What protocols are used in NAS?
There are several network protocols used to access data on a Network Attached Storage device. They are:
NFS (Network File System):
- Originally developed by Sun and released in 1985
- Provides remote file system with access semantics across a network (local or wide)
- File system is mounted for accessing by client
- Open standard for file sharing
- Two versions in popular usage (v2 and v3)
CIFS (Common Internet File System):
- Developed by Microsoft as a remote file system access protocol for use over the Internet
- File sharing support with file locking mechanisms
- Derived from Microsoft SMB in 1992
- Remote file systems don?t have to be mounted but can be referred to by globally significant names
- Supports Unicode file naming
- Implemented on some Unix, Linux, and VMS usually via SAMBA
- Locking is implemented as "Opportunistic Locks" to allow local buffering and exclusive access (hard locks)
NCP (Netware Communication Protocol):
- This is the Novell Netware file serving protocol that competes with NFS and CIFS.
- This is the Apple file serving protocol that competes with NFS and CIFS.
FTP (File Transfer Protocol):
- This is a file transfer protocol between computers where file data is transferred with appropriate handshaking.
HTTP - Hyper Text Transport Protocol
- This is the method of accessing data over the web typically for display of information in web pages.
Not all NAS devices support all of these protocols. The specifications of the NAS device should be examined to see if the protocol you require is supported. There are some variations in implementation as well, especially in the file locking area.
Evaluator Group, Inc.
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This was first published in October 2001