[SunRescue] Proper use of VME scsi controllers?????

[Peter Koch]

Hi!

>The sun2 controller is ... probably not 100% SCSI compliant.
>It does work well enough for the 1/4" MT02 (SCSI->QIC36) interface and
>it makes a lot of sense to put tape drives on a separate bus from the
>disks they are likely to be used to backup, especially on older and
>slower SCSI subsystems.  Mixing disks and tape, especially on a sun2
>controller, will cause serious performance degradation.

Ah, much worse: If you rewind the tape, it BLOCKS the SCSI bus!!!
All attached disks will not be able to respond.

This is not a problem if you do backups overnight, but it will
hurt all users (the machine will sooner or later block all
processes, because paging doesn't work anymore) over daytime.
I prohibited the use of the tape drive for the normal users
then.

Tschuess

Peter