🚀 go-pugleaf

dsmith@mindspring.com (Don Smith) wrote:

>Question: What is different about the morning after I run a 
>tape backup? The problem happens even if I down the server, 
>and disconnect the tape drive after running the backup. 
>Could it be that either running the tape backup or downing 
>the server is causing Novell to compress a large betrieve 
>data file (4+ megs) which is from a very old version of 
>betrieve. Then the following morning, when someone uses that 
>file, something is causing the SCSI bus to hang?
>
>I realize I have to find the cause of the bus hanging. But I 
>am totally at a loss as to why the server will stay up fine, 
>apparently indefinitely, after it finally gets over its 
>problems, but will fail 100% of the time the morning after I 
>run a tape backup.
>

Welp... the place to begin is to take a look at your hardware 
- First check your termination. (remember 1st & last only!)
- If your tape unit is external try adding another external scsi device on the chain 
after the tape drive (like an old cdrom or tape unit) it may require active 
termination. 
- check to make shure that your SCSI tape drive is fully SCSI II compliant - many 
drives can't seem to handle the full throughput that the adaptec controller's are 
capable of (check the adaptecs configuration and if need be drop the tput form 10 to 
5)
- if you can use an isolated scsi controller for the dat (one other than what your 
HDs are on - you'll be better off)
- if your dat is SCSI ID# 3 or less change it to something higher (defacto is 4)

- looking back over your message I see you mentioned you also have a CD rom, will 
your tape drive run ok when the cd is not installed? (looaded or coonnected)  - you 
may want to look into updating your cdrom NLMs

- Do you have a second server available to run your backups from? 
- Do you have the dat always turned on?  external devices should be turned on before 
the server is booted and left on all the time until after the server is shutdown.
- If you run an attended backup does the server also lock?

The next is the obvious:
- try running the backup with as little loaded as possible, (start the server 
without the autoexec.ncf - just moount the volumes and try the backup - see if it 
does the same thing - you may have to rule out the NLMs one at a time
- check into cleaning the dat's heads.

just a few ramblings - goood luck!



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Just     {~._.~}    Andy McPhee
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