Abstract: A method and apparatus for logging write requests to a storage volume in a network data switch is described. In one example, a switch component in a switch receives a write request from a host server. The write request is associated with a destination in the storage volume. A logging element is identified that is associated with the destination of the write request. The logging element may be a switch component in the switch (e.g., a virtualization card), or may be dedicated logging circuitry in the switch. The identified logging element then logs a write intent for the destination in a log.

Abstract: System and method for distributing volume status information in a storage system. According to one embodiment, a system may include a plurality of volumes configured to store data, where the volumes are configured as mirrors of one another, and a plurality of hosts configured to access the plurality of volumes. A first one of the plurality of hosts may be configured to execute a mirror recovery process and to maintain a progress indication of the mirror recovery process, and the first host may be further configured to distribute the progress indication to another one or more of the plurality of hosts.

Abstract: Systems, methods, apparatus and software can configure, support, and make use of a coordinator virtual device to determine which node or nodes of a cluster should be ejected from the cluster as a result of a cluster partition or other error event. Fencing software operating on the cluster nodes monitors the cluster for a cluster partition (split-brain) event, and when such an event occurs, software on the nodes attempts to gain control of the coordinator virtual device. A node that succeeds in gaining control of the coordinator virtual device survives. Nodes failing to gain control of the coordinator virtual device remove themselves or are removed from the cluster. The coordinator virtual device can be established by a virtual device configuration server which provides coordinator virtual device access to cluster nodes acting as virtual device configuration clients.