Andrew Morgan wrote: > On Wed, 30 Apr 2008, Jorey Bump wrote: > >> Wesley Craig wrote, at 04/30/2008 04:26 PM: >>> Two options: some motherboards have an entropy generator hardware >>> device; or, use the random device that doesn't block when entropy is low. >> I think Cyrus IMAPd uses /dev/urandom by default, but I'm not sure how I >> can confirm this. I didn't specify anything during compilation, and I >> can't find a runtime setting to explicitly select the random device, >> either. >> >> In any case, I can now faithfully trigger the problem by making multiple >> webmail requests until the browser hangs, then hold down the spacebar of >> the server's keyboard to build up entropy until the request is served >> and performance returns to normal. I haven't had a chance to check if >> this restores APOP, though. >> >> Maybe an IMAP proxy would help prevent the webmail from depleting the >> entropy, but I'm still wondering why this is a problem on this server >> running Linux kernel 2.6 and not my other IMAP servers running Linux >> kernel 2.4. I have an identical Linux 2.6 server that isn't having this >> problem, and the only difference is that it doesn't have Cyrus IMAPd on it. > > Cyrus IMAP calls out to the sasl libraries to generate the APOP challenge. > On my Debian Etch system, libsasl2.so uses /dev/random. That is strange! sasl in Debian Etch is compiled against /dev/urandom. And so my system confirms: cyrus:/usr/lib# strings libsasl2.* | grep random /dev/urandom /dev/urandom /dev/urandom /dev/urandom Rudy -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- Rudy Gevaert Rudy.Gevaert@xxxxxxxx tel:+32 9 264 4734 Directie ICT, afd. Infrastructuur Direction ICT, Infrastructure dept. Groep Systemen Systems group Universiteit Gent Ghent University Krijgslaan 281, gebouw S9, 9000 Gent, Belgie www.UGent.be -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- ---- Cyrus Home Page: http://cyrusimap.web.cmu.edu/ Cyrus Wiki/FAQ: http://cyrusimap.web.cmu.edu/twiki List Archives/Info: http://asg.web.cmu.edu/cyrus/mailing-list.html
