Re: Serial Console and Slow SCSI Disk Access?

[Mark Lord]

Jeff Gold wrote:
> Does it make sense that enabling a serial console would reduce the 
> bandwidth of a SCSI disk by more than a factor of ten?  This seems crazy 
> to me but there's no arguing with empirical facts.  I have an IBM x345 
> system on which I installed an unmodified 2.6.16.20 kernel built with 
> gcc-4.0.2-8.fc4 (the kernel configuration file I used can be found at 
> http://augart.com/jgold/kconfig).  With the control kernel command line 
> I get about 70 MB/sec with hdparm -t but when I add "console=ttyS0,9600 
> console=tty0" I get about 1.6 MB/sec instead.

This can happen if there are kernel messages being printed on the serial console.
If all is quiet, I would expect things to be as fast as normal elsewhere.

-ml
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