Global UNIX file system cylinder group cache

A file server comprising:

• a global cylinder group (CG) cache, configured to store entries for a plurality of different file systems, the global CG cache being apportioned into a plurality of CG block entries, each cylinder group block entry of the plurality of cylinder group block entries configured to be indexed using a file system identifier and a cylinder group identifier, wherein the file server accesses a plurality of different file systems and wherein at least two of the CG block entries of the global CG cache store CG block information for at least two different file systems;
• and
• a processor in communication with a memory, the processor executing code for:
• receiving file system access requests from a plurality of different file systems, each file system access request including a file system identifier and a cylinder group identifier;
• selecting a CG entry for storing a cylinder block associated with the file system access;
• and
• accessing the CG entry using an index generated in response to the file system identifier and cylinder group identifier.

A non-transitory computer readable storage medium for caching cylinder group header information, the product providing instruction to a computer system for executing the steps of:

• allocating space in a memory to a global cylinder group (CG) cache configured to store entries for a plurality of different file systems, the global CG cache being apportioned into a plurality of cylinder group block entries each cylinder group block entry of the plurality of cylinder group block entries configured to be indexed using a file system identifier and a cylinder group identifier;
• receiving file system access requests from a plurality of different file systems, each file system access request including a file system identifier and a cylinder group identifier;
• selecting a CG entry for storing a cylinder block associated with the file system access;
• and
• accessing the CG entry using an index generated in response to the file system identifier and cylinder group identifier.