🚀 go-pugleaf

In article <1992Dec28.110145.11642@mic.ucla.edu> iwelch@agsm.ucla.edu (Ivo  
Welch) writes:
> After  my  twentieth problem with   connecting/disconnecting SCSI disk
> drives, I am   wondering   about  the proper "protocol"  of   handling
> connecting/disconnecting/transporting them.
> 
> 	[1] I understand that first the host should be synced and halted.
> 	Question: Does the host also need to be powered down, or is the
> 	ROM Monitor sufficient.
> 
> (then)	[2] Should the hard disk be powered down before it is removed
> 	from the SCSI chain, or can I unplug it from the SCSI chain with
> 	power on?
> 
> (then)	[3] Is it safer to move the hard disk with power on or with  
power
> 	off? A repair man once told me that the air pressure from a running
> 	disk is a better warranty that the head won't touch the disk.
> 
> Oh, I own an Imprimis 94601-15 and a Seagate ST41650 disk.
> 
> /ivo

Well, I can tell you that our hardware guy would wince at the very
thought of doing anything without a complete power down of external
drive and machine.  Then power up drive, then machine.  
-Bill
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                           5000 H.P. Track Staightener

Summary:    [1]  Although  a number of   people  suggested powering down,  Sam
Goldberger told me that the  SCSI bus is silent in  the ROM monitor. (Powering
down is actually  inconvenient   for me,  because I  have    auto-startup set;
unfortunately, NeXT software does not distinguish between a controlled power
down and a pull-plug power down, and always restarts itself.)

[2]  Everyone suggested I should power  down  hard-disks first;  for one, they
set or signal their SCSI ID at power on.

[3]  Everyone  suggested powering down hard  disks before moving them, because
most disks have special head storage zones.

Thanks to everyone.

/ivo