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SnapManager for Hyper-V

Reconfigure storage systems after a disaster recovery failback

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After failing over to a secondary storage system, SnapManager for Hyper-V completes disaster recovery by failing back to the original primary storage system. Failing back restores primary storage function to the original primary storage site after its storage systems are reenabled or replaced.

Steps

  1. Depending on the condition of the primary storage system, take one of the following actions:

    If the primary storage system is…​ Then…​

    Recoverable

    Move the data from the secondary host back to the primary storage system.

    Completely destroyed

    Provision a new storage system.

  2. Manage the SnapMirror relationship:

    1. Initialize the SnapMirror relationship from the secondary storage system to the primary storage system to recover the data.

    2. Resynchronize the existing SnapMirror relationship from the secondary storage system to the primary storage system.

    3. Using SnapDrive on the secondary storage system, initiate a SnapMirror update for each of the LUNs or SMB shares on the secondary storage system.

  3. Depending on your configuration, take one of the following actions:

    If the primary storage system is…​ Then…​

    A stand-alone host (SAN)

    Connect to all the mount points and LUNs on the primary storage system of the same type.

    A clustered host (SAN)

    From the node where the cluster group is online, connect to all the mount points and LUNs in the cluster.

    Data ONTAP 8.1.x configured with a single LUN hosting VMs on a source FlexVol volume (SAN)

    For SnapMirror updates to succeed, you must create a second, smaller LUN (10 MB to 100 MB) on the source FlexVol volume before initiating a backup job. From the node where the cluster group is online, connect to all the mount points and LUNs in the cluster.

    A stand-alone or clustered host (NAS)

    Unmount the Data Protection (DP) volume, mount the DP volume as rewriteable, verify that the volume has RWX permissions, and then create CIFS shares for the different volumes.

  4. Reconfigure SnapInfo based on your environment:

    If your configuration is…​ Then…​

    SAN

    Restore the SnapInfo LUN from its last Snapshot copy.

    NAS

    Mount the SnapInfo directory.

    For NAS, if an access is denied error occurs, or if you cannot browse to the exposed SMB share location, you might need to reset the ACL on the share.

  5. Add the primary host or cluster in SnapManager for Hyper-V MMC and configure it with the SnapInfo path.

  6. Enter the following cmdlets:

    1. Retrieve the list of VMs present in the backup metadata by using the Get-VMsFromBackup cmdlet.

    2. Get the backup copies for each VM by using the Get-Backup cmdlet to get the backup copies for each VM.

  7. To restore, use Restore-Backup with the VM GUID and the backup copy with the following parameters:

    To restore from…​ Enter this command…​

    An alternate host

    Restore-Backup -Server Secondary_host_system_or_cluster_name -DisableVerifySnapshot -RestoreToAlternateHost

    A listed backup copy

    Restore-Backup -Server -VirtualMachinePath -SnapShotFilePath @VHD

    For @VHD, a VM might have multiple VHDs; you must enter both a source and a destination path pair specified for each VHD.

  8. If the secondary host system is a cluster, complete the following steps:

    1. Ensure that the LUNs on which the VMs reside are online on the cluster node that owns the cluster group.

    2. Use the failover PowerShell cmdlets to make the VMs highly available.

    For NAS, after the VMs are exposed as SMB shares from one cluster node, the VMs are accessible to all hosts configured to use the storage system cluster.

Failback examples

The following example shows a two-cluster setup in which smhv-cluster-01 is the primary site and hv-19-cluster is the secondary site:

PS C:\> Get-VMsFromBackup -Server smhv-cluster-01

winxp-x64c-135                593ABA72-B323-4AF7-9AC6-9514F64C0178
csv1-xp-3                     59B85C68-BAFA-4A49-8E85-A201045843F7
vm-w2k8r2sp1                  5A248757-872B-4FE7-8282-91C8E9D45CF9
um10_11_dr                    5AC1B2A8-6603-4F90-98F5-4F2F435AB0C2
winxp-x64c-30                 5B47D3CF-5D96-495D-9BAB-FB394392CF31
winxp-x64c-126                5B57EED1-B4F1-45A3-A649-24C6947CB79C
winxp-x64c-118                5B5D417B-70DC-427C-94BB-97FF81C5B92B
winxp-x64c-122                5BEE26B8-BE57-4879-A28E-9250A6A5EEFC
csv4-w2k3-19                  5D0613E5-B193-4293-8AAD-F8B94A5D851F

PS C:\> Get-Backup -Server smhv-cluster-01 -ResourceName
um10_11_dr

BackupName    : smhv-ccb-ds_04-10-2012_10.37.58
RetentionType : hourly
DatasetName   : smhv-ccb-ds
BackupId      : smhv-ccb-ds_04-10-2012_10.37.58
BackupTime    : 4/10/2012 10:37:58 AM
BackupType    : Application consistent
BackedupVMs   : {um10_11_dr}

PS C:\> Restore-Backup -Server smhv-cluster-01 -ResourceName
um10_11_dr -BackupName smhv-ccb-ds_04-10-2012_10.37.58
-DisableVerifySnapshot -RestoreToAlternateHost

The following example shows a SAN restore operation to an alternate path for which N:\ is the destination and I:\ is the source LUN path:

PS C:\> Restore-Backup -Resourcename dr-san-ded1
-RestoreToAlternateHost -DisableVerifySnapshot -BackupName san_dr_09-11-2013_10.57.31 -Verbose
-VirtualMachinePath "N:\dr-san-ded1" -SnapshotFilePath "N:\dr-san-ded1" -VHDs @(@{"SourceFilePath" = "I:\dr-san-ded1\Virtual Hard Disks\dr-san-ded1.vhdx"; "DestinationFilePath" = "N:\dr-san-ded1\Virtual Hard Disks\dr-san-ded1"})

The following example shows a NAS restore operation to an alternate path for which \\172.17.162.174\ is the source SMB share path and \\172.17.175.82\ is the destination SMB share path:

PS C:\> Restore-Backup -Resourcename vm_claba87_cifs1
-RestoreToAlternateHost -DisableVerifySnapshot -BackupName ag-DR_09-09-2013_16.59.16 -Verbose
-VirtualMachinePath "\\172.17.175.82\vol_new_dest_share\ag-vm1" -SnapshotFilePath "\\172.17.175.82\vol_new_dest_share\ag-vm1" -VHDs @(@{"SourceFilePath" = "\\172.17.162.174\vol_test_src_share\ag-vm1\Virtual Hard Disks\ag-vm1.vhdx"; "DestinationFilePath" = "\\172.17.175.82\vol_new_dest_share\ag-vm1\Virtual Hard Disks\ag-vm1.vhdx"})

Related information

Data ONTAP 8.2 Data Protection Online Backup and Recovery Guide for 7-Mode

SMB/CIFS Reference