Replacing the Edge
In the event of catastrophic failure, you might need to replace the Edge appliance and remap the LUNs. It is usually impossible to properly shut down an Edge LUN and bring it offline because the Edge wants to commit all its pending writes (for the LUN) to the Core. If the Edge has failed, and you cannot successfully bring the LUN offline, you need to manually remove the LUN.
The blockstore is a part of Edge, and if you replace the Edge, the cached data on the failed blockstore is discarded. To protect the Edge against a single point of failure, consider an HA deployment of Edge.
Use the following procedure for an Edge disaster recovery scenario in which there is an unexpected Edge or remote site failure. This procedure does not include Edge HA.
We recommend that you contact Riverbed Support before performing the following procedure.
1. Schedule time that is convenient to be offline (if possible).
2. On the Core, force unmap LUNs from the failed Edge.
3. In the Core Management Console, remove the failed Edge.
4. Add replacement Edge. You can use the same Edge Identifier.
5. Map LUNs back to the Edge.
When the LUNs are remapped to the replacement Edge, the iSCSI LUN IDs might change. You must rescan or rediscover the LUNs on the ESXi.
You can lose data on the LUNs when writes to the Edge are not committed to the Core. In the case of minimal data loss, it is possible that you can easily recover the LUNs from a crash consistent state, such as with a filesystem check. However, this ease of recovery depends on the type of applications that were using the LUNs. If you have concerns about the data consistency, we recommend that you roll back the LUN to a latest application-consistent snapshot.