In between dying quietly from acute viral nasopharyngitis (as supplied in various varieties by my three year old daughter) and trying to earn a crust or two I’ve been playing with the Amazon Elastic Compute Cloud (EC2).
One of the things you notice when you run up a relatively recent Linux distribution is that there is a new CPU %age shown when you run ‘top’. The mysterious ‘st’.
It turns out that this stands for ‘Steal Time’ and is the amount of real cpu that the Xen Hypervisor has allocated to tasks other than running your Virtual Machine (such as somebody else’s VM…).
So if your AMI doesn’t have this statistic in ‘top’, and isn’t reporting ‘Stolen CPU ticks’ in ‘vmstat -s’, then you need to upgrade your ‘procps’ tools to a later version.