Hierarchical file block variant tracking for performance in parallelism at multi-disk arrays

A computer-implemented method of operation for at least one processor to operate as a versioned file block location tracker (tracker) apparatus for intermediation between a plurality of librarian circuits and a remote file server, the method comprising:

• receiving, from a processor core via a local network interface, a plurality of file block commit request indicia into a non-transitory media for various file extents of a version controlled file;
• storing said plurality of file extents into a local non-transitory store coupled to the file block write/acknowledgement circuit;
• transmitting an acknowledge indicia for a file commit to a sender of file block commit request, by means of a file block write/acknowledgement circuit coupled to the local network interface;
• incrementing a number of unfulfilled file block commit requests of file block commit request indicia yet unfulfilled for the version controlled file;
• upon exceeding a threshold of parallelism of a count of unfulfilled file block commit requests, triggering a file write operation, according to ranks of parallelizable execution and regardless of order of reception into the non-transitory media store, for all stored file extents of the version controlled file into a remote multi-disk non-transitory media;
• and
• reinitializing the count of the number of unfulfilled file block commit request indicia, whereby throughput of virtual machines attached to the librarian circuits is improved by releasing a resource for reuse as soon as a write acknowledgement is received by the librarian, wherein the threshold of parallelism is a function of a number of parallel disk head actuators in a multi-disk array (Dna), wherein a function [f(Dna)] of the number of parallel disk head actuators in the multi-disk array is an integer multiple of an integer of a logarithm of the number of parallel disk head actuators [n*Integer(log Dna)], and
• whereby data at a primary (R1) volume are synchronized with data at a secondary (R2) volume.