Managing a cache in a multi-node virtual tape controller

摘要

According to one embodiment, a system includes a virtual tape library having a cache, a virtual tape controller (VTC) coupled to the virtual tape library, and an interface for coupling multiple hosts to the VTC. The cache is shared by the multiple hosts, and a common view of a cache state, a virtual library state, and a number of write requests pending is provided to the hosts by the VTC. In another embodiment, a method includes receiving data from at least one host using a VTC, storing data received from all the hosts to a cache using the VTC, sending an alert to all the hosts when free space is low and entering into a warning state, sending another alert to all the hosts when free space is critically low and entering into a critical state while allowing previously mounted virtual drives to continue normally.

主权项

1. A system, comprising:
a virtual tape library having a cache; at least one virtual tape controller coupled to the virtual tape library; and an interface for coupling at least two hosts to the at least one virtual tape controller, wherein the cache is shared by the at least two hosts, and wherein a common view of a cache state, a virtual library state, and a number of write requests pending is provided to the at least two hosts by the virtual tape controller, wherein the at least one virtual tape controller is configured to monitor a cache free space size at least once every ten seconds when in a warning state.