TDDI41 Introduction to System Administration: Labs

Frequently or sometimes asked questions (and ugly hacks)

ANY LAB: SEGFAULT in apt or corrupt package list

Have you checked that sources.list contains ftp.se.debian.org instead of debian.ida.liu.se? If not, make sure to have the debian.org address. Then do apt update.

ANY LAB: Kernel panic! ...locked by... PID=0

This often happens when the UML instance isn't shut down in a fit and proper manner.

An ugly hack that appears to break this:

Create a subdirectory of /tmp, eg /tmp/yourname
Use rsync --sparse to create a copy of the cow files from ~/uml in the temp directory.
Synchronisze the files back with rsync --sparse.

That is, create a new file (as tmp is on another file system), and overwrite your original cow file.

NET: Our network is mysteriously failing

Did you happen to select static IP addresses that might conflict with the ones provided by IDA's DHCP server? 10.0.0.0/8 should be OK.

(wondering what the /8 stuff is about? Check out eg Subnetwork on Wikipedia, and a Reserved addresses list)

DNS: Our resolv.conf - with domain info - on the router is overwritten every reboot!

Hint: this is the only host with dhcp enabled. Does the DHCP client need to get domain, search,... information? Check conf files in the /etc/dhcp/ directory for clues.

Page responsible: Anders Fröberg
Last updated: 2018-11-16