Basic Information on the MPI-P Linux Computers

Please find additional documentation at

https://linuxdocs.mpip-mainz.mpg.de
https://www.mpip-mainz.mpg.de » Links » Intranet » hover above “MY INSTITUTE” » IT
https://thwiki.mpip-mainz.mpg.de (Theory group, user supplied documentation)

1. The Many PCs

Desktop computers are divided into new and newly installed “POLY ”computers, and a few remaining “LDAP” computers.

2. The Many Passwords

You get at least a “POLY” password for “POLY” computers and newer services and an “LDAP” password for older Linux computers and (still) for mail.

You might get additional passwords, e.g. for external access to the institute.

You can change the “POLY” password at https://vmadselfservice:8888 and the “LDAP” password at http://ldap.mpip-mainz.mpg.de/mpip.

3. Who can help me?

To avoid misunderstandings due to audio issues on the phone, email is the preferred way of support.

Primary contact for all IT issues is the helpdesk: (✉ helpdesk@mpip-mainz.mpg.de.

Access to the institute from the outside using ssh: Send the form to Account Administration
(✉ acctadmin@mpip-mainz.mpg.de)

4. Basic Information – mail, files, print

4.1. ssh from/to “LDAP” and “POLY” computers

To ssh from a “POLY” to an “LDAP” PC use the “LDAP” PCs full name, e.g. “ssh pckr232.mpip-mainz.mpg.de”.

To ssh from an “LDAP” to a “POLY” PC you can use the short name plus a “.poly”, e.g. “ssh pckr532.poly”

4.2. Mail

Your e-mail address looks like fuwa@mpip-mainz.mpg.de.

When starting Mozilla Thunderbird for the first time, enter your name, e-mail address, and your mail password. Thunderbird automatically determines the mail server settings. Please be patient; it takes Thunderbird a while to find the settings.

4.3. Disk Space

Your home directory is the most important disk space.

For large amounts of data, e.g. for simulation data you can get additional disk space on your PCs /usr/data directory or on bee14 (LDAP) or bee8 (POLY). This disk space is backed up each night, and can be recovered for up to three months in case of disk failure or accidental deletion.

Table 1: Choosing disk space
space	location	use for	speed
${HOME}	network	personal data	slow
/tmp	memory/disk	temporary data	fastest
/usr/data	disk in PCs	many small files	fast
/usr/scratch	thincXXX disks	temp. job data	fast
/data/beeX	network	big files	slowest

4.4. Printing

Your Linux desktop knows all theory group printers. The printers have a sticker showing their name. The theory groups color laser printer thps49 is in the K-bar.

The big color printers in 1.006 are CX923 and CX922.

5. Linux Desktops

Do not switch off desktops PCs. Backups are done in the night. If you want to save energy, switch off monitors, switch off room lights, turn down the heating, close windows.

The default desktop for Linux computers is the XFCE desktop environment. For web browsing and email there are Firefox and Thunderbird. Libreoffice is the standard office suite. Additional programs are e.g. Emacs, LaTeX, Python, Eclipse, Maxima etc. (Some of them in the /sw/linux directory.)

We also currently provide IceWM, Mate, and Gnome.

6. Linux Clusters

The Theory group has an Linux cluster of its own, the thinc cluster. You can read more information about the thinc cluster at https://max.mpg.de/sites/poly/Research/Experts/Pages/HPC-Cluster.aspx.

You can also get access to the MPCDF's computing facilities, e.g. the “Raven” and the “Cobra” supercomputers.

7. Working at home and on the road

7.1. Mail

You can use our webmail service:

https://rc.mpip-mainz.mpg.de

To use a program like Thunderbird at home, use the following settings:

For receiving mail, the protocol is IMAP, the server is mail.mpip-mainz.mpg.de, and the Port is 993 (using SSL and TLS).
For sending mail the server is smtp.mpip-mainz.mpg.de and the Port is 465.

7.2. Accessing resources at the institute

Electronic Journals: https://ejp.mpip-mainz.mpg.de

8. Odds and Ends

Wireless Lan: TODO
There are a public scanner and two copying machines in room 1.006.
To log on to other Linux computers without having to type your password every time, generate SSH keys and then make your public key an authorized key using these two commands (do not re-use the keys you get for SSH login from outside):
```
ssh-keygen -t rsa
ssh-copy-id -i ~/.ssh/id_rsa.pub localhost
```
To use rsync/scp when running compute jobs on the cluster you must use an empty passphrase.
To (a) avoid having to verify each host you log on to for the first time, to (b) store host names in the ~/.ssh.known_hosts file, and to (c) have your key-handling stuff forwarded to the system you connect to, create a file ~/.ssh/config with the following content:
```
StrictHostKeyChecking no
HashKnownHosts no
ForwardAgent yes
IgnoreUnknown UseKeyChain
UseKeyChain yes
```
(The last two lines are for MacOS users, but they don't hurt you if you don't use a Mac)