System Administration FAQ
Frequently Asked Questions
- Access to the PC pool byFAUCard?
- Why can’t I login?
- How do I type umlauts (äöü) on a US keyboard?
- How do I find more programs in Ubuntu?
- Which e-mail applications are available and how do I configure them?
- How do I set up e-mail forwarding?
- Can I print duplex?
- Can I print in color?
- Can I print on transparent sheets?
- How do I print .docx files?
- How do I cancel an already sent printjob?
- Why does Acrobat Reader report that there’s not enough disk space on my hard drive?
- How do I start Mathematica without owning a license myself?
- What to do if Firefox doesn’t start/shows an error message?
- Is LaTeX free and are there versions for other operating systems?
- Can I change the colors of the terminal?
- Where do I find or create (new) announcements?
- How do I recover old data from my HOME-directory?
- Are there video projectors? How do I operate them?
- My problem isn’t listed here. What should I do?
Login
1. Access to the PC pool via FAUcard?
Access to the PC pools via an activated FAU ID-card is only granted during the department’s office hours. Please visit Mr. Bayer (1st floor, room 01.330) with your current confirmation of enrollment in order to activate your FAU ID-card.
Service hours:
Mr. Bayer | Room 01.330 | Mon – Wed | 09:00 – 11:00, and Mo – Thu 14:00 – 15:00 |
2. Why can I not log in?
In case you cannot log in, try these steps:
- When prompted to enter your password, select the correct keyboard layout from the dropdown menu (default: US).
- Check after typing your login name whether the operational aid is deactivated (bottom right: blue circle with a white figure)
- Exceeded your disk space quota? See here.
- If you still have trouble logging in, ask us directly at room 01.330 or call us at 67335.
Ubuntu
1. How do I type umlauts (äöü) on a US keyboard?
The Compose key can be used for this: The compose key.
As these keys do usually not exist on a standard English keyboard, another key has to take the role of the mentioned compose key. Open the dash (Windows key) and look for the Keyboard settings. The tab Shortcuts gives the option Typing where it is possible to change the compose key.
2. How do I find more programs in Ubuntu?
The default user interface is Unity. To find more programms, the Dash is used:
- To open the Dash, press the Windows key. Alternatively, click on the Ubuntu logo in the top right corner.
- The dash offers a selection of default applications (e.g. Firefox, Thunderbird) when opened.
- The search bar can not only be used for searching for programs but also for searching for simple applications (such as “mail”, “web”, “terminal”, “document”).
- It is also possible to click through to all the applications via the “More Apps” button.
- The menu bar can be found on the right side of the user interface. If it disappears, move the cursor to the left side to blend it in again.
- If you use a particular program frequently, it might be convenient to permanently add it to the task bar: Right click on its icon in the task bar (while it’s open) and choose “Keep in Launcher”.
- To open a terminal, press Ctrl + Alt + T
1. Which e-mail applications are available and how do I configure them?
- Thunderbird settings:
When setting up a new e-mail account in Thunderbird, you begin with the Accounts Assistant, which appears automatically when you start it for the first time or can be opened manually via “File ➔ New ➔ Existing Email Account”. Enter your name and your correct e-mail address here. The associated password for access to your mailbox must also be entered correctly. Next, click “manual config” on the bottom left of the window. After that, you can enter the following data. It is important to ensure that the “Authentication Method” (see box below) applies to both servers (incoming and outgoing). The line beginning with “Username” can only contain the username (the email address without @math.fau.de).
Outgoing Server | mail.math.fau.de |
Port | 587 |
Connection Security | STARTTLS |
Authentication Method | Normal Password |
Server Settings | imap.math.fau.de |
Port | 143 |
Connection Security | STARTTLS |
When first started, always select Confirm Security Exception |
- mutt config files: muttrc, msmtprc have to be set as .muttrc and .msmtprc in the home directory and have tp be adjusted to the personal information.
- webmail: math.fau.de/webmail , mail.math.fau.de/webmail
Setting a wrong “reply to” email address can cause your emails to stop arriving.
It is recommended to use the webmail as it can be used with every browser and no configuration is needed.
2. How Do I Set Up E-Mail Forwarding?
If the following information is not sufficent to configure the forwarding or further problems should arise, kindly write e-mail to: problems@math.fau.de
Roundcube Webmail – Forwarding e-mails
To forward the e-mails of your account to a certain e-mail address , follow the upcoming instructions:
- On the right corner, you’ll find a symbol which is called “settings”, click on it
- On the left side you will find a menu. Click on “server settings” and then on the tab “Filter”
- Now a list with all your filters can be seen. (These filters are processed from top to bottom. Disabled filters are displayed in gray, enabled ones in black)
- Click on the plus sign which can be found on the bottom left to add a filter
- Choose a unique filter name
- Click on “all messages” for “Incoming mail”
- Select the wanted option (Redirect mails to/Send a copy to)
- In the text field, enter the e-mail address to which the messages should be redirected.
