> From: [email protected] [mailto:discuss- > [email protected]] On Behalf Of Stephen Adler > > I've run across an interesting situation at where where I'm required to > encrypt my desktop at home since it's owned by the government. Any > advice on how to best setup an encrypted linux system? Preferably using > some kind of encrypted hardware device which will not kill my disk IO > rate?
If you enable encryption on your disk, it does not harm your IO rate. I've measured, benchmarked, evaluated many configurations on many systems, and it comes down to this: If you have a CPU which lacks the AES-NI instruction set, and you absolutely max out IO to a single disk, then it consumes about 30% cpu utilization on a single core, which means your performance is still limited by the disk IO and there is no measurable IO performance degradation. You can stripe or mirror 3-4 disks into an aggregate unit, before you finally reach the computation limit on a single core. I have not tested performance after you actually reach the limit of a single core - I suspect that some systems probably scale well to utilize multiple cores, and I suspect others do not. If you *have* the AES-NI instruction set, then you get about 6x-10x faster encryption. So, it would take around 18-40 disks all maxing out IO, before you are performance limited by your CPU. And in the typical situation, where you have only a single disk system, plus a CPU with AES-NI, you literally cannot measure the performance difference, nor the CPU overhead of performing the encryption. Because the 3% or so CPU utilization falls into the noise, below the radar, along with "top" or whatever tool you're using to measure CPU utilization. _______________________________________________ Discuss mailing list [email protected] http://lists.blu.org/mailman/listinfo/discuss
