On Mon, May 31, 2004 at 03:17:30PM -0400, Scott wrote: > If I try to ping a host on the internet (e.g. freebsd.org), I > get all the packets, but the output of the command doesn't > begin for at least 10 seconds. If I try startx, it takes about > 30 seconds just to begin to display the root window. Even > backspacing seems much slower. > > While this is going on, no unusual processes are running and > the CPU is practically unused. Nor is it merely a matter of > delay--the CPU usage never spikes up like it normally would. It > just sits mostly idle while the command I've issued takes a > long time to complete.
This sounds to me a lot like DNS trouble. If for some reason the first listed nameserver in your /etc/resolv.conf was not working correctly, but the second or third one was, it could have the result you describe: a lot of commands mysteriously hang for what feels like forever, but is usually less than a minute. > I can always tell when the problem will occur based upon what > happens at boot. There are no error messages, but the slowness > begins when the standard daemons are loading. Cron and sshd > load just fine, but the delay occurs as sendmail loads, and > there is another delay as sendmail-clientmqueue loads. Once > that happens I know I'm in trouble thereafter. Yup. sendmail is a very heavy DNS user and it won't start up without doing lookups on a load of stuff. sendmail hanging on startup is pretty much diagnostic for DNS troubles. > I know this isn't much to go on, but does anyone have any clue > on what I might try? Thank you. Are you using DHCP to configure your network interface? That should create a /etc/resolv.conf file for you automatically. In that file you should see at least two 'nameserver' lines containing the addresses of some DNS servers provided by your ISP. You can test whether your system can do lookups via those servers by: % dig @126.96.36.199 www.freebsd.org where '188.8.131.52' should be replaced by each of the nameserver IP numbers from /etc/resolv.conf in turn. If things are working correctly you should get a response in a few milliseconds. If you can confirm that is the problem, then you may be able to edit the /etc/resolv.conf file and reorder the nameserver lines so that a communicative server is listed first. That however is just a band-aid and you will need to find out why your ISP's servers cannot be queried. Make sure you check your firewall configuration carefully -- it's very embarassing to complain to tech support and then find that it was you blocking the traffic all along. Cheers, Matthew -- Dr Matthew J Seaman MA, D.Phil. 26 The Paddocks Savill Way PGP: http://www.infracaninophile.co.uk/pgpkey Marlow Tel: +44 1628 476614 Bucks., SL7 1TH UK
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