摘要 |
A method and a storage system are provided for implementing indirection tables for persistent media or disk drives with enhanced emergency power outage (EPO) protection for the indirection data, such as shingled perpendicular magnetic recording (SMR) indirection tables. Chaining of indirection data is provided with one block pointing to another block of the indirection data stored to disk or flash memory. An EPO-safe buffer is used to store a metadata entry responsive to completing each host write command. Each metadata entry is added to a metadata block, a pointer is stored in the EPO-safe buffer to a current metadata block and a previous metadata block. For a next EPO-safe buffer update entries are removed for the previous metadata block, keeping the last two metadata pointers and last metadata block.
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