Computing

COMPUTING

The Department of Statistics shares a High-performance Computer Cluster with the Department of Astronomy. The cluster has 256 processors running Linux, using Condor as a scheduler, and is intended for research use only.

Please contact Dood Kalicharan (dk@stat.columbia.edu) for access if you are interested in using this machine for your research projects.

Department Computing FAQ

Where can I find the system administrator?

Our system administrator is Dr. Wuyi Liu. He comes to the department every Tuesday and Friday, while he is always accessible through email liu@phys.columbia.edu. His office in our department is room 926. Or you can ask Dood or Anthony where you can find him.

How can I access my email?

When you login to the unix account, you use the "pine" command toaccess email.

When you access email from your PC, there are a number of email clients you can choose. Learn more about your options and how to configure them at http://www.columbia.edu/acis/email/pcmail/.

The incoming mail server is: stat.columbia.edu either pop3 or imap, without SSL. The outgoing mail server is: send.columbia.edu with SSL, with authentication, and the authentication takes your CUNIX id and password.

There is atutorial about authenticated smtp at http://www.columbia.edu/acis/email/authsmtp/

Where can we find tutorials about basic computing stuff, such as changing password on Unix, setting Netscape Messenger on my laptop to read email?

ACIS provide tutorial for them and much more at

http://www.columbia.edu/acis/publications/handouts.html

Can my files on the Unix server be accessed by others?

By default, your mails including your inbox and saved mail folders cannot be accessedby others. All other files can not be altered by others, but can be seen by others. You can change file/folder protection mode with the command "chmod". You can learn how to use it by the command "man chmod".

If you don't want others to read any of your files, put "umask077" in your startup file,

and run "chmod -R go-rx *" once.

To make your homepage still available to others, run "chmod og+rx public_html" afterwards.

When you use the secure shell client downloaded from www.ssh.com (see below) to upload files from you PC to the Department server, you will also need to configure it to make sure your uploaded files won't be readable by others. To do that, in the SSH Secure Shell client, click Edit -> Settings, look for "File Transfer" part in the left,then click "Advanced" beneath it, then on the right part, change "Default file permissions" to 600, and change "Default directory permissions" to 700. Then click OK. Then click File -> Save Settings.

If this is too complicated for you to figure out on your own, please ask Wuyi to customize the folders for you by visiting his office during his hours in our department orsend him an email request.

Telnet and Ftp

Currently stat.columbia.edu forbids telnet and ftp access. This is due to security reasons. When connecting through telnet or ftp, your password is transferred in clear text, which will put the whole system at risk. The replacement is secure shell access (ssh).

If you access from your pc:

You need to download and install windows secure shell client.

Download SSH client from ftp://ftp.ssh.com/pub/ssh/.The current release version is SSHSecureShellClient-3.2.0.exe. After installation, you will find a secure shell client anda secure file transfer client on your desktop. They can be taken as the secured version replacement for telnet and ftp. To login or to do file transfer to department server, you connect to “stat.columbia.edu” or “wald.stat.columbia.edu”.

If you access from another unix machine:

”sshliu@stat.columbia.edu”

is the secure replacement of "telnet stat.columbia.edu"

”sftp liu@stat.columbia.edu“

is the secure replacement of "ftp stat.columbia.edu"

(note the syntax is slightly different, ie, you need to specify your username on the remote site)

If you access from a pc in the institute youare visiting:

In case ssh client is not installed on that pc, you first telnet cunix.cc.columbia.edu to your ACIS account there, and then use ssh of sftp to access stat.columbia.edu.

The new cunix cluster in the testbed also forbids telnet. When the switch to the new cunix cluster happens, you might want to give a gift to your host - install a secure shell client for them!

If you access from Mac OS:

The underlying operation system of Mac OS X is based on BSD Unix, which has built-in ssh support. The command line is identical to the unix commands mentioned above.

Printing

The printers in the department are:

NameFeatureRoomIP

lwdood0B&W1005 SSW128.59.111.13

colorlpColor 1005 SSW128.59.111.14

(canon, pc only) B&W 1001 SSW128.59.111.15

on Unix:

print file a.ps tolwdood0: lpr -Plwdood0 a.ps

check queue status of lwdood0: lpq-Plwdood0

if you want to send dvi filea.dvi directly to the printer lwdood0, put the following line:

alias dvips '\dvips-Plwdood0'

in your startup file. (If your login shell is csh or tcsh, your startup file is ~/.cshrc.

Read http://www.columbia.edu/acis/webdev/unix/index.htmlif you want to learn more about unix.)

Then you can use the following command to send a.dvito the printer lwdood0: dvips a

on Windows:

see http://www.stat.columbia.edu/~liu/print.htmlfor instruction on setting up printer on your pc.