On Tue, Feb 18, 2003 at 10:23:01AM +0100, rb AT raphinou DOT com wrote:
> On Mon, Feb 17, 2003 at 05:51:16PM -0500, Joshua Baker-LePain wrote:
> > On Mon, 17 Feb 2003 at 11:27pm, marc.bigler AT day DOT com wrote
> > 
> > > I am using an Exabyte Eliant 820 tape drive on Linux kernel 2.4.18 and
> > > would like to make sure the hardware compression is disabled. Does anyone
> > > know how I can check that ?
> > 
> > For that drive, compression is controlled via density.  0x15 is 
> > uncompressed.
> > 
> 
> Isn't there a generic way of configuring it, like /dev/nst0 is the

Simple answer is NO, there is no generic way.

Case in point, my drive has internal dip switches that if I set them
in various configs will totally disable HW compression or will force
HW compression on with no ability to change it except reset the
switches and power cycle.

I have elected to set those switches to power up in no compression,
software selectable.  But another site might choose differently.

> non-rewinding device, isn't there a non compressing device? (I have the
> same question actually about being sure a Dell tape is in non
> compressing config, but I don't have the complete model details at hand....)

Some OS's do use different devices to select compression.  I do not think
those that use nst# and st# device names use that scheme.  Instead they have
software to set device properties, generally the mt command.  Again, no
generic solution there.

-- 
Jon H. LaBadie                  jon AT jgcomp DOT com
 JG Computing
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