Configuring Server Groups for Replication

In this topic:

Partnering with a remote server group for replication

Enabling/disabling data compression during data transfer

Assigning IP addresses for data transfers

Changing network ID and credentials

Changing the IP address for communications

Removing a replication group

Partnering with a Remote Server for Replication

Two server groups can be "partnered" to asynchronously mirror virtual disks (replication) between local and remote server groups.

To replicate a virtual disk from a local server group to a remote server group, the remote group is added as a replication partner to the local group. One local group can also be partnered with multiple remote groups. Additional Replication Site licenses are required on the local group in order to configure multiple remote groups.

(When replicating within the same server group these steps are not necessary, simply create the replication.)

  • The servers must be connected to each other over a WAN or LAN. TCP/IP connections are required. Use Internet Protocol Version 4 (IPv4). (IPv6 is not currently supported for iSCSI targets on DataCore Servers.)
  • Local and remote server groups must be running the same SANsymphony software version.
  • DataCore Servers (including Replication partners) and management consoles require functioning name resolution to resolve computer names to IP addresses. To ensure proper communication and data transfer, all servers running SANsymphony software in the local and remote server groups involved in virtual disk replication must be able to resolve the host names of all other DataCore Servers in those groups. If using hosts files, the name in the file must be identical to the actual computer name, including case. See Name Resolution for details.

    DataCore recommends using host names instead of IP addresses. IP addresses can be determined from host names regardless of changes to the IP addresses.

  • When adding the remote group, the same user name and password for the logon account must be registered for the local and remote groups in order to establish bidirectional communications. (The user name that is registered in SANsymphony software must be identical to the Windows account created for the user.) Verify that the user credentials are registered in the SANsymphony Management Console in the remote group.
  • DataCore recommends creating a dedicated local administrator account with password for both server groups to use when creating replications.
  • The best practice when replicating between sites is to use a dedicated network card for replication. Sharing the network card for various other uses, such as iSCSI or LAN management, may impact performance.

To partner with a replication group:

  1. Ensure both server groups have unique server group names, rename the server groups if necessary.
  2. In the DataCore Servers Panel, right-click on the local group and select Partner with Replication Group.
  3. In the Partner with Replication Group page, enter the name or IP address of any DataCore Server belonging to the remote group. (This name/address will be used for communications, not necessarily data transfers.)

    If possible, DataCore recommends using host names instead of IP addresses. IP addresses can be determined from host names regardless of changes to the IP addresses.

  4. Enter credentials:
    1. In the Remote Server Group Credentials area, enter the user account name and password for the remote logon account.
    2. In the Local Server Group Credentials area, enter the user account name and password for the local logon account.
  5. Click Partner.

After the replication group is added:

  • The remote replication group is added to the DataCore Servers Panel on local servers, and the local group is added to the DataCore Servers Panel on servers belonging to the remote replication group.
  • A Replication Group Details page is created. Click on the replication group in DataCore Servers Panel to open the details page.

Data Compression

Data compression is used to speed up data transfers by lowering the amount of data transmitted over the network.

Data compression is enabled for remote replication groups by default. By default, data is not compressed for local replications.

If replication data is already compressed in some other manner on the replication (destination) server, such as through a hardware VPN device with native compression, then replication data compression is not required and can be disabled.

To enable or disable data compression:

  1. In the DataCore Servers Panel, click on the replication group to open the Replication Group Details page.
  2. In Parametersarea, select or clear the Use data compression when replicating to this group check box.
  3. Click Apply.

Assigning the IP Address for Data Transfers

The partner replication IP address to use for data transfers to the replication destination can be selected.

To select the address for data transfers:

  1. In the DataCore Servers Panel, expand the replication group.
  2. Click on the server in the replication group to open the Partner Server Details page.
  3. In the drop-down list for replication transfer, select the IP address to use on the partner replication server. This will establish the path to use between the source and destination replication servers.

    The Default selection will use the replication server host name; therefore, the default IP address that is resolved from DNS name resolution will be used.

  4. Click Apply.

Changing Network ID and Credentials

When a replication group is partnered with the local server group, the network ID was required and credentials were optional for the purpose of remotely replicating virtual disks. This information can be changed if necessary. The partner server can be online or offline when the information is updated.

To update replication group information:

  1. In the DataCore Servers Panel, click the replication group to open the Replication Group Details page.
  2. In the Replication Group Details page, enter the updated information and click Apply.

Changing the IP Address for Communications

The server name or IP address used for communication between replication groups can be changed.

To change:

  1. In the DataCore Servers Panel, click the replication server group to open the Replication Group Details page.
  2. In the box labeled Remote server name or IP address, enter the new name or IP address.

    DataCore strongly recommends using hostnames instead of IP addresses. IP addresses can be determined regardless of changes to the IP addresses.

  3. Click Apply.

Removing a Replication Group

To remove a replication group, the replication group cannot be involved in virtual disk replications.

To remove a replication group:

  1. Split any replications that involve the replication group.

    The Split command can be initiated from the context menu in the panels or any virtual disk list.

  2. In the DataCore Servers Panel, right-click on the remote replication group and select Remove Replication Group.
  3. Click Yes in the confirmation message to continue.