Protecting a GeoCluster

1. Select Start, Programs, Administrative Tools, Cluster Administrator.
2. Right-click the group that you want to add a replicated disk to and select New, Resource.
3. Specify the following fields on the New Resource dialog box.

• Name—Specify a name that identifies which application, file set, disk, and so on that you are protecting. This name must be unique within the cluster.
• Description—You can optionally add a more detailed description for this resource.
• Resource type—Specify GeoCluster Replicated Disk.
• Group—The group that you originated the new resource from will be selected. Verify that this is the correct group. If it is not, select the correct group name.

4. Click Next to continue.
5. The GeoCluster Replicated Disk resource ensures that an up-to-the-minute copy of the data resides on all nodes identified in the Possible owners list. All nodes are included in the default, which should not be changed. Click Next to continue.
6. The GeoCluster Replicated Disk resource is not dependent on any other resources. Click Next to continue.
7. Specify the GeoCluster Replicated Disk parameters using the settings below.

• Disk to replicate—Select a disk to replicate from the available volumes. The only volumes that will be displayed are those that meet the following criteria.
• NTFS volumes
• Volumes which are not already being replicated by another GeoCluster Replicated Disk resource
• Volumes that are not physical disk resources
• Volumes that do not contain system files (The volume that you booted Windows from will not be displayed.)
• Volumes that exist on all nodes of the cluster
• Network—Select the network that you want to use for Double-Take Availability mirroring and replication traffic. If you do not have multiple networks established, you will only be able to select the one network that does exist. If you do not select a network, Double-Take Availability will use DNS to determine a network route to use. Ideally, the networks used for various traffic should be separated. This is dependent on the number of networks that you established when you created the cluster and the priority assigned to each network. For example, if you have two network routes, separate Double-Take Availability and your public traffic. If you have three routes, separate the public traffic and then separate Double-Take Availability from the cluster heartbeat.
• Orphan files—An orphan is a file that exists in the target location but is not in the source location. You can enable the resource to remove or delete orphans during a mirror. If you choose to move orphan files, specify the location where you want to move them. You should not select the system volume for the orphan files because it could impact the stability of the cluster service.

8. Click Next to continue.
9. If you want to configure compression, verify that Enable Compression is selected. Depending on the compression algorithms available for your operating system, you may see a slider bar indicating different compression levels. Set the level from minimum to maximum compression to suit your needs.
10. Click Next to continue.
11. Specify your Double-Take Availability mirroring settings.

• Full Mirror—All files in the replication set will be sent from the source to the target.
• File differences—Only those files that are different based size or date and time will be sent from the source to the target.
• Send data only if Source is newer than Target—Only those files that are newer on the source are sent to the target.

Note:

If you are using a database application, do not use the newer option unless you know for certain you need it. With database applications, it is critical that all files, not just some of them that might be newer, get mirrored.

• Use block checksum—For those files flagged as different, the mirror performs a checksum comparison and only sends those blocks that are different.
• Calculate Replication Set size prior to mirror—Determines the size of the replication set prior to starting the mirror. The mirroring status will update the percentage complete if the replication set size is calculated.

8. Click Finish to complete the creation of the GeoCluster Replicated Disk resource.

1. Select Start, Programs, Administrative Tools, Failover Cluster Management.
2. Right-click the application group where you want to add a replicated disk to and select Add a resource, More resources, Add GeoCluster Replicated Disk.
3. Right-click on the resource and select Properties.
4. On the Connection Parameters tab, specify the GeoCluster Replicated Disk connection parameters using the settings below.

• Disk to replicate—Select a disk to replicate from the available volumes. The only volumes that will be displayed are those that meet the following criteria:
• NTFS volumes
• Volumes which are not already being replicated by another GeoCluster Replicated Disk resource
• Volumes that are not physical disk resources
• Volumes that do not contain system files (The volume that you booted Windows from will not be displayed.)
• Volumes that exist on all nodes of the cluster

Note:

If you are using Hyper-V, select the drive where the virtual machine .vhd file is stored.

• Network to route Double-Take mirroring and replication traffic over—Select the network that you want to use for Double-Take Availability mirroring and replication traffic. If you do not have multiple networks established, you will only be able to select the one network that does exist. If you do not select a network, Double-Take Availability will use DNS to determine a network route to use. Ideally, the networks used for various traffic should be separated. This is dependent on the number of networks that you established when you created the cluster and the priority assigned to each network. For example, if you have two network routes, separate Double-Take Availability and your public traffic. If you have three routes, separate the public traffic and then separate Double-Take Availability from the cluster heartbeat.
• Interval to check unresponsive nodes—Specify how much time, in seconds, between checks of nodes to see if a Double-Take Availability connection can be made.
• Delay connection until resources dependent on this one are online—This option allows you to delay a Double-Take Availability connection until any resources that have the GeoCluster Replicated Disk resource as a dependency are online. By ensuring that all resources that are dependent on the GeoCluster Replicated disk resource are online before starting the connection, the chance of a conflict occurring because application resources are attempting to open files exclusively while Double-Take Availability is mirroring those files is removed.
• Enable orphans—An orphan is a file that exists in the target location but is not in the source location. You can enable the resource to Move orphans or Delete orphans during a mirror. If you choose to move orphan files, specify the location where you want to move them. You should not select the system volume for the orphan files because it could impact the stability of the cluster service.

5. No other settings are required for the GeoCluster Replicated Disk resource, although there are optional settings available. Click OK to save the GeoCluster Replicated Disk configuration changes that you made.
6. If you are using Hyper-V, you have several additional configuration steps.

1. Take the virtual machine’s configuration resource offline by right-clicking on it and selecting Take this resource offline.
2. Modify the virtual machine’s configuration resource and specify the GeoCluster Replicated Disk resource (not the GRD Status resource) as a dependency.
3. Modify the virtual machine resource (the parent of the virtual machine configuration resource) and specify the GeoCluster Replicated Disk resource (not the GRD Status resource) as a dependency.
4. From a command prompt, execute the following command, substituting the name of your GeoCluster Replicated Disk resource.

cluster res "New Geocluster Replicated Disk" /priv sourcefailoverdelay=15

The GeoCluster Replicated Disk will mirror and replicate the virtual machine data to the other cluster nodes.

The GeoCluster Replicated Disk resource will appear offline after it is created. When you bring it online, the following actions occur.

1. A Double-Take Availability replication set is created with the same name that was assigned to the resource.
2. The replication set is connected to all of the possible owners specified in the resource.
3. A mirror is initiated to create the baseline copy of data from the active node to all of the possible owners.
4. The drive where the mirrored data is located on each of the possible owners is made read-only to all other applications except Double-Take Availability.
5. Real-time replication from the active node to all of the possible owners begins.

If you are using Windows 2003, right-click the resource and select Bring online.

If you are using Windows 2008, right-click the resource and select Bring this resource online.

When you take the GeoCluster Replicated Disk resource offline, the following actions occur.

1. Real-time replication from the active node to the possible owners stops.
2. The read-only limitation is removed from the corresponding drive letters on the possible owners.
3. The replication set is disconnected from all of the possible owners.
4. The replication set is deleted.

If you are using Windows 2003, right-click the resource and select Take offline.

If you are using Windows 2008, right-click the resource and select Take this resource offline.

Note:

If the GeoCluster Replicated Disk Resource is offline, data integrity cannot be guaranteed on the other nodes in the cluster.