COMP3000 Operating Systems W23: Tutorial 7 Not Using SCS OpenStack

If you are not using our course VM for some reason, you might encounter problems and you can refer to the instructions below. Although they are by no means comprehensve to solve the problems, they can in many cases and serve as pointers about where to look.

Modules fail to build

If you see errors (not just warnings) after running make and no .ko file is produced, you may have installed a version of Ubuntu that is too minimal. But you can fix it by installing the right packages. Do the following:

sudo apt update

sudo apt dist-upgrade

sudo apt install build-essential

sudo apt clean

If your build failed before doing this and again after, delete the downloaded code and unpack the zip file again.

Disk full

If you find your disk space filled up, you can use the following command to pinpoint the top 20 largest files (no need to understand the specifics unless you are curious):

sudo find / -type f -exec du -h {} 2>&- + | sort -rh | head -20

Or including directories:

sudo du -h / 2>&- | sort -rh | head -20

Command 'bpftrace' not found

You may be able to fix this by installing the bpftrace package (just the frontend and the examples):

sudo apt-get install bpftrace

Use its equivalent on other Linux distributions.

Note: it could be much worse than this, e.g., not having the right kernel compiled with eBPF support, for which there won't be a quick fix. In such cases, you are suggested to move to the course VM or choose a different VM of your own.