System and method for recovering a segment directory for a log structured array
 In a storage system comprising an array of storage devices including a processor and memory, a plurality of data blocks are organized on the storage devices in segments striped across the storage devices. A main directory, stored in memory, contains the location on the storage device of each of the data blocks. For each segment a segment directory having information on the data blocks in the segment is stored on the storage devices. When a damaged segment directory is detected, a checkpoint of the main directory is written to the storage devices. A list is maintained of damaged segment directories such that segments on the damaged segment directories list are not garbage collected. Following a main directory recovery procedure, the damaged segment directories are reconstructed using the main directory. 
International Business Machines Corporation
G
G06F
inventional
Juan Hai-Fang Dung K. Mien
Li Yun Nguyen Shih