Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!rice!rice!sun-spots-request From: imatron!manabu@uunet.uu.net (Manabu Tokunaga [c100]) Newsgroups: comp.sys.sun Subject: Response Summary - The Cure for "link down" Found Keywords: Networks Message-ID: <1990Oct8.001424.12261@rice.edu> Date: 7 Oct 90 21:30:00 GMT Sender: sun-spots-request@rice.edu Organization: Sun-Spots Lines: 35 Approved: Sun-Spots@rice.edu Originator: spots@walhalla.rice.edu X-Sun-Spots-Digest: Volume 9, Issue 341, message 12 A few weeks ago, I have posted a question as follows, and the cure is found. System : Sun/3 180 Sun OS 4.0.1 Problem : /dev/cua* occasionally goes into "link down" mode. Diagnosis: o There is no LCK_* file in /usr/spool/uucp. "tip" | uucp is not running. o Modem is working/ready. Power cycling it does nothing. o Likely to happen when tip is killed externally by a user (i.e. kill -9) o Subsequent tip execution results in "link down" messages from the system. The Cure: o Do a ps and look for processes. o Perform trace -p or gcore Discussions: Some participants have also discovered that this happens when a serial device (printer) connected to the cua* sends XOFF and then the tip is killed. At Imatron, we also found that a getty goes in when a video terminal user inadvertently presses CTRL-S and kills the login shell from another terminal in panic. XOFF has another profound effect - about a year ago we could not boot our Sun no matter what we did (reseated boards, checked disks). A few hours later we found out that console VT-100 was in XOFF mode. I thank you for all participated in this topic. Manabu Tokunaga, CS Dept. UltraFast CT Development Group/ Imatron Inc. 389 Oyster Point Blvd., South San Francisco, California 94080 Phone: 415-583-9877 X407