mjacob at feral.com
Tue May 7 08:23:35 PDT 2002
* From the T10 Reflector (t10 at t10.org), posted by:
* Matthew Jacob <mjacob at feral.com>
On Tue, 7 May 2002 jmasker at attotech.com wrote:
> * From the T10 Reflector (t10 at t10.org), posted by: * jmasker at attotech.com
> *** Rant mode on ***
> THANK YOU for asking this question. This has been a hot button with me
> for quite some time.
> To me it is always PAINFUL to watch a system boot with multiple SCSI
> adapters. Some adapter setup utilities don't even have the ability to
> change this parameter. Whenever I can, I always back this down to 64 ms
> and have never seen a problem.
> So to scan an empty bus takes almost 4 seconds. Add to this the stupid
> 3 SECOND bus reset delay and we're up to 7 ... PER CHANNEL. Now look at
> the fact that the BIOS driver comes up first and must scan all channels,
> typically one at a time, then the OS comes up and scans the channels one
> at a time, and we're at almost 30 seconds for a motherboard with a
> dual-channel SCSI built in.
> Granted, in the typical every day application environment, you aren't
> sitting there booting all the time. But in a test environment, I wonder
> just how many man-hours are lost waiting. *** Rant mode off ***
This is an absurd rant.
a) Fix your OS to not reset the bus
b) Use an adult system- not a toy with a broken BIOS.
c) 3.75 seconds is not unreasonable. If all busses done in parallel, what's
d) In either specialized production systems or test environments, shorten the
timeout as needed. The 250ms delay is a 'reasonable' amount of time for an
unknown target on an open back of system connection.
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