MACSPECTRUM Posted June 5, 2003 Report Share Posted June 5, 2003 my client is having some problems with the server crashing at night backup runs at 2 a.m. - backs up ALL data (erases old data) each night on 1 tape for each day (i.e. Monday, Tuesday, Wednesday, Thursday, Friday - 5 tapes in total) tape mechanism is cleaned regularly as per notices from Retrospect software Retrospect 4.2 running on the server - max. of 300 MB AppleShare IP 6.3.3 G4/400 512 MB RAM Mac OS 9.2.2 backup device external SCSI DAT tape unit attached to internal SCSI card recently added RAID level 1 (mirror) 2 x 9 GB ultra-wide SCSI drives on their own SCSI card only 3 GB of 9 GB being used on HDs ony other application is 1st Class mail (30 MB max) server besides the appleshare ip 6.3.3 and the Mac OS 9.2.2 does anyone see any possible issues? is there an upgrade to 4.3? only the server is backed up directly to the DAT tape unit all users keep data on the server drives are regularly de-fragmented and optimized no viruses please feel free to email me directly at kulyk@macspectrum.com thanx in advance please ask any questions Link to comment Share on other sites More sharing options...
AmyJ Posted June 5, 2003 Report Share Posted June 5, 2003 Discerning Types of Freezes With a lock up on the backup Macintosh, you want to try moving the mouse to see if the ADB bus has locked up as well. If the mouse moves, but the Mac is hung up, it's most likely that your SCSI bus is hung, and you have a SCSI problem. If the mouse doesn't move, that means that the Mac's processor is hung, and you should look at System Software and extensions. More often than not, you will find that the mouse moves and you can force quit the program (at which point the Mac may or may not completely crash). A SCSI hang can be caused by one or more of the following: 1) a dirty tape drive or bad tape. Clean the drive. Try another tape. If other tapes work, then you just have a tape with a spot that's bad enough to crash your backup. 2) another device on your SCSI bus is interfering with the tape drive's communication. Make sure your SCSI ID numbers are set correctly. Turn off your Mac and the SCSI devices. Disconnect all SCSI devices except for the tape drive. 3) you have a bad cable. Replace the SCSI cable that connects the tape drive to the computer after removing other devices and cables from the SCSI chain. 4) you are missing a terminator or have a bad terminator. The last device and ONLY the last device in your SCSI chain needs to be terminated. Try replacing the terminator if you already have one on the chain. 5) the computer may be having a problem. Install Retrospect on another Macintosh and try the tape drive there as the lone SCSI device. 6) the drive may be defective. If you have implemented all of the preceding steps and get failures on multiple tapes after changing cables, terminators and computers, then the drive, being the only factor that has not changed, is the culprit--send it back to your vendor for repairs. The steps above are the essential outline of our SCSI troubleshooting here at Dantz. Hands on testing of device issues is really still the best method and even getting SCSI logging information is usually only to confirm empirical testing. Note that concluding something is a bad device is the LAST thing we assume after all other components and variables have been ruled out. "SCSI voodoo", as they call the nebulous symptoms that can plague a SCSI bus, can often lead one to false assumptions of the cause of problems. It's important that once a variable is tested that it be tested more than once for consistency's sake to rule out dumb luck. For example, SCSI voodoo accounts for why a tape drive may work fine for many months without proper termination but then suddenly fail in some way later. Although customers will often cite that nothing has changed with their SCSI bus configuration in months and that it was all working before, this is really a hallmark inconsistency of SCSI voodoo. The quickest and most conclusive test for most devices is to test it on more than one computer as the only device on the bus and with a different SCSI cable. If the problems can be reproduced on multiple computers, it's more than likely a hardware problem with the device itself. Of course there a myriad of other specific issues having to do with a device's own hardware settings like with internal jumper cables, dip switches or internal termination that has to be sorted out with the device's manual and/or vendor or manufacturer of the drive but the kernel of SCSI troubleshooting above is a good general guideline. Link to comment Share on other sites More sharing options...
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