SUMMARY: (Addendum) DDS-2 Tape Drives on SPARCstation-5 with SunOS 5.5

Srinivas Maddhi (smaddhi@ccad.uiowa.edu)
Tue, 17 Feb 1998 16:57:44 -0600

On 16 Feb 1998 20:17:58 -0600 Srinivas Maddhi <smaddhi@ccad.uiowa.edu>
wrote:

> On 29 Jan 1998 21:46:42 -0600 Srinivas Maddhi <smaddhi@ccad.uiowa.edu>
> wrote:
>
> > I need help determining if it is feasible to go from an existing
> > Python 4mm DDS-1 tape drive to a DDS-2 tape drive on the hardware and
> > OS combination: SunOS foo 5.5 Generic sun4m sparc SUNW,SPARCstation-5.
>
> We chose the HP C1599A mechanism.
>
> I was able to get approximately 1100 KB/s of throughput with the either
> of the two DIP switch settings mentioned above when the drive was
> connected to the second SCSI bus on an SS5 as the sole device on that
> bus.

These transfer rates were obtained using the compression device
(/dev/rmt/0c*). I was able to pack close to 7 GB onto the tape.

Transfer rates between 500 to 700 KB/s were obtained when not using the
compression device.

> Connecting it to an SS5 with only one SCSI bus and having four other
> devices attached to that bus drops the transfer rate to ~ 700 KB/s.

In this case it doesn't seem to matter what device I use -- I get
approximately the same transfer rates and capacity using any of
"/dev/rmt/{0,0m,0c}" (strange). Am able to pack approximately 6 GB to
tape (strange).

The transfer rates are as reported by 'ufsdump' (I probably should hand
check these). The capacities reported are also the result of dumping
filesystems to tape using 'ufsdump'.

-- 
Srinivas Maddhi
(319)384.0572/358.4084P
CCAD Computing Services