🚀 go-pugleaf

In Article <824050290.7987@eurofinn.demon.co.uk>
thomas@highland.scotnet.co.uk (Thomas Woodrow) Wrote: 

> Does anyone out there agree with a policy of seperate SCSI cards for 
> each device? Could the clash have damaged any part of the machine 
> (thought to be very unlikely).

A lot depends on the requirements of your system or SCSI Subsystems
in general, personally I have had 3 SCSI HD's, 1 DAT drive, CDROM 
and a Scanner hanging off one card, no problems, sionce I started working 
in serious server enviroments I can see the reasoning behind it in _SOME_
cases, DAT's move data at around 512K per second on good ones,
CD's can do similar under burst rates, why tie up a bus with slow devices
when you can stick them on a single card....leave the fast stuff for HD's..

Scanning is slightly differant, it is unlikely that you will use much else 
when scanning because of the CPU usage of the scanning software.
However I suppose it is possible for the Polling to a CDROM drive
to interupt the flow of scanned data to the HD...

Having said that the CDR's are differant, when you write to one (or so
I have been told) you need to write your data in one continuous stream of
data stop for a second and you may be looking at a corrupted disk.

It is important to leave the machine alone with making your discs
and probably a good idea to have a seperate card with its own buffering
on it to fill any gaps you might get, some cards like the Adaptec seem to 
continually poll devices such as CDROMs, the light seems to flicker
every coupla seconds, I have seen this a few times with various systems,

My Dec Server 590 is no differant..

A recent server I installed had 4 SCSI cards installed, 2 embedded 
SCSI-2 FAST Adaptec controllers and 2 DPT controllers, no corruption
and no problems..

If you actually had both cards working it is unlikely that the crash or
data corruption was caused by them but SCSi cards can be funny
(or Not) beasts..

The hardest thing is to actually get them all working in the first place..
Since you had that I cant really offer an explaination for the corruption.

If you need any more info feel free to E-Mail me..

--------------------------------
- Steve Robertson, stever@mistral.co.uk, Worthing, UK
- 
- The opinions expressed are my own.
- (disclaimer)
- The above is still true, unless I decide to make up a
- fictional expert or guru, then the opinions belong to them.