WangDAT 4mm tape usage questions

[Hans Dietrich]

In article <637 at brchh104.bnr.ca> dan at asihub.autosys.com (Dan O'Neill) writes:

>I am looking for information regarding the usage of a WangDAT drive on a
>Sun system.  We've been experimenting with the tape drive and have been
>experiencing back times like:
>
>4.7hrs to backup 500mb using dump with the following parameters
>"dump 5ubdfs 4096 488000 /dev/rst0 200 /filesys"

I had the same problem with the above mentioned configuration a while ago.
By default the WangDAT isn't among the st-devices which the kernel knows
about. So it uses some default values which are leading to the bad results
in backup time.

To get a fast backup you have to modify the file "st_conf.c" under
"/usr/kvm/sys/scsi/targets":

1. Search for the entry for the Exabyte 8mm cartridge

2. duplicate it

[ 3. change the comment (e.g. WangDAT 4mm cartridge) ]

4. change the line

		"Exabyte", 7, "EXABYTE", ST_TYPE_EXABYTE, 1024,
	   to
	   	"Wangdat", 7, "WangDAT", ST_TYPE_EXABYTE, 1024,

Now recompile the kernel, install it, reboot and have fun!

(The dump command I use is:
dump 0acbdfsu /etc/dumpfiles.1h0 126 27000 /dev/nrst1 6000 /dev/rsd1h)

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