Directory snapshots based on directory level inode virtualization

A method comprising:

• snapshotting, by a system comprising a processor, a first directory that is within a filesystem root directory namespace, the first directory associated with a first directory inode mapping file comprising a first directory virtual inode number associated with a directory real inode data structure, the snapshotting comprising allocating a second directory inode mapping file, and copying data of the first directory inode mapping file to the second directory inode mapping file;
• detecting, by the system, a requested modification to the first directory;
• and
• in response to the detecting the requested modification, splitting, by the system, the directory real inode data structure into a first directory real inode data structure and a second directory real inode data structure, assigning a new directory real inode number to the first directory real inode data structure, and updating the first directory inode mapping file with the new directory real inode number.

A non-transitory machine-readable medium, comprising executable instructions that, when executed by a processor, facilitate performance of operations, the operations comprising:

• maintaining a first directory inode mapping file associated with a first directory that is within a filesystem root directory namespace, the first directory inode mapping file comprising a first directory virtual inode number associated with a first directory real inode number of a directory real inode data structure;
• creating a second directory comprising a snapshot of the first directory, the creating comprising allocating a second directory inode mapping file for the second directory, and copying data of the first directory inode mapping file to the second directory inode mapping file;
• detecting a requested modification to the first directory;
• and
• in response to the detecting the requested modification:
• splitting the directory real inode data structure into a first directory real inode data structure for the first directory and a second directory real inode data structure for the second directory, the splitting comprising:
• allocating the first directory real inode data structure,
• assigning a new directory real inode number to the first directory real inode data structure, and
• updating the first directory inode mapping file with the new directory real inode number.