DataKeeper Volume Resource Health Check

A DataKeeper Volume resource provides two functions that are used by the Microsoft Cluster service to check for availability and health of the DataKeeper Volume resource. A simple check LooksAlive and a more rigorous check IsAlive.

LooksAlive

The Cluster service calls the LooksAlive function based on the specified interval. The default is every 20 seconds on a freshly installed system, or 60 seconds after upgrading DataKeeper Cluster Edition from a version prior to 8.4.0. The LooksAlive function performs a quick check of the volume device. When the LooksAlive test fails, the cluster service will call the IsAlive test immediately.

IsAlive

Performs a thorough check to determine if the specified resource is online (available for use). The default is 120 seconds on a freshly installed system, or 300 seconds after upgrading DataKeeper Cluster Edition from a version prior to 8.4.0. If the device for the mirror becomes unreachable by DataKeeper, the IsAlive check will detect this condition and will mark the resource as Failed.