Improving Storage System Performance By Making the File System Aware of Background Activities on the Storage controller
Original Publication Date: 2003-Feb-19
Included in the Prior Art Database: 2003-Feb-19
Today's storage control units often perform background activities (e.g., background copy for a point-in-time copy) which lead to temporary increased load on certain ranks(sometimes called RAID arrays). If the storage applications (e.g., SAN File systems) sitting on top of these control units were aware of this background activity, they could potentially redirect some of their requests to other ranks, thus improving overall system performance. In this invention, the storage controller notifies the storage application that some portion of the data, e.g., a RAID rank, it controls will deliver degraded performance. This information can be provided via an SNMP alert or other communication mechanism. The storage application then attempts to direct its activities away from this portion of the data. Several concrete means of doing this include: 1) allocating new storage from different portions of the storage controlled by this controller 2) using a mirroring approach, to direct the I/O to different portions of the storage 3) closing data base logs stored on the portion of the storage with degraded performance and opening new logs on different portions of the storage Other means exists.