Re: Entropy Pool Contents

Gunter Ohrner
2006-11-23T21:41:27Z

Jan Engelhardt wrote:
>>Hornburg:~# cat /proc/sys/kernel/random/entropy_avail
>>0
> You really must have bad luck with your entropy...

IMHO something really fishy's going on there. If I explicitely write data
into the pool, it shouldd not stay at "zero", from wwhat I understood about
how /dev/*random work.

> Disk activities are "somewhat predictable", like network traffic, and
> hence are not (or should not - have not checked it) contribute to the
> pool.

Well, they do, block device operations do, using the function
add_blkdev_randomness, as far as I know.

> Note that urandom is the device which _always_ gives you data, and
> when the pool is exhausted, returns pseudorandom data.

I know, and running on deterministically computed random values only for
days in a row is no situation I'm paticularily happy about...

I'm mainly wondering why writing stuff to /dev/*random does not change the
entropy from zero to at least any low non-zero value...

Greetings,

Gunter