- Make sure the option “Filter enabled” is chosen
The filter has to be activated. Select the filter in the first list, click on the checkbox if it’s “enable”. After all settings are adjusted, save your options.
Important note: To avoid complication, please delete old or deactived filter sets. After using the option to forward all e-mails, the other filters will be disabled. For still being able to be used, the filter sets have to be moved above the forwarding rule.
Source: www.rz.uni-greifswald.de
Roundcube Webmail – Set up a Vacation Mail
To set up a vacation e-mail, follow the upcoming intructions.
- The option “Setting -> Filters” offers a list called “Filters” (These filters are processed from top to bottom.. Disabled filters are displayed in gray, enabled ones in black)
- Click on the plus sign which can be found on the bottom left to add a filter
- Choose a unique filter name
- Click on the filter in the second list
- Click on “all messages” for “Incoming mail”
- Select the wanted option “…execute the following actions” -> (Reply with message)
- Write the message in box which will appear
- (optional) “How often send messages” (in days) is an option to set a period of time after which a sender will receive a vacation message, however how many mails were sent.
- Make sure the option “Disabled” is not choosen.
- The filter has to be activated. Select the filter in the first list, click on the symbol for settings below the list to choose “enable”. After all setting are adjusted, save your options.
Note: Do not delete the set filter after your absence, just disable it. It can be used again.
Printer
1. Can I print duplex?
You need to choose the right option for that: printer-nn-ds.
2. Can I print in color?
The printers printer-68, printer-81 and printer-82 are able to print in colors (printer-nn-color or printer-nn-color-ds).
3. Can I print on transparent sheets?
Yes, this is possible. For this option, you need to use a Lexmark printer.
- Open the manual tray at the front, pull to open it.
- Slide in the transparent sheet with the border on the right-hand side to match the marking.
- In your document viewer, select manual tray as “paper source” and transparencies as “paper type”
- Now you are able to print the document.
- On the printer’s user interface, press on status/supplies” (bottom left): Do not prompt, paper loaded.
4. How do I print .docx-files?
To print .docx-files with Libre office, follow the upcoming instructions:
- In the menu File select “Export as PDF…“,
- Click on “Export“. Choose a location to save it.
- Open the .pdf file with evince or okular to print the file.
5. How can I cancel an already sent printjob?
To cancel a printjob, follow the following instructions
- On the menu bar, click on the Ubuntu symbol to open the Dash. Use the search bar to look for “printers”.
- Click on the printer symbol – a window will open with all the available printers
- In the menu bar click on printer “Printer” . A drop menu will appear. Select “View Print Queue”
- A window with a list of all the printjobs will open
- By selecting your own printjob, you are able to delete it
Programs
1. Why does Acrobat Reader report that there’s not enough disk space on my hard drive?
This is a bug in Acrobat Reader. All the home directories are stored on a 30 terabyte file system. Trying to find a free location the reader cannot handle the size of space and Acrobate Reader misinterprets the warning.
Solution: Save the file on local drive (such as /tmp) and move it to your own home directory.
Or simply use another program to open the file such as evince or okular.
2. How do I start Mathematica without owning a license myself?
You can simply relate Mathematica to the RRZE’s license server. Select “Other ways to activate” and “Connect to a network server”.
Enter
license2.rrze.uni-erlangen.de
in the text box. Click on “Activate” and accept the license conditions.
3. What to do if Firefox doesn’t start/shows an error message?
This can have serveral causes:
- Students: You use more than 3 GB in your home directory:
Solution: By pressing Ctrl-Alt-F1 you change to a virtual console. There, log in (US keyboard!) and remove unnecessary files. The command “du -sh .” shows the size of the current directory.
Tutorial
- A session was terminated unexpectedly.
Solution: Runcd .mozilla/firefox/xxx.default/
(xxx=Name of Directory) and remove the broken file .parentlock via:
rm -r .parentlock
- The user’s profile was damaged, probably by a crash.
Solution: Make sure Firefox is closed. Open the profile manager by “firefox -ProfileManager” and create a new profile. Saved bookmarks can be recovered via “Bookmarks/Show All Bookmarks/Import and Backup/Restore/Choose File…” and selecting a file in “.mozilla/firefox/xxx.default/bookmarkbackups/“.
