Apparatus, system, and method for persistent data management on a non-volatile storage media

Abstract

Data is stored on a non-volatile storage media in a sequential, log-based format. The formatted data defines an ordered sequence of storage operations performed on the non-volatile storage media. A virtual storage layer maintains volatile metadata, which may include a forward index associating logical identifiers with respective physical storage units on the non-volatile storage media. The volatile metadata may be reconstructed from the ordered sequence of storage operations. Persistent notes may be used to maintain consistency between the volatile metadata and the contents of the non-volatile storage media. Persistent notes may identify data that does not need to be retained on the non-volatile storage media and/or is no longer valid.

1 - 17 . (canceled) 
     
     
         18 . A method for managing data stored on non-volatile storage media, wherein data is stored on the non-volatile storage media in a sequential, log-based format comprising an ordered sequence of storage operations performed on the non-volatile storage media, and wherein data is appended to a storage division exclusively at a head of the ordered sequence, the method comprising:
 receiving a TRIM message from a storage client, the storage client configured to send the TRIM message in response to determining that a logical identifier no longer needs to reference data stored on a non-volatile storage media;   storing a persistent note on the non-volatile storage media to indicate that data of the logical identifier does not need to be preserved on the non-volatile storage media; and   in response to recovering a storage division comprising the persistent note,
 appending the persistent note to a head of the ordered sequence of storage operations with an indication of an original position of the persistent note in the ordered sequence of storage operations in response to the original position having a position later than a tail of the ordered sequence of storage operations, and 
 removing the persistent note from the non-volatile storage media in response to the original position having a position in the ordered sequence earlier than the tail of the ordered sequence of storage operations. 
   
     
     
         19 - 25 . (canceled) 
     
     
         26 . The method of  claim 18 , further comprising acknowledging the TRIM message in response to storing the persistent note on the non-volatile storage media. 
     
     
         27 . The method of  claim 18 , further comprising logically invalidating the logical identifier. 
     
     
         28 . The method of  claim 27 , wherein logically invalidating the logical identifier comprises updating volatile metadata. 
     
     
         29 . The method of  claim 28 , wherein the volatile metadata comprises one or more of a forward index, a reverse index, a validity bitmap, and a discardability index. 
     
     
         30 . The method of  claim 27 , wherein logically invalidating the logical identifier comprises invalidating a storage unit of the non-volatile storage media associated with the logical identifier. 
     
     
         31 . The method of  claim 18 , further comprising storing the persistent note in response to evicting data of the logical identifier from a cache. 
     
     
         32 . The method of  claim 18 , further comprising returning an indication that data of the logical identifier does not exist on the non-volatile storage media in response to a query for data of the logical identifier. 
     
     
         33 . The method of  claim 18 , wherein the TRIM message comprises a directive that data of the logical identifier is not to be retained on the non-volatile storage media, the method further comprising returning an indication that data of the logical identifier does not exist in response to a read request for data of the logical identifier. 
     
     
         34 . The method of  claim 18 , further comprising moving the persistent note from a first storage division to a second storage division on the non-volatile storage media, wherein moving the persistent note comprises consolidating the persistent note into a summary persistent note comprising two or more persistent notes. 
     
     
         35 . The method of  claim 18  further comprising removing the persistent note from the non-volatile storage media in response to removing data of the logical identifier from the non-volatile storage media. 
     
     
         36 . The method of  claim 18 , further comprising removing the persistent note from the non-volatile storage media in response to storing data of the logical identifier subsequent to storing the persistent note. 
     
     
         37 . The method of  claim 18 , wherein the persistent note is appended together with an indicator of an original position of the persistent note in the ordered sequence of storage operations. 
     
     
         38 . The method of  claim 37 , wherein the original position of the persistent note differs from a position in the ordered sequence of a storage division to which the persistent note is appended.