I am working on a project* in which I need to fake a pendrive so that it looks like if it was used for several years. That means copying files, making directories, removing them and so on. It needs to be done in such a way that all dates looks OK, which makes it less trivial than it sounds. While the pendrive is FAT formatted and tries to look as if it was used under Windows, it is easier to script the operation under Unix. I have Debian installed in VBox. And here is the problem - I am unable to stop Debian from synchronizing time. I already did it in the spring, then using timedatectl set-ntp false to stop NTP was enough. For some reason now after several operations/seconds (not sure yet what it is that triggers synchronization) my system clock is back to the current. Any idea how to stop the clock from synchronizing? Note: the most obvious approach to setting up dates (using touch) doesn't work - it sets up only one of three dates assigned to every file in FAT, so for someone savvy it is obvious it was tampered with. *In case you wonder - here is the project page: facebook.com/PDZWT (in Polish), first version was published in June, but it contained some mistakes and I want to start from scratch.