Re: [uml-user] UML guest hangs on sshd

[Jim C. <ji...@ma...>]

On Mon, 26 Sep 2005, Jeff Dike wrote:
> On Mon, Sep 26, 2005 at 05:24:30PM -0700, Robin Lee Powell wrote:
> > However, as soon as I run sshd by any means, the guest hangs.  I
> > have no idea what to do about this.  Help?
> 
> If not, then it might be an entropy shortage, and the UML random driver
> might be handy.

On my SuSE 9.3 installation, openssh-3.9p1-12 uses libcrypto-0.9.7 from 
openssl-0.9.7e-3.  According to their FAQ
	http://www.openssl.org/support/faq.html#USER1
the library will use /dev/urandom (or /dev/random if no urandom) to seed 
the random generator.  Thus it should not block even if entropy is 
exhausted.  Even so, UML's tend to have much lower entropy production than 
the host, like by a factor of 100, so the random pass-through driver is a 
really good idea.  

Hmm, /dev/urandom does exist within the guest, right?  If neither device 
can be found, libcrypto requires an initialization call which I didn't read 
the section about, but which probably involves hanging if it isn't done.

James F. Carter          Voice 310 825 2897    FAX 310 206 6673
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Email: ji...@ma...  http://www.math.ucla.edu/~jimc (q.v. for PGP key)