Also Sprach Joi Ellis:
> Well, one thing I learned is if your device is an UltraWide, and your
> interface card is a slow-narrow, you'll have to buy expensive adapters
> and cables to connect them together. The costs of these additional
> items and the instability they can add to your system (ie in time
> debugging the scsi chain, having the connectors fall off the back of the
> card due to the extra weight, etc) can drive your costss beyond what
> the UltraWide card would have cost you in the first place.
>
Just another data point:
Here is one of my backup server's dmesg:
Vendor: HP Model: C1537A Rev: L706
Type: Sequential-Access ANSI SCSI revision: 02
Vendor: HP Model: C1537A Rev: L708
Type: Sequential-Access ANSI SCSI revision: 02
Vendor: HP Model: C1537A Rev: L610
Type: Sequential-Access ANSI SCSI revision: 02
Vendor: ECRIX Model: VXA-1 Rev: 2524
Type: Sequential-Access ANSI SCSI revision: 02
Vendor: ECRIX Model: VXA-1 Rev: 2959
Type: Sequential-Access ANSI SCSI
revision: 02
The 1537As are narrow, the Ecrix Wide LVD, the controller an Advansys
fast narrow. The drives are external, the cabling is kept short: from
controller to the first drive 1 meter, the rest 0.5 meter for
a total external length of 3 m. The narrow drives are connected
first, then a 50 to 68 pin cable with termination of the 18 pins connects
the wide drives. A multimode terminator is at the end of the chain.
I haven't had any SCSI errors in this configuration. I believe
that the configuration does not violate the SCSI cabling and
termination standards but I do admit I am surprised that it
works w/o incident. I have done backups on one drive and restores
from others at the same time w/o hanging the SCSI bus.
The difference in cost between narrow and wide controllers is about
$20, the same as for a 50 to 68 pin adapter, so I agree that
getting a Wide card with a DDS4 drive is a good idea. In fact even
if one buys DDS3 drive I'd go with the Wide controller and an
adapter since going from Wide to Narrow is less hazardous than
Narrow to Wide, and the likelihood is that you'll junk the
DDS3 drives in a year for a larger capacity drive, and all those
now come in SCSI Wide.
--
C. Chan < [EMAIL PROTECTED] >
Finger [EMAIL PROTECTED] for PGP public key.
