ITS Linux Support
Mounting File Systems Under Linux
Table of Contents
- Mounting ITS File Systems
- Generic Mount Points
- Where to Look for Software
- Where to Turn for Help
A file system can be "mounted" on your Linux system interactively or automatically at startup. Then the file system is just as accessible as any other file system on your computer. The command to "attach" a file or directory is mount, and the command to "detach" a mounted file or directory is umount (see UNIX man (manual) pages for the commands mount and umount for more information). Users should detach from the file system when the resource is no longer needed.
The file named /etc/fstab is used to define mountable file systems and devices on startup. Look there to see what file systems can be mounted, where they may be found locally, who may mount them and with what permissions. If a file or directory is specified in /etc/fstab, it may be mounted at startup. Specifications may also be included for devices that you make available for users to mount, such as /mnt/cdrom and /mnt/floppy. Any entry may be mounted without having to specify the several arguments for the mount command, since those arguments can be taken directly from the /etc/fstab file.
Mounting ITS File Systems
ITS-licensed software, such as Matlab, MAPLE, Mathematica, and IDL are on a server that handles any license restrictions, e.g. the number of simultaneous connections allowed. All are available in the /itc directory that is available from home1.virginia.edu, when it is mounted as described below.
Mount directories under the same names as are used on ITS's server, since commands, from /uva/bin, for example, may have been compiled to look in a particular location for information. In addition, if you follow this guideline, your system's configuration will then match the online documentation written by ITS.
The following examples show how to mount file systems interactively, on a temporary basis. This is the computer from which you ran the network install, and some RPMs are available there.
Before mounting a file system, create directories as mount points, if necessary:
Use this command to interactively mount the /itc filesystem from home1.Virginia.EDU:
/bin/mount home1.virginia.edu:/vol/itc /itc
If you have problems establishing the connection, you may need to stop iptables using
/etc/init.d/iptables stop (to bring up the daemon again, use /etc/init.d/iptables start)
To cause the file systems to be mounted each time the system is started,
the following line must be in your /etc/fstab file:
home1.Virginia.EDU:/vol/itc /itc nfs ro,soft,bg,timeo=3,intr 0 0
The following symbolic links to the mounted directories are also needed:
ln -s /itc/common /common
ln -s /itc/linux /linux
ln -s /linux/uva /uva
ln -s /common/man /man
Generic Mount Points
A logical place to locate mount points is in the directory /mnt. Only the superuser ( or root) can create directories in /mnt. Redhat comes with mount points already set up for a floppy, a CD-ROM, and a parallel port Zip drive. To export a file or directory from a server, item 4 below, it may need to be explicitly specified by root in the /etc/fstab file:
|Node:Mount_dir||Mount Point||File Type||mount Options|
|/dev/fd0||/mnt/floppy||auto||noauto 0 1|
|/dev/cdrom||/mnt/cdrom||iso9660||ro,noauto 0 1|
|/dev/zip||/mnt/zip||vfat||auto,exec 0 1|
Frequently used types:
These are delineated by the -t flag on the mount command.
- auto is for user-mounted media, allowing ext2, ext3, and vfat (Windows)
- iso9660 is used for CD-ROMS and is the default type
- nfs is for files that are mounted over the network
Options used in examples:
These are delineated by the -o flag on the mount command.
- noauto means that the file system is not automatically mounted at boot time, but may be mounted later using mount -a <path>
- auto (as an option) causes a file system to be mounted at boot time
- default options are rw, suid, dev, exec, auto, nouser, and async
- ro allows the file system to be mounted read-only; rw allows read-write
The following are used with the NFS file type.
- bg after an unsuccessful attempt causes subsequent tries to be made in the background
- soft causes an error to be returned if the server does not respond (ITS always uses this)
- timeo sets the NFS time-out period to tenths of a second (default is 0.7 sec)
- intr allows interrupts to be made in programs running over NFS, and the program can then resume where it left off, once the NFS server is back online.
Where to Look for Software
To see what software is available for the Linux platform, browse around in the directories under /itc (mounted from home1.virginia.edu).
Where to begin? Software available on several platforms is likely to be in /common. The structure of the Linux tree makes browsing straightforward; within are subdirectories for uva, contrib, and RPMS.
We make no attempt to have an up-to-date list of the moving target of applications, but a partial list is provided in Linux Applications and Utilities from ITS.
Where to Turn for Help
For immediate questions, please call the UVa Help Desk at 4-HELP (434-924-4357).
Use the Search facility at the top of any ITSWeb page, typing in keywords such as "linux", "math", "abaqus", "error", and the like to narrow your search. Links may take you to local documentation with Readme or Example files on the particular application.
If your question is beyond the scope of this document, contact the UVa Help Desk. ITS's Linux support is limited, and you are expected to be able to handle System Administration if you are going to have a Linux box on the UVa network. We recommend that you look on the Web for answers to general questions. Try one of the following:
Page Updated: 2012-02-16