swithing on/off compression in seagate/cetance dds3 SCSI i..

Archived from groups: comp.sys.ibm.pc.hardware.storage (More info?)

arctan wrote:

> Hello Group
>
> I have a question that hopefully could be addressed here.
>
> I have a Certance/Seagate DDS3 SCSI Python external DAT drive for
> Windows 2000/XP/2003.
>
> I want to tun off compression. it is 12/24. I am not sure if I trust
> compression.
>
> But I am not able to access any windows in the winOS that allow me to
> do this. In device manager, all pull down menus that would enable me
> to do this are greyed out. This should not be a permission issue.
>
> I have looked in the driver files for fields that I could edit to turn
> off compression, and have not found any.
>
> I have driver files stdatw2k.inf and others of this type. Is there
> something I need to edit in one of these files that is not obvious?
> (i.e. I have not found any line in the config files that says
> something along the lines of "compression=on")
>
> hopefully this could be a usefull thread to have in the archives of
> this group if anyone knows how to deal with this. Thanks in advance
> for any help on this issue.

RTFM. Compression on tape drives is hardware--you turn it off with a switch
or jumper on the drive. The instruction manual for your drive (you can
download it from the Certance site) tells you where the switch is located.
You'll have to open the enclosure.

The jumper setting can be overridden by a SCSI command however it's rare to
encounter software of any kind that supports this particular capability.

Regardless, there's no reason to do this unless you're routinely working
with datasets that have already been compressed.

I've never heard of any kind of data corruption being caused by the
compression algorithms which tape drives use.

> mechuniversal

--
--John
Reply to jclarke at ae tee tee global dot net
(was jclarke at eye bee em dot net)

Archived from groups: comp.sys.ibm.pc.hardware.storage (More info?)

arctan@moonman.com (arctan) wrote in news:c6d76a1b.0410232325.33fe3294@posting.google.com:

> I have a Certance/Seagate DDS3 SCSI Python external DAT drive for
> Windows 2000/XP/2003.
>
> I want to tun off compression. it is 12/24. I am not sure if I trust
> compression.
>
> But I am not able to access any windows in the winOS that allow me to
> do this. In device manager, all pull down menus that would enable me
> to do this are greyed out. This should not be a permission issue.

I'm not sure if this drive allows turning off compression by software. More likely
the drive has some jumpers on it that allow you to set compression. This is the case
with my Seagate Scorpion DDS4.

--
Toomas Aas