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Seconded, it’s probably the fan. You can be sure, after checking oil and coolant of course, if it makes the same noise when cold at 6000 rpm (obv. don’t do this for long, just enough to confirm whether or not it’s RPM-related), then if first scenario didn’t give the right indication, check if the bike makes said noise when the fan just kicks on.
apt
on its own isn’t safe to use in shell scripts whileapt-get
is. At least, that is the output I get when usingapt
in a script on Debian.That is the only reason, for interactive sessions use
apt
, for automated scriptsapt-get
.