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Date: Mon, 3 Mar 1997 17:39:32 -0800 (PST)
From: Doug White <dwhite@gdi.uoregon.edu>
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Reply-To: Doug White <dwhite@resnet.uoregon.edu>
To: Tom Bartol <bartol@salk.edu>
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Subject: Re: Density codes for Exabyte 8505XL
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On Mon, 3 Mar 1997, Tom Bartol wrote:

> But the modes listed here don't really correspond what I'd expect to see
> for a helical scanning tape drive.  I have been able to use density
> mode X3.202-1991 (hex code 0x14) but I don't whether is the the max
> density code for my drive and I don't know what other codes might be
> available.  Codes 0x13 and 0x15 (which are listed at helical scan density
> codes in the mt manpage) don't work on my drive.

The dump density/length options don't apply to newer drives very well. 
Instead, use the B and b options, which specify # blocks and blocksize in
kilobytes respectively.  We have a Connor 2gb drive and use the following
dump commands to make backups over a network. 

rdump 0uBbf 2000000 10 resnet2.uoregon.edu:/dev/nrst0 /
rdump 0uBbf 2000000 10 resnet2.uoregon.edu:/dev/nrst0 /var
rdump 0uBbf 2000000 10 resnet2.uoregon.edu:/dev/nrst0 /usr
rdump 0uBbf 2000000 10 resnet2.uoregon.edu:/dev/rst0 /usr1

Tune to meet your needs.  Excessive shoeshining (back,forth,back,forth)
can be solved by adjusting the blocksize.  

Hope this helps.  See dump(8) for further details.
 
Doug White                              | University of Oregon  
Internet:  dwhite@resnet.uoregon.edu    | Residence Networking Assistant
http://gladstone.uoregon.edu/~dwhite    | Computer Science Major