.2 operations for both planned moves and unplanned failures.
  • Fast data transfers and network fault tolerance with SMB 2.2 Multichannel. With Windows Server 8, customers can store application data (such as Hyper-V and SQL Server) on remote SMB 2.2 file shares. SMB2.2 Multichannel provides better throughput and multiple redundant paths from the server (e.g., Hyper-V or SQL Server) to the storage on a remote SMB2.2 share. Network path failures are automatically and transparently handled without application service disruption.
  • Scalable, fast and efficient storage access with SMB2 Direct. SMB2 Direct (SMB over RDMA) is a new storage protocol in Windows Server 8. It enables direct memory-to-memory data transfers between server and storage, with minimal CPU utilization, while using standard RDMA capable NICs. SMB2 Direct is supported on all three available RDMA technologies (iWARP, InfiniBand and RoCE.) Minimizing the CPU overhead for storage I/O means that servers can handle larger compute workloads (e.g., Hyper-V can host more VMs) with the saved CPU cycles.
  • Active-Active File sharing with SMB 2.2 Scale Out. Taking advantage of the single namespace functionality provided by Cluster Shared Volumes (CSV) v2, the File Server in Windows Server 2012can provide simultaneous access to shares, with direct I/O to a shared set of drives, from any node in a cluster. This allows utilization of all the network bandwidth into a cluster and load balancing of the clients, in order to optimize client experience.
  • Volume Shadow Copy Service (VSS) for SMB 2.2 file shares. Remote VSS provides application-consistent shadow copies for data stored on remote file shares to support app backup and restore scenarios.

Alongside the SMB 2.2 Server implementation in Windows Server 2012, Microsoft is working with two leading storage companies, NetApp and EMC, to enable them to fully integrate SMB 2.2 into their stacks and provide Hyper-V over SMB 2.2 solutions. Having NetApp and EMC on board not only demonstrates strong industry support of SMB 2.2 as a protocol of choice for various types of customers, but also highlights how the industry is aligned with our engineering direction and its support for our Windows Server 2012 storage technology.