Documentation
Computer Support
 |
Frequently Asked Questions |
Frequently Asked Questions (FAQ)
- How do I get help?
- How do I get an Account? For a visitor?
- How do I login? What are my options?
- How do I logout? How often should I logout?
- What can I do about SPAM and how can I protect myself from suspicous/malevolent emails
- How do I reboot? Should I reboot?
- What is backed up and how often? How do I restore a file?
- How much disk space can I use?
- How do I print from Linux?
- How I setup a personal/class webpage? How do I change information on my Departmental Webpage?
- Where are the public printers?
- What classrooms have computers and how do I use them?
- Do we have a scanner and how do I use it?
- How do I use a Floppy (or CDROM) under Unix
- Where should I run large computational jobs? Do we have a cluster?
- What is a command prompt and how do I get one?
- How do I read my e-mail?
- How do I change my password?
- How do I set my default printer?
- What program do I use to do ... ?
- How do I burn a CD-ROM?
- Where can I find documentation on Latex (TeTeX)?
- How do I create a PDF file from a Postscript or DVI file?
- How can I use graphics with pdflatex?
- How do I Move, Copy, or Delete a File from the Command Line?
- How can I post password protected web pages and files?
- How do I allow certain users access to my files? What are ACLs?
- How can I use PGP with Pine?
- How do I access my account remotely?
- How can I use VNC for remote sessions?
- Can you install linux on my home computer/laptop? Can you fix my home computer/laptop?
- Can I print from my laptop via the wireless network?
- How can I mount my home directory from my home Linux machine?
- How can I mount my home directory from my home Windows or MacOSX machine?
General Info
Hardware Resources
Basic Applications
Advanced Software Questions
Home Computers and Laptops
How do I get Help? Who do I call?
The best, fastest, and most efficient way to get help is to mail req@math.duke.edu with a description of your problem. This will send your message to all our systems administrators and allow them to respond from where ever they may be at the time. Email is by far the best way to reach us. You should receive an automated confirmation message letting you know the email was received by the system
Calling your Systems Administrator should be reserved for emergency situations.
We ask that you do this for a couple of reasons. First is that we are frequently juggling several tasks and a phone call essentially disrupts this process and forces us to address your questions immediately without time to think about it. You will get better, more complete, and more polite answers we are not interrupted regularly. If a more involved discussion is required, we can make an appointment and meet with you or arrange a call to work on the problem. The second reason is that it establishes a record of problems that we have worked on and solutions we have devised. There is nothing more frustrating than to have a user call with an unusual problem, which we work on solving and answering after recommending they use email, only to have another user encounter a simliar problem months later and we can't remember how we solved it the first time. Email creates a nice paper trail, especially for the administrator that didn't work on the problem the first time.
Finally, we are often not at our desks, but can get to email virtually anywhere. When possible, we answer your email as soon as we get it. We try to stay on top of problems and solve them as priority will dictate.
How do I get an Account? For a visitor?
Account applications are made online at https://www.math.duke.edu/cgi-bin/account. All regular members of the Mathematics Department (undergraduate major, graduate student, postdoc, faculty, or staff) are eligible. If an account is required for a visitor or someone who is not a regular member of the Mathematics Department, either apply online or have them apply online and be sure to include the name of a faculty sponsor and/or the number of a Mathematics Class for verification. We reserve the right to refuse any application.
How do I login? What are my options?
Logins are done through a graphical screen with fields for Username and Password. If the computer is at a text screen with a Login:prompt, then it is not ready for use. Try pressing ALT-F1 to see if the usual graphical screen comes up. If not, try another computer and email req@math.duke.eduso we can fix the problem.
To login, enter your username, press Tab to switch to the password field, then enter your password. Asterisks (*) will appear as you type your password so that others cannot read it. To login with the default environment, press Enter after entering your password. You can select the environment to login with by choosing from the Menu:button and then from the Session Typemenu. The most common selections are GNOMEand KDE although there are several other, less functional but also faster, desktop environments available.
How do I logout? How often should I logout?
What is a command prompt and how do I get one?
The command prompt is a text based application that provides direct interaction with the Unix system. It is similar in context to MSDOS or the Command Prompt window you can bring up on Windows systems. A listing of basic commands with documentation is available at http://www.math.duke.edu/computing/intro.html#BASIC. In general, most things can be done through the graphical user interface. But sometimes we will ask you, or it may be quicker and easier, to use the command prompt.
If you are using the KDE environment (the default), the command prompt can be found in the RedHat menu under System Toolsand is called Konsole. If you are using one of the other environments, ask us if you cannot find how to bring up a command prompt. As a shortcut, you can also press ALT-F2 which brings up a Run box. You can enter any command here that you would enter at the command prompt and it will execute directly.
