This question already has an answer here:
I upgraded to 16.04 from 15.10 today. Now I can no longer perform software updates. Running
sudo apt-get update results in the following:
Hit:1 http://archive.ubuntu.com/ubuntu xenial InRelease Get:2 http://security.ubuntu.com/ubuntu xenial-security InRelease [94.5 kB] Hit:3 http://archive.canonical.com/ubuntu xenial InRelease Hit:4 http://archive.ubuntu.com/ubuntu xenial-updates InRelease Hit:5 http://archive.ubuntu.com/ubuntu xenial-backports InRelease Fetched 94.5 kB in 1s (83.7 kB/s)
and it just sits there. I left it like this for 4 hours.
Top shows that after running the command,
appstreamcli goes to 100% cpu and stays there.
PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND 6741 root 20 0 120556 37456 9340 R 99.7 0.5 1:22.71 appstreamcli
Looks like I may not be the only one experiencing this...