datastore sync enable

Enables pairs of SteelHeads on the same side of a WAN to automatically keep their data stores synchronized. This feature is also known as active‑active synchronization.

This feature provides for failover and overflow capacity without performance loss. Beginning with RiOS 4.0, you can enable this feature independent of whether or not you have enabled failover.

For deployments requiring the highest levels of redundancy and performance, RiOS supports warm standby between designated master and backup devices. Using automated data store synchronization, the data segments and the references created via data streamlining are automatically copied from the master to the backup appliance. In the event of a failure in the master appliance, the backup appliance takes its place with a warm data store, and can begin delivering fully-optimized performance immediately. Warm data transfers send only new or modified data, dramatically increasing the rate of data transfer over the WAN.

RiOS supports active-active configurations, in which each appliance is serving both as a master for some traffic and as a backup for the other appliance, with full data store synchronization. Automatic synchronization can include appliances in a serial or WCCP cluster, and appliances using connection forwarding.

Synchronization takes place over the primary or auxiliary port only.

Failover is not required for data store synchronization. Although the failover and synchronization features are typically enabled together, you can enable data store synchronization independently of standard failover.

In most implementations in which both failover and synchronization are enabled, the same SteelHead serves as the master for both failover and data store synchronization. However, if you enable failover and synchronization, the failover master and the synchronization master do not have to be the same SteelHead.

You configure two SteelHeads to enable synchronization, one as a server (the synchronization master) and the other as a backup. The synchronization master and its backup:

• do not have to be in the same physical location. If they are in different physical locations, they must be connected via a fast, reliable LAN connection with minimal latency.

When you have configured the master and backup appliances, you must restart the SteelHead service on the backup SteelHead. The master restarts automatically.

After you have enabled and configured synchronization, the data stores are actively kept synchronized. For details on how synchronized appliances replicate data and how data store synchronization is commonly used in high availability designs, see the SteelHead Deployment Guide.

If one of the synchronized SteelHeads is under high load, some data might not be copied. For detailed information, see the SteelHead Deployment Guide.

If data store synchronization is interrupted for any reason (such as a network interruption or if one of the SteelHeads is taken out of service), the SteelHeads continue other operations without disruption. When the interruption is resolved, data store synchronization resumes without risk of data corruption.