From the command prompt, you can execute almost all programs by just typing the program name, sometimes with an argument such as a file to edit or display. For example, you can run the following programs by typing their command names :
- mathematica
- xmaple
- matlab
- firefox
- gpmail
- gaim
There are many more programs available than are possible to list. If you are looking for something specific, email req@math.duke.edu and ask, we'll be glad to help.
From the command line, we recommend pinebut mutt and mailare still available if needed.
Finally, from the Web you can access your email securely via Horde WebMailor TWIG.
How do I set my default printer?
You then need to add a line to a file in your home directory that the shell uses when you login.For the C Shells/bin/csh and /bin/tcsh you edit the file called .cshrcin your home directory. (If you are un sure how to do so, try the command gedit ~/.cshrcfrom the commandline). Add the following line to the end of the file :
setenv PRINTER lw0
where lw0is an example of one of the public printers. For the Bash Shell/bin/bash you edit a file called .bashrcin your home directory. Again, you can use gedit ~/.bashrcto edit this file from the commandline. In this file you add the following line at the end :
export PRINTER=lw0
where lw0is an example of one of the public printers.
You will need to logout and login again for this change to take effect.
How much disk space can I use?
Short Answer: New users have a home directory quota of 20GB. There is
no quota for local disk space in /xtmp or /ytmp.
Long Answer: In the last couple of years, the amount of disk space
required has doubled about once a year. While disk space is relatively
cheap, backup space (which is an absolute necessity) is not.
Thus our first step in this process is to try to eliminate from our backups
all files that really should not be backed up to offline storage. This
includes all personal MOVIES, MUSIC, PICTURES (those not intended for
web distribution on your personal page), and other such files.
We have three categories of disk space available to you (listed in order of
cost of resources, highest first) :
A) Home Directory Space (~username)
* Backed up nightly
* Available simultaneously from all machines
* Not as fast
B) Workstation Local Disk (/xtmp)
* Backed up nightly
* Fast
* Available only from local machine (or via ssh connection)
C) Workstation Local Disk (/ytmp) :
* NOT Backed up
* Fast
* Available only from local machine (or via ssh connection)
The /ytmp directory was created to accomodate the large amount of personal
files that are being created on our systems that have no business being backed
up nightly (or at all for that matter). If you need to have games, MP3 music,
RM, AVI, MPG, DIVX, or any other personal material on your office machine,
PLEASE PLEASE PLEASE put these files in /ytmp so that they will not consume
public disk space or backup resources.
A general rule of thumb is that email, papers you are working on, and code you
are writing that needs to run on several computers should be placed in your
home directory. Large files, data sets from code runs, archived documents,
and anything else that needs to be backed up should go to /xtmp. All other
files should be placed on /ytmp.
What is backed up and how often? How do I restore a file?
For a summary of what is backed up, refer to the FAQ on Disk Usage. Backups are done nightly at 1:30am, although due to the volume of data backed up may not complete until after 3:00am or later. We archive monthly backups for up to 1 year and yearly backups perpetually.
If you delete a file, or worse, many files, email req@math.duke.edu with a listing of what you need recovered and the approximate date of when you want the data recovered from. We will restore the files, possibly in a separate directory, and notify you when the data is available.
What program do I use to do ... ?
- Microsoft Office Files (.doc, .xls, .ppt): These files can be edited and created most easily with OpenOffice, run sofficefrom the command prompt. Alternatively, the programs abiword and gnumericcan handle Word and Excel files respectively, and may be faster than OpenOffice, but may be more or less compatible depending on the features of the files.
- LaTeX, TeX (.tex, .dvi): For editing TeX files, try kile or kwrite. They have context sensitive highlighting and other features to make editing TeX files much easier. Viewing .dvi files can be done with xdvior kdvi which both provide methods of zooming and printing.
- PDF (.pdf): The default application for PDF files is Adobe's acroread. But two other applications exist which may be used if problems arise with acroread. They are evinceand xpdf. Acroread is probably faster and is endorsed by Adobe, but there are documentst that cause it to have problems, here evince and xpdf may work better.
- MPEG-3 Audio Files/OGG Audio Files (.mp3, .ogg): Music files can be played from programs such as amarok, xmms, rhythmbox, gstreamer, and even the command line programs mpg123and ogg123. Be sure to check your volumes with mixers such as kamixor from the command line, alsamixer.
- Other Audio/Video Files: For other audio/video files, try playing them in totemor kplayer.
