Frequently Asked Questions

1. too many files used

The number of files is limited on all file servers.

remove cache files you don't need (e.g. in ~/.cache)
pack git repositories (“git gc”, see git-gc(1)) — if you commit/push/pull often this can reduce the number of files a lot
zip the output of simulations which produce lots of files
use libzip, hdf5 when programming yourself
- also for evaluating the output of above

2. Debian 10

mpirun: oversubscribing slots

cat >hostfile <<EOF
localhost slots=37
EOF

mpirun --use-hwthread-cpus -np 9 ./hallo

mpirun --hostfile hostfile -np 38 ./hallo

3. I want to make movies from ppms.

Please use the script /sw/linux/os12.2/scripts/ppm2mpeg.

4. SAP using Firefox on Linux and BSD

Using the “User-Agent Switcher and Manager” Add-On IHateSAP

Mozilla removed the site-specific user-agent override setting from Firefox 71. You can still set the global user-agent (preference “general.useragent.override”). If you do not want this, you can use the “User-Agent Switcher and Manager” Add-On to set the user-agent string specific for the SAP system:

In the settings for the “User-Agent Switcher and Manager” Add-On check “Custom Mode” and enter this into the text field:

{
  "sbportal.sap.mpg.de": "Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:60.0) Gecko/20100101 Firefox/60.0"
}

Then click the “Save” button at the bottom of the page.

Reload your SAP tab, if already open.

Old firefox (version numbers below 71.0)

The SAP system used by the MPG – in its vast wisdom – knows that each and everyone of us uses “Windows 7” and “Firefox 60 ESR” as loudly proclaimed by 157 shrieking higher beings.

Alas, reality and SAP are non-convergent and con't meet, so, as SAP's implied proclamations are false, we may also tell lies to the SAP system.

To be able to use our SAP system in the firefox browser, do the following:

Enter “about:config” in the address bar of your Firexox Browser
Click the “I accept the risk!” button
right-click in the window, choose “New” and “String”
enter the preference name “general.useragent.override.sbportal.sap.mpg.de”
and as value “Mozilla/5.0 (Windows NT 6.1; Win64; x64; rv:60.0) Gecko/20100101 Firefox/60.0” (one line, no breaks)

Now you can use the SAP system until SAP gets wise again.