On Tue, Mar 11, 2003 at 09:19:11AM -0500, Eric Sproul wrote:
>
> > >BTW, the drive has no DIP switches for setting compression--
> >
> > That would definitely be unusual... The lawyers have attacked the
>
> This is a Compaq SDLT320 drive. According to the reference guide:
>
> "The SDLT drive ships from the factory with data compression enabled for
> writing. In this mode, data is always compressed when writing to the
> tape, but the drive is capable of reading both compressed and native
> tapes. For the drive to write native data, the data compression setting
> must be changed through the software. To change the setting, consult
> the backup application software documentation for the data compression
> enabling and disabling procedure."
>
> Believe it or not, it's software-only. From a visual inspection of the
> library, the part of the drive visible from the rear has no switches.
Eric,
For my drive, an HP DDS3, the same statement "could have" been included.
I.e. as shipped it is HW compression enabled. SW control is necessary
for it to write native.
And guess what, it has no rear switches.
However, the HP manual shows that if you "remove" the drive, that a
switch set exists on the bottom of the drive.
Again, on the HP, one of those switches controls what mode the drive
comes up in at power on. And the drive is shipped with it set to
HW compression mode as a statement like yours suggests. But flip the
switch and it comes up in native mode.
A second switch controls whether the power up mode is locked or if it
can be changed under software control. My HP drive ships with SW
control enabled, just as the Compaq statement says.
My point being, not that your drive is like mine, just that nothing
you have written/discovered rules out the existance of switch settings.
OTOH, you know it comes up in HW compression mode and that you can
change it under SW control and that is suitable for you. Maybe
further exploration is non-productive.
--
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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