Re: Why does reading from /dev/urandom deplete entropy so much?

Mike McGrath
2007-12-04T20:53:48Z

Alan Cox wrote:
>> Here's the top 5:
>>
>> 266 28caf2c3-9766-4fe1-9e4c-d6b0ba8a0132
>> 336 810e7126-1c69-4aff-b8b1-9db0fa8aa15a
>> 402 c8dbb9d3-a9bd-4ba6-b92e-4a294ba5a95f
>> 884 06e84493-e024-44b1-9b32-32d78af04039
>> 931 e2b67e1d-e325-4740-b938-795addb45280
>>
>> The left number is times this month someone has submitted a profile with
>> that UUID. If we take the last one as an example has come from over 800
>> IP's in the last 20 days. It seems very unlikely that one person would
>> find his way to 800 different IP's this month. Let me know if you'd
>> like more.
>>
Background - Smolt runs this during its install:

/bin/cat /proc/sys/kernel/random/uuid > /etc/sysconfig/hw-uuid

For most users this would be run by the RPM %post scripts during install
from anaconda. For some reason there are some UUID's (like those listed
above) that come up more often then it seems they should if they are
truly random.

-Mike