How do I scan a document into my account?
There are two ways available to scan documents into your account. Alternatively, there is a scanner hooked up to the Windows XP machine in room 102 that can be used. Instructions for this scanner are available here as well as posted above the computer attached to the scanner.
The command line programs mkisofsand cdrecord are also available for advanced users.
How do I reboot? Should I reboot?
How do I access my account remotely?
The second way is via the web. The suite of programs at https://www.math.duke.edu/secure/hordeprovides you with access to email, files, mail forwarding, vacation message management, a web proxy (coming soon), and SSH access.
Finally, the third way is via VNC. All systems should have VNC servers running on the primary X display which allow the owner of the console to access the display remotely. To do so, first create a vnc password by running vncpasswdat the prompt and entering a password twice. Now you should be able to connect to a screen by using a VNC client to connection to machinename:0 and entering that password. Note that you must be logged in on the system to use this method, otherwise root will own the console and you cannot connect. This connection can be slow and have problems, like multiple keystrokes registered for single keystrokes (run xset r offto fix and the xset r onwhen you are done, this disables/enables key repeat when you hold it down).
Since our department employs a firewall that blocks VNC, to use it from outside the department you need to tunnel your VNC connection over SSH. From unix, this is easy with RealVNC via the command vncviewer -via username@machine.math.duke.edu machine:0which will create an SSH connection as user usernameto computer machine.math.duke.edu and after asking for your SSH password, create the tunnel and ask for your vnc password to complete the connection. From Windows and MacOSX machines, you need to establish an SSH forward from local port 5910 to the remote machine you are connecting to port 5900 and then connect your VNC client to host localhost:10. Detailed instructions are dependant on the SSH client used to connect to the department.
How
can I use VNC for remote sessions?
Why VNC?
VNC is a remote display protocol that works well over slower connections. It willInitial Setup
let you run graphical programs such as Matlab and Maple remotely in a virtual session.
In addition, this session will continue to run until explicitly terminated. You use
a VNC viewer to connect to the session and control it but you can disconnect at
any time and return later.
First, connect via SSH to the machine you want to run your VNC sessionConnecting from Linux
on, cauchy.math.duke.edu would work or you can use the machine in your office
if you have one.
Once logged in, run :
vncserver -geometry XxY
where XxY is the resolution of the virtual screen you want to create,
800x600 or 1024x768 are good choices. The larger it is, the slower,
but over Duke LAN connections, it doesn't make too much difference.
When you run this command, it will return the screen ID to you,
something like cauchy:5. Remember this. This screen (cauchy:5) will continue
running until you expicitly kill it or the machine reboots so you can keep
connecting and using it. Just closing the VNC viewing window will not
kill the session.
Now set your VNC password by typing :
vncpasswd
and entering a password twice. You only need to do this once, after
that, the vnc password will be set for all future sessions.
Thats the setup part, now to connect to your screen whenever you want toConnecting from Windows
do some work, you need a VNC viewer with SSH capability.
If you are running linux on your machine, you can try connecting with
the command :
vncviewer -via username@remotehost remotehost:display
which following our example above would be something like (replacing joe_user with your username):
vncviewer -via joe_user@cauchy.math.duke.edu cauchy:5
This will ask for your SSH password first, then your VNC password.
The simplest way to connect to your VNC connection is by going to the link :Closing the connection
SSH/VNC Java WebStart.
This application does require that Java WebStart is installed on your system. This website can help you install Java WebStart if it is not already installed :
Install Java WebStart by Elluminate
When it has loaded, tell it to "Create a New
Connection" under the file menu, and connect to :
hostname : (whatever host you setup the vnc server on)
post : 22
username : Your Username
Then go to the VNC settings TAB and select "Linux/Unix Variant", leave
Host as "localhost" and set the Display value to the number of the screen ID
(in the example way up above, it was 5).
Then hit connect. Enter your Unix password for the first prompt, then your
VNC password for the second one.
Alternate Windows Connection
The Java based method has some disadvantages, no fullscreen support, some keys are not supported, etc. An alternate way that will provide fullscreen support as well as enhanced speed is to install the SSVNC viewer, available here :
SSVNC: SSL/SSH VNC viewer
Tell it to use SSH for the connection, use cauchy.math.duke.edu as the proxy/gateway, and connect to your VNC session you set up in the initial setup, in this example cauchy:5.
Just close the window when you are done and you can reconnect anytime later
and resume your session.
To really kill the VNC session, logout of the Panel and it will close the VNC
server.
Where
should I run large computational jobs? Do we have a cluster?
