VT SGI Usage Overview

This document assumes that you are already familiar with using a UNIX operating system. For a general information about using UNIX systems, see Introduction to Unix;   for specific information regarding SGI ALTIX systems, see SGI Technical Publications.

An SSH (Secure Shell) client is required to log onto the VT ARC Systems. Although you can use the ftp command from a VT ARC system to move files and data to or from the system, it is recommended that you use a secure file copy program, such as as the UNIX "scp" command or a Secure File Transfer Client included with your MS Windows ssh client.

Documentation of many commands is available via the  "info"  command as well as from the  "man" command. For example, to obtain a description of the Intel debugger, enter:

     info  idb

To obtain informaiton about the current hardware installed on the system, enter:

     hinv

Disk Space Allocations

Each user account is initially allocated 5 GB of disk space with more space available upon request.

To view current disk availability, enter:

     df  -k

To view your current disk utilization, enter:

     cd
     du  -k

Disconnected Program Processing

A batch queuing system will be available on "Inferno" in the future, but is not yet installed. In the interim, you can use the  "nohup"  to submit jobs for background processing and enable them to continue processing after logoff, i. e., enter:

     nohup  command_name_and_options  &

where command_name_and_options is the name of a shell script or a command with options that you wish to execute.

For example, to submit the Mathematica program my_prog.ma for background processing, enter:

     nohup  math  <my_prog.ma  &

Note:  it is necessary to press the "Enter" key a second time after the "nohup: appending output to `nohup.out'" message appears in order to regain the command prompt.

For additional information on using the nohup command and general information regarding the use of UNIX systems, see: Background Jobs and Logout -- the "nohup" command

Default File Permissions

When the file system of Inferno was initially installed, the umask was set such that new files are created with user writable and group readable permissions (-rw-r-----), i.e., umask 027. If you desire, you can use the  chmod  command to change the permissions of your existing files or the umask to change the the default permissions which will be assigned to new files. For example, to assign write permission to user and read permission to everyone (-rw-r--r--), add the following command to .profile (Bourne and Korn Shell users) or .login (C Shell users):

     umask  022