manabu@uunet.uu.net (Manabu Tokunaga [c100]) (10/08/90)
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 <exiting> processes. o Perform trace -p <pid> or gcore <pid> 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 <exiting> 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