The information stored on the device server is in cache directories and includes a local copy of the Infrastructure Database and cache data from device pulls. This information does not need to be backed-up and is not required in the event of a server crash.
In the event of a device server crashing, it needs to be built with the same IP address and hostname as the original Device Server. The new device server will then download the identity of the lost/corrupted device server from the Application Servers and assume its device management tasks.