[asterisk-users] Re: Dell Server Question

[David Cook (Canada)]

Quoting "Nick Whitaker" <nickwhitaker at rfnow.com>:
> The problem I'm
> having
> is the only PCI slot shares an IRQ with the SATA controller.  Any
> altering of one device's IRQ takes the other device's IRQ with it in
> lockstep.
Nick, the word from Dell is that SC stands for "Simplified
Configuration" and there is less ability to move stuff around as you
wish. I too have a PowerEdge SC series (SC1400) which caused me some of
the same grief you are experiencing.

My basic understanding is that some of the PCI IRQ's are tied together
as there is less hardware/firmware support and is one reason the units
are so price competitive. Don't get me wrong. I love the box for it's
price/performance point and it has been rock solid for 5 yrs.

I fixed this by changing the linux kernel to include IO-APIC support
which permits the OS to route interrupts without overlapping IRQ's. I'm
assuming any reasonably new Dell hardware will support this and it comes
"on" by default in most SMP distributions.

You then get IRQ's ranging into the hundreds with no overlap. Note the
eth0, Cyclom-Y, 2 SCSI's & Sangoma which used to share in the old
scheme getting IRQ's into 3 digits.

# cat /proc/interrupts
           CPU0
  0: 2850398012    IO-APIC-edge  timer
  1:        952    IO-APIC-edge  i8042
  8:          1    IO-APIC-edge  rtc
  9:          0   IO-APIC-level  acpi
 11:          0   IO-APIC-level  ohci_hcd
 12:       3894    IO-APIC-edge  i8042
 14:   64252737    IO-APIC-edge  ide0
177:   52753938   IO-APIC-level  eth0
185:     260531   IO-APIC-level  Cyclom-Y
193:   25788929   IO-APIC-level  aic7xxx
201:         30   IO-APIC-level  aic7xxx
209: 2849304364   IO-APIC-level  wanpipe1
NMI:          0
LOC: 2850775576
ERR:          0
MIS:          0

dbc.
--
David Cook