Re: kernel: Entropy device is blocking

[sam <samwun@xxxxxxxxxxxxxxxx>]

Joerg Sonnenberger wrote:

> On Fri, Jan 28, 2005 at 09:57:49PM +0800, sam wrote:
>
> > Every now and then when I freshly install FreeBSD, I sometimes get an 
> > error message saying "kernel: Entropy device blocking" when I turn on 
> > sshd in rc.conf file. I have search around in google but coudln't find a 
> > right fix for it.
>
>
> The problem is that during boot, only a small amount of entropy
> is generated. Since sshd depends on full random bits, it can't
> and doesn't the normal /dev/urandom. /dev/random can block, if
> not enough random bits are available.
>
> I'm not sure what triggers the omission of a normal entropy
> level for you. It could happen in a low-irq environment like
> pure ramdisks or so, it might be enough to just create some process
> doing nothing. Very difficult to say. One idea to find out the 
> amount of entropy needed is changing the rc.d script to run
> sshd under ktrace and check for the read calls to /dev/random.
It may be the problem with the hardware. I install the system in a old 
and dirty PIII machine. I m going to install it in the IBM notebook and 
see if this makes any difference.

Thanks
Sam.

> Joerg