Patent ID: 9015525
Filing Date: 2015-04-21
Classification: G06F

Abstract:
1. A multi-controller-server computer system comprising a host server, a peer server, and a high availability direct attached storage system comprising: a first set of directly attached data drives owned by the host server; a second set of directly attached data drives owned by the peer server; a cache memory system comprising a host cache memory residing on or attached to the host server and a peer cache memory residing on or attached to the peer server; wherein the cache memory system provides active-active access to hot I/O data stored in the cache memory system while avoiding multi-initiator conflicts between the first and second sets of directly attached data drives relating to the hot I/O data; wherein the host cache memory is configured to store hot read data resulting from dynamic system usage, based on usage patterns, regardless of ownership of the attached data drives where the hot read data is permanently stored; wherein the peer cache memory is configured to store hot read data resulting from dynamic system usage, based on usage patterns, regardless of ownership of the attached data drives where the hot read data is permanently stored; wherein the hot read data is purged to maintain cache storage capacity; and wherein the host and peer cache memories are further configured to store hot write data mirrored across the host and peer cache memories to prevent data conflicts from arising in dirty write data stored in the host and peer cache memories and to provide uncommitted data availability in case of server or controller failure.