Patent ID: 8565067

Claim:
A non-transitory computer readable storage medium comprising a computer readable program stored on a tangible storage device for link maintenance, wherein the computer readable program when executed on a computer causes the computer to: operate a plurality of first links between data management nodes of clusters, wherein each cluster comprises a tape library, each first link is in an online state, and tasks are communicated between data management nodes over the plurality of first links in the online state; transition the plurality of first links from the online state to a degraded state in response to a connection failure of at least one first link for a remote mount at a first tape library; transition the plurality of first links from the online state to an offline pending state in response to an offline request, wherein the offline pending state completes pending tasks on each first link and forbids new remote mount tasks at the first tape library and new data replication tasks for the first tape library on each first link; transition the plurality of first links from the degraded state to an online pending state in response to a degraded link time interval expiring, wherein the online pending state validates each first link using a digital signature; transition the plurality of first links from the degraded state to the offline pending state in response to the offline request occurring before the degraded link time interval expires; transition the plurality of first links from the offline pending state to an offline state if all pending tasks on the plurality of first links are completed else in response to a force offline command; and transition the plurality of first links from the online pending state to the online state if each first link is validated using the digital signature.