一， CephFS 与nfs-ganesh 框架
nfs-ganesha模块化的体系结构，实现复杂，维护简单：
● RPC layer:
– uses libntirpc
● Filesystem Abstraction layer (FSAL)
– Provides API for exported namespace
● Metadata cache (MDCACHE)
– Chunked dirent cache (version 2.6)
● Dbus Interface
– System management and communication
● Log Management– Support for internal logging