Hi Jesper, On Fri, Oct 16, 2020 at 12:28:13PM +0200, Jesper Dybdal wrote: > I run a few Stretch systems on old processors that do not support the RDRAND > instruction. > > Can I simply install "haveged" on the Stretch systems *before* the upgrade > to Buster to avoid problems during the upgrade?
In July last year I experimented with boot times on a virtual machine while: - running normally - disallowing RDRAND for early entropy - disallowing RDRAND entirely The normal boot (RDRAND) took ~1 second; the "no RDRAND at all" boot took ~49 seconds. Given that a virtual machine has no real hardware to provide sources of entropy I would consider this to be near to a worst case for SSH. If you have other boot-time services that require entropy then they may take significantly longer. So if it's mainly SSH you're worried about, I don't think this will be the end of the world for you to just do it and see what happens. https://strugglers.net/~andy/blog/2019/07/11/experiments-with-rdrand-and-entropykey/ Cheers, Andy -- https://bitfolk.com/ -- No-nonsense VPS hosting