Today I noteced that between 10-20 our CPU is at 100% and up to 320%!!!!

And today I can ses the same; spiked with CUP of 150%-200%.

What´s going on? Are we under an attack?

Bandwidth is also consumed following the same graphs as the CPU load.

I tried to look in Apache2 logs etc but cannot find anything...

I'm a Linux newbie - where else can I look for logs and what can we do to stop this?

Same thing here (ony one linode). CPU & BW spiked from 4h00 am EST to around 6h30am EST, when the server stopped responding. Nothing special in my logs (apache, ssh, postfix, ...) after a reboot during that period.

I hope linode will credit us for the bandwidth as this as taken around 46GB in just 2 hours and 1/2.

Do someone have any suggestion on which log, which command I can use to check what and who is using the CPU and bandwidth?

You can use the command 'top' to see what's using CPU. You can sort by other things too. 'M' (capital) will sort by memory usage.

Newbies better off with htop rather than top. htop is more intuitive.