And assuming that "c" does enable compression on your solaris
system the difference (at least on my drives) between "h" and "u"
is also the HW compression, though both are highest density 
(on devices where its offered).

On Mon, Feb 07, 2005 at 10:48:27PM -0500, Jon LaBadie wrote:
> On Mon, Feb 07, 2005 at 10:06:09PM -0500, Gene Heskett wrote:
> > On Monday 07 February 2005 18:31, Paul Bijnens wrote:
> > >Gil Naveh wrote:
> > >> Gene - thanks for trying to help,
> > >>
> > >> Currently the only reason that I can think of is that Amanda has
> > >> not read correctly our tape drive so I am re-running
> > >> #amtapetype -f /dev/rmt/0n
> > >
> > >Add an estimate value!  And it takes about 5 hours only. Without
> > >an estimate it takes a week or so.  Like this:
> > >
> > >   amtapetype -f /dev/rmt/0n -e 200g
> > >
> > >On the other hand, writing a few bytes is enough to see it the drive
> > >works.
> > >
> > >About the problem: you did specify that device in your amanda.conf ?
> > >(I believe that was what Gene was hinting about.)
> > 
> > Chuckle, yup.  Sometimes I get my tongue tangled up with my eyeteeth, 
> > and can't see what I'm writing...  Corrections in that case are 
> > always welcome. :-)
> 
> With the ultrium it is less important about considering HW or SW
> compression.  But be aware that on Solaris whether HW compression
> is turned on or not is determined by the device you choose.  You
> will find lots of /dev/rmt/0"xyz" devices.  The "xyz" determines
> the properties of the device the driver will set upon opening it.
> 
> Don't be fooled into assumptions about the various devices.  The
> "c" device is listed as "compressed".  But that is the conventional
> use.  There is no certainty that it turns compression on for every
> device, or that devices without the "c" are no compression.  You
> will even have a "c" device for drives that are not capable of
> HW compression ;-)  Only way to tell is check the docs for the
> drive and settings for the driver.  And then I'd check it if I
> could.
> 
> -- 
> Jon H. LaBadie                  jon AT jgcomp DOT com
>  JG Computing
>  4455 Province Line Road        (609) 252-0159
>  Princeton, NJ  08540-4322      (609) 683-7220 (fax)
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