What really are LooksAlive and IsAlive?

LooksAlive: Will perform a cursory status check every  five seconds (by default). This routine checks that the resource is not marked as “Failed,” which indicates a loss of the resource.

IsAlive: This is a much more complete check that occurs every 60 seconds (by default). This routine checks that the resource status is not marked as “Failed,” which indicates the resource failure. If the status is not marked as “Failed,” in the case of a Physical Disk resource a FindFirstFile runs on the root of the disk to make sure the file system is still mounted and that the disk is accessible.


Some resources are programmed to use both, some just LooksAlive. Ask your application vendor when troubleshooting Alive resources.

One thought on “What really are LooksAlive and IsAlive?

  1. with Failover clustering, our physicsl disk going to failed state for every isAlive() where we are copying and deleting some files. when we don’t perform any deletion then the disk resource maintains online state. Could you write more details about what is happening inside isAlive() w.r.t physical disk resource.
    Thanks a bunch

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