Networked File Access
Paralleling the discussion of local disk accesses, this section looks at networked access. Accessing a file over a network is hundreds of times slower than reading a cached copy from memory. Many types of cache exist to speed up file accesses. Changing your workload to make it more “cache friendly” can result in very significant performance benefits.
NFS Access Caching
Again, we’ll start by looking at the simplest configuration, the open, fstat, read, write, and mmap operations on an NFS-mounted file system, as shown in Figure 12-3.
Figure 12-3. File Access Caches for NFS and Cachefs
Compared with the previous diagram ...