We do have a cluster of machines running Sun's Grid Engine software to
manage jobs. The machine grid1.math.duke.edu
through grid16.math.duke.eduare available for
running long computational jobs, but it is preferable to submit these
jobs through the Sun Grid Engine (SGE) interface on grid.math.duke.edu
so that resources are utilized with maximum efficiency. Read the
documentation for submitting and monitoring jobs at http://www.math.duke.edu/computing/sge_howto.html
To setup a personal webpage, here are the basic steps. Run these from a command prompt :
- First create the
directory ~/public_htmlif it does not already
exist.
mkdir -p ~/public_html - Next set the
proper permissions for the directory so that it can be entered by the
web server.
chmod 701 ~/public_html
You should repeat this for any subdirectories of ~/public_html that you create. - Now create a file
called index.htmlinside the directory
~/public_html using your favorite editor. kompozer
is a nice WYSIWYG HTML editor.
kompozer ~/public_html/index.html Create your home page using the editor and save it to disk. - Finally set the
permissions on index.htmlso that it is readable by
the web server.
chmod 604 ~/public_html/index.html
You should repeat this for any other files you place within ~/public_html. - Go to the URL http://www.math.duke.edu/~username/index.html replacing username with your login name and see if you get the webpage you just created.
Changing
your
Dynamically Generated Departmental Webpage
We have created a Faculty Database system that is designed to be a
central respository of all information
related to your employment with the Duke Mathematics Department.
Through the web interface at http://fds.duke.edu/db/aas/Math
you can enter
all sorts of information such as :
- Contact Information
- Picture of Yourself
- Degrees
- Research Interests
- Classes you are teaching
- Students you are mentoring
- Papers published
- Committees and other Activites
- Links to Personal Pages
- Submit your annual reports
- Plain Text Files : Just run lpr -Plw3 filename.txt
- Postscript Files : Use lpr -Plw3 filename.ps
- DVI Files : Use dvips -Plw3 filename.dvi
Where
are the public printers? Can I print from my laptop via the wireless
network?
Public Printers
There are 6 public printers in the department. A listing of these
printers, their locations, and other facilites available within the
department is available at
http://www.math.duke.edu/computing/facilities.html
Printing from the Wireless Network
The public printers are all accessible from the wireless network or
from any Duke IP address. You should use IPP
printing to connect to the server ipp://printhost.math.duke.edu
with queue name /printers/lw0for
example. Full instructions for connecting to these printers and what
drivers to use are available at http://www.math.duke.edu/computing/printing.html
Do
we have a scanner and how do I use it?
The department has a few of scanners available for your use.
The simplest method is to use
the photo copier. It is capable of
scanning many pages per minute and
will send you an email with a PDF attachment of your scanned document.
The only restriction is that scans will not be in color! Full
instructions are available at http://www.math.duke.edu/computing/copier.html
as well as posted in the copy room.
The is also a scanner in room 102 attached to the public
Windows XP machine. Login with your unix usename and password and then
run the program Photoshop from the desktop.
Further instructions are available at
http://www.math.duke.edu/computing/scanner.html.
Finally there is a scanner in the front office (Room 117) that
has a document
feeder available for scanning several
pages at once. Login to the Windows XP machine attached to this scanner
and use the program Acrobat to scan
directly into a PDF file. The front office staff should be able to
assist you with your scanning on this machine.
- ls: This command stands for List. If you type ls and press enter, a list of files in the currend directory will be displayed. Useful options include ls -Cwhich will show the list in a column format, and ls -lwhich will show the list is a long format with more information. You may also combine these with the option -a to show "All" files, including those that begin with a . and are thus called "hidden" since they do not display without the -a option, e.g. ls -al. Another useful option is ls -Fwhich will differentiate file types in the listing by adding a @ to links, a / to directories, and a * to executable filenames.
- cd : This command stands for Change Directory. If you have a subdirectory you wish to enter, you would type cd directory name. To go up a directory, you would type cd .. ( ..stands for one directory up, . stands for the current directory. )
- cp : This command stands for Copy. It accepts two arguments , source and destination files. If the destination filename is a directory, the file is copied to that directory with the same filename as the source file. E.g. cp filename ~will copy the file filename to ~ (your Home Directory).
- mv : This command stands for Move. It works similar to copy but the source file is removed after the copy.
- rm : This command stands for Remove. It can accept any number of files. E.g. rm test.1 test.2 test.3will remove the files test.1, test.2, and test.3.
- mkdir : This command will Make a Directory. It can accept any number of directory names. E.g. mkdir test final groupwill create directories test, final, and group under the current directory.
