Hello sun managers:
*****	My original post was:
> 
> 	I have a sparcstation20 with a tape unit and a external hard disk 
> connected to the bus SCSI (SCSI II). I want to add other hard disk, but 
> it has a old connector (SCSI I). Do you know of any problem (performance, 
> etc.) if i mix these different types of connectors? Can you give me any 
> reference about this topic?
>
        In general, there are a few problems with this type of implementation, 
it must operate normally. Bismark Espinoza recommend that i connect the 
SCSI I device to the end of the SCSI chain. I got only this reference in 
the WWW:
        Unfortunately, I haven't got the SCSI cable for test. :(  
*****	Thanks you to:
 
foster@bial1.ucsd.edu
Bismark Espinoza <bismark@alta.Jpl.Nasa.Gov>
Tariq Ahmed <tahmed@viper.istar.ca>
Jim Harmon <jharmon@telecnnct.com>
Jens Fischer <jefi@kat.ina.de>
Mariel Feder <unix.support@central.meralco.com.ph>
*****	These are the answers received:
foster@bial1.ucsd.edu wrote:
You might want to look at Celeste Stokeley's web page:
I don't think there are any performance hits when mixing these types
of connectors, but please don't quote me on that!
-------------------------------------------------------------------------------
Bismark Espinoza <bismark@alta.Jpl.Nasa.Gov> wrote:
It will work.
But you may get scsi errors.
Put the scsi-1 device at the end of the chain.
-------------------------------------------------------------------------------
Tariq Ahmed <tahmed@viper.istar.ca>
        As long as you have no SCSI ID conflicts, SCSI is downward
compatible. So you should have no problems.
-------------------------------------------------------------------------------
Jim Harmon <jharmon@telecnnct.com> wrote:
SCSI 1 is an 8-bit 10MB/s bus.
SCSI 2 is also 8-bit 10MB/s.
FAST SCSI2 is 8-bit 20MB/s.
If you have a fast-scsi system, you will slow your disk access about 25%.
If you have slow scsi already, you won't notice anything.
You should have NO bad problems.
-------------------------------------------------------------------------------
Jens Fischer <jefi@kat.ina.de> wrote:
the thing to look at is the disk, not the connectors. You can find many
SCSI II disks in enclosures with SCSI I connectors, which should be no 
problem
at all if you have a matching cable handy. The usage of SCSI I disks within
a SCSI II chain should also work as the SUNs are negotiating with every 
single
SCSI device in order to find a speed and transfer mode which is supported by
the device. As this works on a per device basis there should be no 
performance
impact for the SCSI II devices if you add a SCSI I device to the chain.
-------------------------------------------------------------------------------
Mariel Feder <unix.support@central.meralco.com.ph> wrote:
We have that working without any problem.
The only thing you need is a cable with each connector
on each end, and it should work transparently.
*****	Greetings!
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This archive was generated by hypermail 2.1.2 : Fri Sep 28 2001 - 23:11:58 CDT