>From the EXB-8505 SCSI Reference:

3.9 Handling unit attention conditions

The CTS creates a unit attention condition for each initiator when any
of the following conditions occurs:

*) The CTS is reset

*) The mode select parameters are changed.

*) A data cartridge is inserted and automatically loaded [the default].

...

The unit attention condition persists for each initiator until that
initiator issues any command other than INQUIRY(12h) or REQUEST SENSE(03h).

> Ken Wellsch wrote:
> > I see precisely this behavior on a NetBSD/i386 system (Pentium Pro)
> > with nearly -current (Jun 28 tar_file's) and an Exabyte 8700 series drive
> > (oh yeah, using an Adaptec 2940 controller).
> > 
> > ahc0: target 5 synchronous at 5.0MHz, offset = 0xb
> > st0 at scsibus0 targ 5 lun 0: <EXABYTE, EXB-8505, 0051> SCSI2 1/sequential removable
> > st0: drive empty
> > 
> > i.e. an "mt status" produces I/O error.  It does this when the drive has
> > the tape ejected and is open, and just loaded until it has gone through
> > all the wiz's and chug's then after a minute or two it will be okay. I've
> > also found that on some occasions, if left long enough (ten's of minutes
> > or hours? not sure) it *may* not do the I/O error but give a clean status. 
> > I've also seen that if I don't remember to do an "mt status" to "clear"
> > this potential problem it might impact my automated dump in the early AM.
> 
> If I try to access the drive when there is no tape, I get an I/O error
> and also :
> 
> 	st0(esp0:4:0): not ready, data = 00 02 00 00 00 23 00 00 00 00 c9 00 00 00 00 00 00 00 02 00 00
> 
> on the console.  This seems fair enough to me.  When I try with the tape in,
> I always wait until the tape has loaded (tape stops whirring, light stops
> flashing) and it consistently hiccups first time.  I've not tried leaving it
> more than a few minutes.  As for dumps, I do an 'mt stat' at the start of my
> dump script and just ignore the error.
> 
> I'll try leaving the drive alone for a while after loading a tape and see if
> that makes any difference - that would point to a problem with Exabytes.
> Does anyone see this with different types of tape?
> 
> J
> 


-- 
Juergen Hannken-Illjes - hannken@eis.cs.tu-bs.de - TU Braunschweig (Germany)