SUMMARY: Dump parameters for a 4mm DAT drive (not solved)

From: Ernie Cisneros (
Date: Fri Aug 21 1992 - 18:23:49 CDT


Thanks to those that sent a reply to my orignal question. Part of my
problem was the enability to get two large (> 100 Mb) disk partitions
onto a single dump tape. The first was written to tape OK, but
the second was partitally done when dump simply ran out of tape and
reported a tape error. The dump parameters were density=27000,
size=6000, blocking factor=126. I'm still not able to get 1.2 Gb worth
of data onto the tape. I've been experimenting with the parameters given
below, hoping to hit upon the magic numbers. I'll forward those results
when I get some concrete numbers.

                                Ernest Cisneros
System Administrator System Administrator & Manager
Northern Arizona University United States Geological Survey
Geology Department Astro-Geology Branch
P.O. Box 6030 2255 N. Gemini Dr.
Flagstaff, AZ 86011-6030 Flagstaff, AZ 86001
Phone: 602/523-4384 Phone: 602/556-7022
                                Fax: 602/556-7014

Responses Given by Sun-Managers
>From Mon Aug 10 13:05:33 1992

I'm using /usr/etc/dump 1cusbdf 250 800 610000 /dev/nrst1 /dev/rsd3h
to talk to the wangdat model 2000 SE jumpered for compression, and get the 5.2 G.

Jeff Marans.
>From Mon Aug 10 17:21:01 1992

We use a WangDAT from R^2 under 4.1.2; we had to modify the standard
Sun SCSI configuration to use the drive properly; you might be using
R-squared's device driver (which I don't recommend.) Let me know if
you'd like the changes to the configuration file.

We use the following for dumps. I've no idea if they're optimal, but
they seem to work OK.


dump 0cbdsf $BLOCKSIZE $DENSITY $SIZE $ARCHIVE /dev/sd0h ...

        Mike Caplinger, MSSS/Caltech Mars Observer Camera Project,
>From Tue Aug 11 00:41:42 1992

Hi Ernest,

We use a SONY DAT (SDT 1000) with the following dump parameters:

        dump 0ubvfs 126 /dev/rst0 70000 /dev/rdisk

Good Luck..

>From Wed Aug 12 05:57:59 1992

I have two 4mm DAT drives both are HP brand. The first one is
a HP-35450A 1.2GB. For dumps I use 15000 for density, 10000 for
size and 100 for blocking factor. The second is a 2.0GB and I
use 15000 density, 15000 size, 100 blocking. I get the max data
storage from this setup.

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