4. Is LaTeX free and available for other operating systems?
Yes on both counts. You might want to look for “latex *prefered OS*”.
For more Information about LaTex visit www.ctan.org.
For an overview of LaTex commands and more go to https://en.wikipedia.org/wiki/Help:Displaying_a_formula.
5. Is it possible to change the color scheme of my terminal?
On default-settings, open gnome-terminal (Ctrl-Alt-t), select Edit on the menu bar and go to Profile Preferences: a new window will show up. Select Colors to enter your prefered color scheme. Most commands used in terminal will use these settings.
Website
1. Where can i find and create (new) announcements?
It is not possible to create new announcements by using the old script.
Please use the Department’s calendar.
To obtain a frontend account please contact neuss@math.fau.de.
A Caldav server has been set up at the Department of Mathematics. This is a network application that communicates with various calendar programs (Thunderbird/Lightning, Evolution, AppleCalendar, Microsoft Outlook, …) and provides calendars that can be integrated by users into their personal calendars.
Backups
zfs
Alongside other backup solutions we are employing zfs. Therefore, every user has access to a recent snapshot of his HOME directory. To access old files please proceed like this:
If you are a staff:
- At the directory /home/staff of all staff members there is a directory called /.snapshot. Please note that it is a hidden directory. Therefore, it will not show up in your default file explorer, but can be accessed by the following command.
cd /home/np1/staff/.snapshot
If you are a student:
- At the directory /home/stud of all student there is a directory called .zfs/snapshot. Please note that it is a hidden directory. Therefore, it will not show up in your default file explorer, but can be accessed by the following commands.
cd /home/stud/.zfs/snapshot
In this directory you can browse snapshots with different timestamps. Backups are made hourly, daily and weekly. The type of backup is determined by the point in time upon saving: e. g. hourly backups are kept for a week, weekly backups for half a year. The copy of the HOME will always be saved in the exact state it was currently in. Thus only changes older than an hour are saved. The format for the students is as following:
Year-Month-Day-HourMinuteSecond
For example if you are trying to access your backup dating back to the 10.08.2013 your prompt should look like this:
cd snap-weekly-1-2013-08-10-030146
Next enter your home directory:
cd /home/stud/.zfs/snapshot/snap-weekly-1-2013-08-10-030146/username
Here you can find all backups dating back to the desired point in time.
The format for staff is as following:
hourly.nr, nightely.nr, or weekly.nr the numbers are starting with 0 for the newest version. So for example if you go to hourly.0 you will get the backup from an hour ago.
cd /home/np1/staff/.snapshot
- Attention! For the computers in the computer labs and partly for the staff’s computer, a new system is used for the snapshots. The snapshots are taken every six hour. The procedure remains the same, just the folder’s name differs. Instead of snap-weekly-1-2013-08-10-030146 it is called auto-20190820-060000. The new format is now auto-DATE-CLOCK.
Restore old files
Stored data comes in form of snapshots. This means all data in .zfs/snapshot/snap-weekly-1-2013-08-10-030146 is read-only. Though it is possible to copy old files into your home.
cp /home/stud/.zfs/snapshot/snap-weekly-1-2013-08-10-030146/username/testfile /home/stud/username/testfile_2013-08-10
alternatively:
cp /home/stud/.zfs/snapshot/snap-weekly-1-2013-08-10-030146/username/testfile ~/testfile_2013-08-10
For staff:
cp /home/np1/staff/.snapshot/weekly.0/username/testfile /home/np1/staff/username/testfile_1week_ago
alternatively:
cp /home/np1/staff/.snapshot/weekly.0/username/testfile ~/testfile_1week_ago
Tips
- You can compare different versions of a file with diff:
diff testfile1 testfile2 |less
To redirect differences to a file:
diff testfile1 testfile2 > differences
The following example compares a file from your HOME directory to another file from the backup directory. diff compares files line by line; the output contains the differences:
diff /home/stud/.zfs/snapshot/snap-weekly-1-2013-08-10-030146/username/testdatei1 ~/testdatei2 |less
How to create a symbolic link in your home directory:
ln -s /home/stud/.zfs/snapshot/snap-weekly-latest/username backup-snap-daily
Miscellaneous
1. What must be considered when using a video projector?
Facility Management (Tel.: 27777) manages all video projectors in the lecture halls and seminar rooms.
Pay attention to your orders of action (booting projector, pluging in video ports, …). Proceed as following:
- Turn on projector and computer
- After both devices are fully booted, plug in the video projector;
2. I have a different problem. What do I do?
Please contact us: problems@math.fau.de.
3. Password generator (reload for new password):
4a3t$Tw,rYEetAnpXceqWbhF
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