Please Whitelist This Site?

I know everyone hates ads. But please understand that I am providing premium content for free that takes hundreds of hours of time to research and write. I don't want to go to a pay-only model like some sites, but when more and more people block ads, I end up working for free. And I have a family to support, just like you. :)

If you like The TCP/IP Guide, please consider the download version. It's priced very economically and you can read all of it in a convenient format without ads.

If you want to use this site for free, I'd be grateful if you could add the site to the whitelist for Adblock. To do so, just open the Adblock menu and select "Disable on tcpipguide.com". Or go to the Tools menu and select "Adblock Plus Preferences...". Then click "Add Filter..." at the bottom, and add this string: "@@||tcpipguide.com^$document". Then just click OK.

Thanks for your understanding!

Sincerely, Charles Kozierok
Author and Publisher, The TCP/IP Guide


NOTE: Using software to mass-download the site degrades the server and is prohibited.
If you want to read The TCP/IP Guide offline, please consider licensing it. Thank you.

The Book is Here... and Now On Sale!

Read offline with no ads or diagram watermarks!
The TCP/IP Guide

Custom Search







Table Of Contents  The TCP/IP Guide
 9  TCP/IP Application Layer Protocols, Services and Applications (OSI Layers 5, 6 and 7)
      9  Network File and Resource Sharing Protocols and the TCP/IP Network File System (NFS)
           9  TCP/IP Network File System (NFS)

Previous Topic/Section
NFS Server Procedures and Operations
Previous Page
Pages in Current Topic/Section
1
2
3
Next Page
TCP/IP Network Configuration and Management Protocols (BOOTP, DHCP, SNMP and RMON)
Next Topic/Section

NFS File System Model and the Mount Protocol
(Page 2 of 3)

The Mount Protocol

Before NFS can be used to allow a client to access a file on a remote server, the client must be given a way of accessing the file. This means that a portion of the remote file system must be made available to the client, and the file opened for access. A specific decision was made when NFS was created to not put file access, opening and closing functions into NFS proper. Instead, a separate protocol was created to work with NFS, so that if in the future the method of providing file access needed to be changed, it wouldn't require changes to NFS itself. This separate mechanism is called the Mount Protocol, and is described in Appendix A of RFC 1094 (NFSv2). Note that while functionally distinct, Mount is considered part of the overall NFS package.

When NFS was revised to version 3, the Mount Protocol was similarly modified. The NFSv3 version of the Mount Protocol is defined in Appendix I of RFC 1813 (NFSv3). It contains some changes to how the protocol works, but the overall operation of the two versions of Mount is pretty much the same.

The term “mount” is actually an analog to a hardware term that refers to making a physical storage volume available. In the “olden dayse” storage devices were usually removable disk packs, and to use one you mounted it onto a drive unit. In a similar manner, NFS resources are logically mounted using the Mount protocol, which makes the shared file system available to the client. A file can then be opened and a file handle returned to the NFS client so it can reference the file for operations such as reading and writing.

Key Concept: Versions 2 and 3 of NFS do not include procedures for opening or closing resources on a remote server. Before NFS tasks can be accomplished on these versions, the special Mount protocol must be employed to mount a filesystem and create a file handle to access a file on it; the protocol is also used to unmount the file system when no longer required. The Mount protocol is implemented in a manner very similar to NFS itself, defining procedures that use RPC and XDR. In version 4 of NFS, Mount is no longer needed; the tasks it performs are implemented as NFSv4 operations.



Previous Topic/Section
NFS Server Procedures and Operations
Previous Page
Pages in Current Topic/Section
1
2
3
Next Page
TCP/IP Network Configuration and Management Protocols (BOOTP, DHCP, SNMP and RMON)
Next Topic/Section

If you find The TCP/IP Guide useful, please consider making a small Paypal donation to help the site, using one of the buttons below. You can also donate a custom amount using the far right button (not less than $1 please, or PayPal gets most/all of your money!) In lieu of a larger donation, you may wish to consider purchasing a download license of The TCP/IP Guide. Thanks for your support!
Donate $2
Donate $5
Donate $10
Donate $20
Donate $30
Donate: $



Home - Table Of Contents - Contact Us

The TCP/IP Guide (http://www.TCPIPGuide.com)
Version 3.0 - Version Date: September 20, 2005

© Copyright 2001-2005 Charles M. Kozierok. All Rights Reserved.
Not responsible for any loss resulting from the use of this site.