johnson@EULER.JSC.NASA.GOV (Stan Johnson) (03/26/91)
We have an IRIS 4D-25S set up as a fileserver (running 3.3.1). We have an intermittent problem reading tar files from cartridge tapes: the message "WARNING: dma_map: address C055FFFF not word aligned" will display over and over until the machine is reset. This is not at all repeatable, and our field service person was not able to find any problems after running all the diagnostics. It seems like a memory problem to me; any ideas on how I could force the error so that our field service person can fix whatever needs to be fixed? Another, possibly unrelated, error that I haven't been able to track down is the message "NOTICE: plp/audio: unexpected interrupt", which appears every few days on the console. Any help on this will be greatly appreciated.. -Stan Johnson NASA / Johnson Space Center Houston, Texas 77058 (713) 483-4692 johnson@euler.jsc.nasa.gov
sweetmr@SCT60A.SUNYCT.EDU (michael sweet) (03/27/91)
> We have an IRIS 4D-25S set up as a fileserver (running 3.3.1). We have an > intermittent problem reading tar files from cartridge tapes: the message > "WARNING: dma_map: address C055FFFF not word aligned" will display over > ... We had the same problem on our 4D/20 when we first added another SCSI disk. Turned out that the SCSI cable we bought was a Mac SCSI cable; these cables only carry enough of the standard SCSI signals as are necessary for the Mac SCSI port (not that much!), and don't work with true SCSI ports... Another possibility is that the terminating resistor packs on your '25 are bad. Why a SCSI bus problem causes the DMA error is beyond me! (or maybe the error isn't accurate!) -Mike
olson@anchor.esd.sgi.com (Dave Olson) (03/27/91)
In <9103261558.AA19295@euler.jsc.nasa.gov> johnson@EULER.JSC.NASA.GOV (Stan Johnson) writes: | We have an IRIS 4D-25S set up as a fileserver (running 3.3.1). We have an | intermittent problem reading tar files from cartridge tapes: the message | "WARNING: dma_map: address C055FFFF not word aligned" will display over | and over until the machine is reset. This is not at all repeatable, and | our field service person was not able to find any problems after running | all the diagnostics. This happens when you have cabling problems sometimes, so that a device sees a count incorrectly. It can also happen if you have an unsupported SCSI device that disconnects at any point in the transfer, rather than on a word (4 byte boundary). Due to a bug in the error handling code, it is never recovered from. It DOES recover from it in 4.0. In any case, it is extremely unlikely to be a memory problem. Check out your scsi devices, cables, and termination. | Another, possibly unrelated, error that I | haven't been able to track down is the message "NOTICE: plp/audio: | unexpected interrupt", Sounds like you are using a parallel printer. If the driver isn't expecting an interrupt, you get this message. It includes audio, because the same chip and interrupt are used for both audio and the parallel port. We do see this rarely on some of our print servers, and it usually is just a less than optimal cable. Nothing to worry about, unless it happens really frequently. -- Dave Olson Life would be so much easier if we could just look at the source code.