Optimized metadata prediction

A system, comprising:

• a memory;
• and
• at least one processor that is operatively coupled to the memory, the at least one processor being configured to perform the operations of:
• receiving a write request;
• identifying a sector that corresponds to the write request, the sector being a unit of storage in a permanent storage, the sector including a plurality of blocks;
• detecting whether a true copy of a sector signature corresponding to the write request is stored in a cache, wherein the sector signature includes plurality of block-specific portions, each block-specific portion corresponding to a different one of the plurality of blocks, each block-specific portion being a counter that is incremented every time data is written to the block-specific portion's corresponding block;
• when the true copy of the sector signature is stored in the cache, acknowledging the write request and subsequently completing the write request;
• when the true copy of the sector signature is not stored in the cache, generating a predicted copy of the sector signature based on a plurality of sector signatures that have been stored in the cache during a predetermined period, acknowledging the write request after the predicted copy of the sector signature is generated, retrieving the true copy of the sector signature from the permanent storage, reconciling the predicted copy of the sector signature with the retrieved true copy of the sector signature, the reconciling being performed to after the write request is acknowledged, and completing the write request after the predicted copy of the sector signature is reconciled with the true copy of the sector signature.

A method for use in a storage system, comprising:

• receiving a write request;
• detecting that a true copy of metadata corresponding to the write request is not stored in a cache;
• when the true copy of the metadata is not stored in the cache, generating a predicted copy of the metadata, retrieving the true copy of the metadata from a permanent storage, reconciling the predicted copy of the metadata with the retrieved true copy of the metadata, the reconciling being performed to after the write request is acknowledged, and completing the write request after the predicted copy of the metadata is reconciled with the true copy of the metadata,
• wherein the reconciling is performed concurrently with the write request being aged out in an aging queue.