NFS Part II, Usage

Ron McCarty

In Part I (Sys Admin, October 2001, http://www.sysadminmag.com/articles/2001/0110/0110h/0110h.htm), I covered NFS at a high level. This month I will cover the NFS protocol and daemons in more detail, including examples using Linux Red Hat 6.2 and Solaris 2.6.

NFS Penguin Style

Although the Linux coverage here is based upon Red Hat 6.2, the kernel version is 2.4.9. Red Hat 6.2 shipped with version 0.1.6 of the nfs-utils package, but the system was also upgraded to nfs-utils version 0.3.1, the latest available at the time the column was written. Version 0.3.1 is available at:

http://sourceforge.net/project/shownotes.php?group_id=14&release_id=24211

The nfs-utils contains the NFS executables exportfs, lockd, mountd, nfsd, nfsstat, nhfsstone, rquotad, showmount, and statd.

Unfortunately for Linux administrators, the NFS support has at times been downright confusing as support for particular features and versions have been added with different kernel and nfs-utils packages. Thankfully, things are getting better for Linux administrators. Current distributions include the latest kernel support and nfs-utils. For older production systems, the NFS-HOWTO section 2.4 documents exactly what is available with each combination, and the nfs-utils authors are keeping the package backward compatible with earlier versions but providing “...lots of security and bug fixes.”

NFS support must be activated when the kernel is compiled. Additionally, NFS version 3 support must also be added to the kernel if it’s needed.

For distributions supporting linuxconf, NFS services for both servers and clients are easily configured. Although linuxconf gives a quick way to set up NFS, what files are being created or edited are much more important for the administrator to understand when trouble arises and the NFS configuration needs to be analyzed.