Guide to Using ROHAN

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ROHAN Academic Computing

Contents

1.0 Introduction

2.0 Connecting to ROHAN

3.0 Finding Help

4.0 Available Software

5.0 Solaris 8 OS

6.0 File Security

7.0 Input/Output

8.0 Email

9.0 Internet

Guide to Using ROHAN

6.0 File Security

6.1 Disk Backup/Mirroring Procedures

New accounts are set up with a private home directory and a umask 077 to create new files and directories as private. It is very important that your home directory not be world writable. If it is, anyone can delete or replace your files. Check with the ls -ld ~command. It displays the mode (permissions) in a form that looks like:


        drwx------
         xxx	        owner
            xxx	        group
               xxx	others
	4   r    read
	2   w    write
	1   x    execute (search for a directory)

There are three sets of letters. The first set applies to the owner of the file, the second to the group of the file, and the third to all others. The letters mean read, write and execute. So mode "-rwxr-x---" means that the owner can do anything; users in his group can read or execute the program, but not change it; and others can't do anything. The letters have values. The previous mode can be expressed as a number "750". The umask bits mask off the permission bits when a file is created. A umask of 077 creates files with mode 700 or "-rwx------".

For additional information on changing file permissions, see 5.2.4 File Protections and 5.2.5 Web Page File Protections.

6.1 Disk Backup/Mirroring Procedures

Only user files in ROHAN's /home and /opt/ftp filesystem are backed up. /home backups are run nightly, while /opt/ftp backups are done monthly. Also they are mirrored on another disk drive (If the orginial drive is damaged, ROHAN switches to the second drive without loss of data).

If you lose files from /home that have been around over a day, they can be recovered from the weekly full backups or the daily incremental backups. Complete a #0560 ROHAN/MORIA File Recovery form (available in LL-200) to have a file restored. Be clear on the full path of the file(s) to be restored. If your account was issued by your professor, you will need to get the form signed by your professor before the restore will be run.

Disk space provided on other filesystems (/tmp, /var/tmp, /var/mail and /scratch) is not backed up at all. However, /var/mail is mirrored like /home, so a disk drive failure is unlikely to cause a loss of mail data.

Short term temporary disk space in /tmp and /var/tmp allows files to remain up to 24 hours. These files are automatically removed after 24 hours each midnight, with no possibility of recovery. Please be aware that the ROHAN system removes all files from /tmp each time it boots.

Longer term temporary storage for faculty and research (including thesis) work is available in the /scratch directory on approval. Approval for this type of storage can be requested via Email to nash@rohan.sdsu.edu. However, if this space becomes full, users will be contacted to remove files. Since this directory is not backed up, files here will be lost in the event of a disk drive failure.

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7.0 Input/Output

7.1 Transferring Files, Tapes and FTP
7.2 Batch Jobs
7.3 Printing

7.1 Transferring Files, Tapes and FTP

Tape to disk file transfers are facilitated when disk space is available. Complete form #0560 ROHAN/MORIA Tape Processing Request, (available in BA-134 and LL-200), and submit it along with your tape(s) in BA-134. Please fill out the form accurately, as small errors may cause your tape job to fail, wasting time and resources. TAR formatted tapes and DAT media tapes are preferable.

FTP (file transfer protocol) file transfers to/from ROHAN are available to users who are on multi-user computers via a TCP Internet connection (such as our Ethernet). On-line HELP is available for FTP via help ftp or, within FTP (FTP>help or FTP>?).

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7.2 Batch Jobs

The batch command allows for running jobs at a low priority. This allows system resources to be optimally utilized and provides better response to interactive users. The batch facility will release up to two jobs at a time as the system load permits. The at command allows for running a command at a later time. For further information on both commands refer to the man pages by entering:

rohan% man batch

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7.3 Printing

7.3.1 Policies
7.3.2 Printing to the Laser Printers
7.3.3 Displaying Print Requests

7.3.1 Policies

User output can be directed to laser printer queues. The following guidelines should be noted and followed when directing output to a laser printer queue:

The paid laser printer queue is called laser. Jobs can be paid for and printed at either the Love Library Student Computing Lab (LL-200) or the BAM X Terminal Lab (BA-110). Laser printing is available at .10 per page (after one hour print requests not authorized and printed are automatically deleted). Note: LL-200 has a DART station to add value to your AztecCard. BA-110 does NOT have a DART station.

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7.3.2 Printing To The Laser Printers

Output may be sent to one of the laser printer queues. The examples queue one copy of file.txt to the chosen laser printer queue awaiting your authorization to print. After one hour, print requests not authorized and printed are automatically deleted.

rohan% lp -d laser file.txt: <--Print to the LL-200 or BA-110 laser printer

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7.3.3 Displaying Print Request

If you don't know your print request id, typing

rohan% lpstat -a

will search all queues and display all requests.

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Neither SDSU nor the State of California nor the California State University system nor any of their employees, makes any warranty or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, or represents that its use would not infringe privately owned rights. Reference to any special commercial products, process, or service by trade name, trademark, manufacturer, or otherwise, does not necessarily constitute or imply its endorsement, recommendation, or favoring by SDSU or the State of California or the California State University system. The views and opinions of the author(s) do not necessarily state or reflect those of SDSU or the State of California or the California State University system and shall not be used for advertising or product endorsement.

This page last modified: March 11, 2003
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SDSU Faculty and Students may send questions about software on ROHAN or ROHAN UNIX problems to problems@rohan.sdsu.edu