A/UX: Panic SBdrop Crashes Computer and Fix (12/94)


The A/UX 3.0 kernel on my Macintosh IIci, used to telnet into, hangs every two or three days. The computer writes this error to the console, "Panic SBdrop." The only way out of the hang is to manually restart the machine.

I upgraded to 3.0.1 and then to 3.0.2 using the patch I downloaded from the Apple FTP server. The system has been running now for over a month with full time usage, and I have not seen the kernel freeze since. I read once that there was a version of the A/UX kernel that did not freeze up when it received panics, and I wonder if that patch made it into A/UX 3.0.1? The only reason I ask is because I have not seen the console on the computer since I installed the new software, and I could still be getting errors but I haven't seen the computer lock up. I expect that the system upgrade solved the problem.

We think your concern would be taken care of by the AWS 95 Tune-UP 2.0, however, you must first upgrade to A/UX 3.1. If you have not installed Tune-UP 2.0, it can be downloaded for our ftp sight. Also you can get the Console under the Windows menu. These articles can help you locate the software update mentioned here:

* "Where To Find Apple Software Updates"
Lists online services for "free" Apple software updates.

* "Obtaining Apple Product Support in the USA"
Lists 800 numbers and online services for software updates, Apple
support information, and a subset of the Apple Tech. Info. Library.

Here are the fixes to the A/UX Kernel:

* The A/UX kernel no longer panics if more than four Ethernet interfaces
are installed.

* The console emulator no longer hangs if you stop <CTRL-S> the output.

* A kernel bus error, which could occur under heavy file I/O, has been
corrected.

* Certain I/O operations no longer cause the kernel fault handler to panic
the system.

* The FIONREAD ioctl no longer causes the system to hang when issued from
a background process.

* A problem which caused the kernel's asynchronous I/O data structures to
become corrupted has been fixed.

* NFS now maps client user IDs greater than 65533 to the anonymous user,
"nobody".


Support Information Services
Published Date: Feb 19, 2012