Patent ID: 7536588
Filing Date: 2009-05-19
Classification: G06F

Abstract:
1. A method of servicing storage devices in a storage subsystem, said storage subsystem including a plurality of removable trays, each of said trays with a plurality of functional storage devices, the method comprising: initially designating as temporarily removed, one or more functional storage devices in a tray of the storage subsystem; upon removal of the tray from the storage subsystem, logging at least some writes to the one or more functional storage devices in the tray to a log maintained at another one of said storage devices in said storage subsystem; notifying, responsive to a configurable threshold, a user or a service representative that said log may overflow unless the tray is reinserted within a specific duration; said specific duration calculated using a number of entries in said log and a rate of write operations to said one or more functional storage devices; deciding, responsive to overflow of said log due to said write operations if said removal was temporary or was a reinsertion; said reinsertion requiring a rebuilding of data; managing reads to the functional storage devices through reconstruction from at least some active storage devices in the storage subsystem that are not removed from the storage subsystem; upon reinsertion of the tray in the storage subsystem, verifying an identity of the tray by checking one or more of a serial number, a controller identification, a slot, a physical identification and a timestamp of a start of removal operation; if said verifying fails, then notifying said user or said service representative; and resynchronizing the functional storage devices in the tray to ensure data consistency.