>Date: Sun, 21 Apr 2002 18:31:59 +0200 >From: Johannes Gebauer <[EMAIL PROTECTED]> > [context] >In my SCSI chain I have a Syquest EZ, a HD, a CD burner and a Scanner. So >far I have always shut down the computer to switch any device on or off. In >addition I always have the scanner on (when it is connected; I am on a >laptop, so I don't always have my SCSI chain connected), because it is the >last device in the chain and is terminated internally [segue with comments] >1) Should the scanner always be on, or will the termination work with it >off?
Try it and ask SCSI Probe what it thinks of the SCSI chain. Trying it once won't hurt. If your computer doesn't boot, then you'll know. NB: If your computer didn't boot, it isn't very likely to write anything to a disk, right? Ergo: no damage should be done. Note, however, where I carefully use the subjunctive. More below. >2) If it doesn't need to be on, can I freely switch it on or off when it is >not in use, or can I just switch it on while the computer is running but not >off? > >3) From what you are saying I understand I can switch the other devices on >while the computer is running. Can I also switch them off (obviously after >unmounting any media in them) while the computer is running? With a PB, be careful about changing state of the SCSI chain when the computer is asleep. Don't turn the scanner off if software is using it (PhotoShop or whatever). In general, turning devices off is trickier than turning them on: Once something has been turned on, it is hard to know for sure if some piece of software (OS or app level) has noticed the device and is blithely assuming the device will remain available forever. Turning the device off at this stage is likely to cause annoyance. >4) Is there any risk of Data loss, or damage when doing any of this? SCSI is a very black art. Much depends upon implementation details--both in hardware and in firmware. Sometimes things may even depend upon the cables you use (though anomalies here generally point to a dud cable). Basically, my advice is to ask SCSI Probe (or similar) to look at the SCSI chain with whatever non-textbook configuration you want to use. If the profiling software is happy, than you're probably safe. You're doing regular backups anyway, right? So you can keep an eye on your disks and data and react promptly if Something Bad(tm) happens. You can do lots of non-textbook things with SCSI and live to tell the tale. The main thing is to watch what you're doing. Oh, BTW: no warranties, no gaurantees. Advice is given in good faith and based on my experience, but that's all. Cheers, PEter --------------- <http://www.bek.no/~pcastine/Litter/> --------------- Peter Castine | From the Litter Power Thesaurus: [EMAIL PROTECTED] | Limiting to range: [EMAIL PROTECTED] | lp.scampf, lp.scampi, lp.scamp~ _______________________________________________ Finale mailing list [EMAIL PROTECTED] http://mail.shsu.edu/mailman/listinfo/finale
