On Mon, Dec 03, 2012 at 03:11:21PM +0000, Karl Pielorz wrote: > > Hi, > > I have two SuperMicro E31220L based systems - both had identical > /etc/sysctl.conf - I then shifted them from 9.0-R to 9.0-Stable (as of > 2012/12/03). > > Now I've noticed of them complains at boot time that a bunch of OID's are > missing - and sure enough: > > " > sysctl kern.random > sysctl: unknown oid 'kern.random' > " > > But the other system returns these fine. > > One system ID's as 'Intel E31220L @ 2.20Ghz' - the other ID's as 'Intel > E31220L V2 @ 2.30Ghz' the V2 system is apparently 'missing' the kern.random > stuff. > > The only reason I can think for the OID's not being present is if one > system is using hardware RNG? - Though 'man 4 random' states: > > "The only hardware implementation currently is for the > VIA C3 Nehemiah (stepping 3 or greater) CPU. More will be added in the > future." > > Is there any other reason why they would have 'disappeared' on the non V2 > system? (in fact, looking at the Feature2 line I can see 'RDRAND' on the V2 > system, hmm so I'm guessing that's it?!)
You noted that RDRAND is supported by your hardware. And indeed, FreeBSD got the RDRAND (aka Bull Mountain) hardware random number generator support recently. From my reading of the sys/dev/random code, the kern.random OID is only instantiated if the software implementation is selected. If you prefer software, you can disable RDRAND with hw.ivy_rng_enable=0 tunable.
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