- rmdir : This command will Remove a Directory. In can accept any number of directory name BUT the directories to be removed must be empty.
How
can I use PGP with Pine?
It is possible to configure the pinemail
reader to use PGP (Pretty Good Privacy) Encryption when sending and
receiving mail.
Configuring PGP
-
You need to first create your PGP key. Type pgp -kg, select the
level of encryption, enter your name and your email address as shown in
the example, enter a Pass Phrase (Important, you will need to enter
this often, do not forget it), and then follow the directions on the
screen. This should tell you it has generated a key. It will store this
info in ~/.pgp. In general the defaults are sufficient.
Configure Pine to use PGP
- Start Pine and go into the Setup -> Config menus.
- The following is assuming the binary papp is located in /usr/local/bin. If not, please change the paths accordingly.
- Near the end of the configuration options, change
display-filtersto this value :
"-----BEGIN PGP" /usr/local/bin/papp -passfile _DATAFILE_ -key _PREPENDKEY_ - Then change sending-filters
to this value :
/usr/local/bin/papp -encode -passfile _DATAFILE_ _RECIPIENTS_ -key _PREPENDKEY_ - Now save the configuration and restart pine
Using PGP within Pine
Pine will automatically attempt to decode messages received that are encoded with PGP. It will prompt you for your passphrase and decode the messages automatically.To encode a message, compose you message as usual, but after hitting CTRL-X to send the message, you can either use the default filter (no encoding) or use the PGP filter by pressing CTRL-N (next filter). If you use the PGP filter, the message will be send encoded with the recipients PGP public key if available. If not, it will warn you that you don't have their key. To add keys to your PGP keyring, run pgp -hfor assistance.
Where can I find documentation on Latex (TeTeX)?
Check out this page LaTeX/TeX (Courtesy Michael Kozdron and Laura Taalman).
How can I use graphics with pdflatex?
See page 7 of the pdfTeX FAQ
How do I create a PDF file from a Postscript or DVI file??
How can I post password protected web pages and files? How
do I allow certain users access to my files? What are ACLs? How
can I mount my home directory from my home Linux machine? How
can I mount my home directory from my home Windows or MacOSX machine?
dvipdfm filename
dvips filename
By Default, dvips now creates a ps file rather than directing the file to the printer.
ps2pdf filename.ps
pstopdf filename.eps
acroread -toPostScript filename.pdf
or
pdf2ps filename.pdf
You might want to try both to see which result looks better for your particular document.
acroread filename.pdf
pdfedit filename.pdf
You can create subdirectories of your web tree in ~/public_html that
are accessible
only to those with a username and password you designate. Here are some
instructions and
warnings about this process at
http://www.math.duke.edu/computing/htaccess.html
ACLs are Access Control Lists. They allow you to set very fine grained
permissions on
files to grant permission for individual users, or groups of users, to
read or write
files that you own. Currently, you need to manage your ACLs from the
command prompt
and the configuration of ACLs is not trivial, it requires some
knowledge of how
permissions work on a unix system with regard to owners, groups, and
others.
The best documentation I have found is available online at this page on
Using
ACLs with Fedora Core 2. Start there and let us know if
you are
having any problems. We can update our documentation here to help
others if
you have any suggestions.
The best way to mount your department home directory on your home linux
machine is to use
the Fusekernel module and the Fuse program sshfs.
This is installed on all
machines manage that are running at least Fedora Core 4. If you need
help installing it
on another linux system, first check the
sshfshomepage for info and then check with us if you need
assistance.
To use sshfs, create a directory where you want to
mount your home directory on your
home machine, something like ~/mathis approriate.
Then run the command :
sshfs cauchy.math.duke.edu: ~/math
It will ask for your password (if your username is different on your
home machine from the
department, use username@cauchy.math.duke.edu: for the first argument
where username is
your user name on the department systems).
Now your math department directory is mounted on the directory ~/math
on your local machine.
When you want to unmount it you can either run the command :
fusermount -u ~/math
or in a pinch, kill the sshfs process that is running (killall
sshfswill work).
WebDAV stands for "Web-based Distributed Authoring and Versioning". It
is a set of extensions to the HTTP protocol which allows users to
collaboratively edit and manage files on remote web servers. What that
means is that you can store files in your home directory on the server
and securely access
them via standard https links for both upload and download. This allows
you to store a ICS Calendar file for use with applications like Apple's
iCal, Mozilla Sunbird, Evolution, KOrganizer, or any other WebDav
enabled calendering application. Furthermore, it provides a method for
mounting your home directory via the web on your home machine or
laptop. For further infomation, see our page on WebDav
Access.