This has happened the second time this year. Suddenly, all the commands are broken - corrupted RAM maybe.
Reboot does help. However, it seems to me a possible sign of over selling at the host.
I run a few programs on it: steem voting, steem accounts. Not time critical.
Contabo is a bargin VPS - however, when things do not work as expected, their support is quite limited. Use their services with precaution.
Contabo support replies:
We can guarantee that this is not a hardware issue, please keep in mind, that your VPS it self is only virtual. The host server system is of course real hardware, but maintained and tracked from our side. Furthermore, we can inform you, that the current host system is completely healthy.
It does more likely seem that some services crashed and caused this behaviour. It could be helpfully, to check your log entries in this regard, accordingly to our tutorial:
https://contabo.com/blog/analysing-log-files/?utm_source=support&utm_medium=email