Patent attributes
A global cylinder group (CG) cache is stored in file server memory and shared by a plurality of file systems supported by the file server. The global CG cache comprises a number CG entries which are pre-allocated in memory. As different file systems are accessed, global CG entries in the CG cache are used to store CG block information for the accesses. With such an arrangement, a file server may support multiple file systems using a single global CG cache without starvation and other the adverse performance impacts of the prior art. According to one aspect of the invention, the global CG cache is periodically scanned to reclaim memory. In contrast to the prior art, where multiple scans were periodically performed of multiple CG caches for memory reclamation, the use of a single CG cache minimizes the impact of CG cache maintenance on file server performance.
