Scenarios of server cluster restore using Acronis Backup & Recovery
- Scenario 1: Cluster Disk Data Loss
- Scenario 2: Cluster Quorum Corruption
- Scenario 3: Cluster Disk Corruption or Failure
- Scenario 4: Cluster Quorum Disk Failure
- Scenario 5: Single Cluster Node Corruption or Failure
- Scenario 6: Cluster Quorum Rollback
- Scenario 7: Complete Cluster Failure
- Scenario 8: Majority Node Set Cluster Failure
For general information and on how the software backs up clusters see Work of Acronis Backup Software in a Clustered Environment.
If you have lost files and folders on one of your cluster disks, but not on the disk containing the cluster quorum, you can restore this data using Acronis backup software.
(!) You must restore the cluster disk data from the node that owns the cluster disk.
The cluster nodes can boot up, but the Cluster service fails to start because the quorum resource cannot come online.
If this problem results from corrupted files on the quorum disk, try starting the Cluster service by opening a command prompt and typing net start clussvc /resetquorumlog. This creates a new quorum log file, using information stored in the cluster database on the local node. For additional information about recovering from cluster quorum corruption, see Microsoft TechNet Article: Recover from a corrupted quorum log or quorum disk. If the cluster quorum disk needs to be replaced, see Scenario 5. For a majority node set cluster, see Scenario 8.
A cluster disk cannot come online. Resources that depend on that cluster disk will not be able to come online.
First, see if you can run a diagnostic utility from the disk manufacturer to determine the condition of the disk. If the cluster disk is corrupted or the disk hardware fails, you can restore the disk more quickly by using image restore:
- If necessary, replace the cluster disk. For information, see Microsoft TechNet Article: Install local storage buses and devices.
- Stop the Cluster service on all nodes of the cluster.
- Locate the disks\volumes backup set for the node that owns the cluster disk. Perform an image restore on a node. After the restored node comes back online, restart the Cluster service on the remaining nodes.
The cluster nodes can boot up, but the Cluster service fails to start because the quorum resource cannot come online. Entries in the Event Log indicate hardware failures.
First, try starting the Cluster service by opening a command prompt and typing net start clussvc /fixquorum. This starts the Cluster service with all resources offline, including the quorum resource. Then you can try switching to a new quorum resource.
If the cluster quorum disk (the disk containing the quorum resource) fails, you can replace it:
- If necessary, replace the cluster quorum disk. For information, see Microsoft TechNet Article: Install local storage buses and devices.
- Locate the disks\volumes backup set for the cluster quorum. Perform an image restore on any node in the cluster.
- Restore data on the node.
The node cannot join the cluster.
If the Event Log indicates that the cluster database on the local node is corrupted, you can perform a System State restore on that node to replace the local cluster database. Alternatively, you can copy the latest checkpoint file (CHKxxx.TMP) from the quorum disk to the %systemroot%\Cluster\ directory, rename it as file CLUSDB, and restart the Cluster service on that node.
If a single node fails in the cluster due to system disk or other hardware failure, follow these steps to rebuild the node and rejoin the cluster:
- After verifying that all cluster resource groups have been successfully moved to other nodes, repair or replace the failed hardware. For information, see Microsoft TechNet Articles: Move a group to another node and Manage Cluster Hardware.
- Perform a disks\volumes image restore on the failed node to rebuild the node.
- If you have other files or application data for that node backed up on a tape or other backup medium, you can restore that now.
- For each cluster group and resource, verify that the newly recovered node appears as a possible owner in Cluster Administrator, then move a resource group to the newly recovered node and verify that the move is successful. For information, see Microsoft TechNet Article: Test whether group resources can fail over.
- You can evict that node and add a new node to the cluster. For more information, see Microsoft TechNet Articles: Evict a node from the cluster and Add additional nodes to the cluster.
If recent changes to your cluster have resulted in the cluster not functioning as expected, you can use the restore wizard of Acronis backup software to roll back your cluster to a previous configuration. For example, if a number of resources have mistakenly been deleted from the cluster configuration, you can roll it back, using a backup that contains those resources.
None of the nodes can boot up.
If all nodes fail in a cluster and the quorum disk cannot be repaired, follow these steps:
- Use disks\volumes image restore on one node in the original cluster, choosing a node that was backed up recently and that was active in the cluster at the time it was backed up. Do not start other nodes until the first node is restored.
- Restore other nodes from the respective disks\volumes backup sets.
- Restore your more recent applications and application data from data backup sets if necessary.
(!) If you do not have a disks\volumes backup of each node, you cannot restore the cluster. Instead, you must recreate your cluster from scratch. For more information, see Microsoft TechNet Article: Checklist: Planning and creating a server cluster.
The methods for restoring a majority node set cluster are the same as for restoring other clusters. However, in a majority node set cluster, if some of the nodes fail, and the cluster loses quorum, you can force the remaining nodes to form a quorum and restart the cluster. For more information, see Microsoft TechNet Article: Force quorum in a majority node set server cluster.
- On a majority node set cluster, the cluster database is not stored on a cluster disk central to all nodes, but is instead stored locally on each node at %systemroot%\Cluster\MNS.%ResourceGUID%$\%ResourceGUID%$\MSCS\.
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