[rescue] Sun Ultra 2 SCSI issues

[Ryan Thoryk]

> >From: "Ryan Thoryk" <ryan at tliquest.net>
> >To: rescue at sunhelp.org
> >Date: Sat, 24 May 2003 01:49:45 -0500
> >X-OriginatingIP: 192.168.0.6 (ryan)
> >Subject: [rescue] Sun Ultra 2 SCSI issues
> >
> >I've got a great Ultra 2 system (dual 250mhz, i love it), but weird stuff's
> >been going on with the SCSI bus that the cdrom's connected to.  I replaced
the
> >old cdrom drive it had with a much newer Yamaha cdrw 8x8x24 drive.  I also
> >tested the cabling, and it's fine too.  Now I know there's 2 scsi
connectors
> >on the motherboard, but for some reason the drive doesn't work on the left
> >one; only the right.
> >
> >The problem is that some cds will have enormous amounts of read errors (I
had
> >huge troubles installing Solaris 9), and the drive freezes up sometimes and
> >then slows down along with a bunch of head movements (both drives do the
same
> >thing).  I tested both drives on a Sparcstation 5 i've got, and they work
> >perfectly on there.  Everything else works perfectly on this system.
> 
> If it weren't for the fact they work on another system fine,
>  I'd say drive problems.
> 
> Not sure how SCSI termination is done in an Ultra 2, but maybe 
> you've got an unterminated end of the buss, or a double terminated 
> end, or some termination in the middle....

I'll check the termination, but it seems that I already tested that before.


> 
> >
> >Another question I have deals with a Linux server I run (pc x86 dual ppro
> >200).
> >It's got a pnp/non-pnp switchable 56k modem for dialins (i love that modem
so
> >much), and a nice large DSL line.  The modem is set to use COM3 with irq4
and
> >seems to be locking the whole system up usually after it hangs up the line,
> >seemingly only on external dialins, not dialouts.  I have an mgetty setup
> >along with pppd.  No messages can get dumped to the syslog because the
freeze
> >is more hardware related.  Has anyone experienced something like this
before?
> >
> 
> Is anything sharing IRQ4 (COM1 will use IRQ4 by default) ? 
> If COM1 is at IRQ4, is antything using it ? If you don't need 
> COM1 or COM2 and can disable them as to not exist, then my 
> standard suggestino would be disable COM2, and setup the modem 
> to be COM2.
> 
> Generally I hate IRQ sharing.... it is IMHO dangerous in the 
> least, and sometimes flat out doesn't work at all (even when 
> it "should").
> 
> Generally I'm also finding the more tidbits I learn about X86 
> architecture the more I hate it.  So many things about it just 
> make me quiver.  It is great to be able to still run DOS programs 
> from the 1980s (in theory anyway) but our modern computers 
> have some really ugly "hacks" to keep all of this backward 
> compatability... ick ick ick...
> 
> The last thing I read (in an Intel motherboard doc as I recall)
>  had to do with explaining PCI interrupts and how they get 
> mapped by some hardware to ISA IRQs (which we all know there 
> are not enough of).... an interesting thing was it could deap 
> with mapping the IRQs that way or another way
> (which sounded a bit better) under OS control.... gotta wonder 
> if PC Unixes (Linux, BSD, etc) do this, or if they just stick 
> with the PCI-> ISA IRQ mapping.... (for anyone interested the 
> manual was for the 440GX+ motherboard).

It's not the IRQ sharing, because I had both serial ports disabled in the BIOS
on that machine.  I have an external modem that works with it, but the modem
is defective lol (after about a minute of connection time the modem corrupts
communication and hangs up the line)

> 
> >Ryan Thoryk
> >Unix and Network Specialist
> >ryan at tliquest.net
> >_______________________________________________
> >rescue list - http://www.sunhelp.org/mailman/listinfo/rescue
> 
> -- Curt
> 
> Curtis Wilbar
> Hawk Mountain Networks
> rescue at hawkmountain.net
> 
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Ryan Thoryk
Unix and Network Specialist
ryan at tliquest.net