Subject: Re: Archive 4586NP woes
To: VaX#n8 <firstname.lastname@example.org>
From: Matthew Jacob <email@example.com>
Date: 07/23/1998 09:00:48
On Thu, 23 Jul 1998, VaX#n8 wrote:
> Tape Drive Questions:
> Drive: Archive/Python/Seagate 4586NP 4mm tape changer
> I have been noticing some strange behavior.
> First, the documentation I was given (in the form of some
> photocopied sheets) is rather lacking. In fact, the SCSI ID
> jumper settings were left-right reversed. This cost me quite
> a bit of time to figure out.
See seagate's web page. There's a pretty good PDF describing this
class of drive.
> After the drive writes to a tape, it won't respond
> to the Open/Close button (or the Step button, for that matter)
> until the tape has been ejected, even if the tape is rewound.
> Is this normal?
> On various occasions, I have witnessed the green "cassette" LED
> to blink slowly, or the amber "drive" LED to blink quickly.
> What do these mean?
Amber blinking can mean 'bad tape'
> Hardware or OS questions:
> Controller: based on NCR 53c810
> OS: a recent NetBSD (>= 1.3)
> Upon rewind, the drive retains exclusive access to the SCSI bus.
> I can think of three explanations:
> 1) The drive does not support disconnect/reconnect.
> 2) The controller does not support disconnect/reconnect.
> 3) The OS does not support disconnect/reconnect.
> Any guesses?
> Furthermore, if the "offline" command is given, and the drive
> does a long rewind, unload, reloads the next tape, and there
There's a jumper setting for this. See above.
> are significant accesses to the SCSI bus during this time,
> the machine does a hard reboot.
> Typical system logs are:
> ... ncr0: timeout ccb=0xf0874000 (skip)
> ... st1(ncr0:6:0): non-media hardware failure, data = 00 00 00 00 44 bc 00 3c 00 00
> ... st1(ncr0:6:0): not ready, data = 00 00 00 00 00 00 00 00 00 00
Compile with SCSIVERBOSE. It's there so that the data lines above
are decoded into something more useful.
> The timeout is by far the most frequent.
> OS question:
> I also had problems with the machine logging a line mentioning
> a timeout, and the CCB being dequeued. This frequently led to
> a hung SCSI bus. Thoughts?
Fix the above problems first. Mostly these drives are quite reliable.
Problems with them fall into these areas:
+ Jammed or slipping rollers for the cassette.
+ Generic DAT problem that once you write a media
pattern onto a DAT, you have to degauss it to get
a different media pattern, as well as other
tape class interoperability problems (e.g., a
DDS3 tape gives a DDS2 tape drive the fits).
This often leads to tape drive timeouts, etc...
+ Out of date f/w. Older f/w had problems. Check
with seagate or your distributor.