To change replication settings

1. Select the Change Replication Settings from the Secondary RVG right-click menu. The Change Replication Settings dialog box appears.

   • To modify each of the basic properties that are listed on this panel, select the required value from the drop-down list for each property.

   
   Complete the information on this panel to specify basic and advanced replication settings for a Secondary as follows:

   Primary side IP	Displays the IP address on the Primary that is to be used for replication. If there is more than one IP address available for replication, you can choose the one that you want to use from the drop-down list. If the required IP address is not displayed in the list then edit the field to add the IP address.
   Secondary Side IP	Displays the IP address on the Secondary that is to be used for replication, if the Secondary is connected to VEA. If there is more than one IP address available for replication, you can choose the one that you want to use from the drop-down list. If the required IP address is not displayed in the list then edit the field to add the IP address.
   Replication Mode	Select the required mode of replication; Synchronous, Asynchronous, or Synchronous Override. The default is synchronous override.
   Replicator Log Protection	The AutoDCM is the default mode for the Replicator Log overflow protection when all the volumes in the Primary RVG have a DCM log. The DCM is enabled when the Replicator Log overflows.
   	The DCM option enables the Replicator Log protection for the Secondary host when the Replicator Log overflows, and the connection between the Primary and Secondary is lost. This option is available only if all the data volumes under the Primary RVG have a DCM Log associated with them.
   	The Off option disables Replicator Log Overflow protection.
   	The Override option enables log protection. If the Secondary node is still connected and the Replicator Log is about to overflow then the writes are stalled until a predetermined amount of space, that is, 5% or 20 MB (whichever is lesser) becomes available in the Replicator Log. If the Secondary becomes inactive due to disconnection or administrative action then Replicator Log protection is disabled, and the Replicator Log will overflow.
   	The Fail option enables log protection. If the log is about to overflow the writes are stalled until a predetermined amount of space, that is, 5% or 20 MB (whichever is lesser) becomes available in the Replicator Log. If the connection between Primary and Secondary RVG is broken, then, any new writes to the Primary RVG are failed.

   Click OK to start replication without any advanced settings.

2. Click Advanced to specify the advanced replication settings.
   

   Complete the Advanced Replication Settings panel as follows or proceed to the next step:

   Latency Protection	By default, latency protection is set to Off and the High Mark Value and the Low Mark Value are disabled. Select the Fail or Override option to enable Latency protection. This Override option behaves like the Off option when the Secondary is disconnected and behaves like the Fail option when the Secondary is connected.
   High Mark Value	This option is enabled only when Latency Protection is set to Override or Fail. It specifies the maximum number of pending updates by which the Secondary can be behind the Primary. The default value is 10000, but you can specify the required limit. To ensure that latency protection is most effective the difference between the high and low mark values must not be very large.
   Low Mark Value	This option is enabled only when Latency Protection is set to Override or Fail. When the updates in the Replicator Log reach the High Mark Value, then the writes to the Primary continue to be stalled until the number of pending updates on the Replicator Log falls back to the Low Mark Value. The default value is 9950, but you can specify the required limit.
   Protocol	UDP/IP is the default replication protocol. Choose TCP/IP or UDP/IP for a regular Secondary. If the storage on the Bunker Secondary is directly accessible from the Primary use the STORAGE protocol, otherwise use TCP/IP or UDP/IP. Note: If the replication protocol for the Bunker Secondary has been set to STORAGE then you can change it only by deleting and recreating the Bunker with the required protocol; UDP/IP or TCP/IP. You cannot change the STORAGE protocol using the Change Replication Settings option.
   Packet Size (Bytes)	Default is 1400. Choose the required packet size from the drop-down list. The default unit for the packet size is Bytes. Some firewalls do not support packet sizes greater than 1400 bytes. If you replicate across such a firewall, then use the default packet size to make sure all the Volume Replicator operations function as required. The minimum packet size that you can specify is 1100 bytes. Note: If you need to set a value for packet size different from that provided in the list then you can do this by using the command line interface.
   Bandwidth	By default, Volume Replicator uses the maximum available bandwidth. To control the bandwidth that Volume Replicator uses for replication, choose Specify Limit from the drop-down list, and then specify the bandwidth limit in the field provided. The default unit is Megabits per second (Mbps) and the minimum allowed value is 1 Mbps.
   Enable Compression	Select this check box to enable compression for the Secondary host.

3. Click OK to change the Replication settings. Click Cancel to cancel the operation.