Patent ID: 6161192
Filing Date: 2000-12-12
Classification: G06F,G11B

Abstract:
A method for formatting a RAID array of storage devices with device metadata for data blocks on each storage device and with RAIDset metadata for RAIDed blocks in the RAID array, the RAIDed blocks include data blocks and parity blocks and are RAID protected by being distributed across the RAID array of storage devices, said method comprising the steps of:(A) writing as device metadata a device FE bit on each storage device for each RAIDed block on the storage device so that there is a one-to-one correspondence between each RAIDed block on the storage device and a device FE bit, said device FE bit indicating whether or not a corresponding RAIDed block is consistent and thereby indicating useability of the corresponding RAIDed block to reconstruct lost data in another RAIDed block; and(B) writing as RAIDset metadata a RAIDset FE bit for each RAIDed user data block in the RAID array so that there is a one-to-one correspondence between each RAIDed user data block in the RAID array and a RAIDset FE bit, said RAIDset FE bit indicating whether or not a corresponding RAIDed user data block contains true data.