On Tue, 12 Sep 2000, Mohler, Anissa wrote:
Bruce is right... the quote as outlined in the e-mail below is incorrect. The exact quote from the Advanced Administration and Troubleshooting "202" Student Guide Dated April 2000 (Page 8 of the performance tuning section) is:
"There is an approximate 10% decrease in write performance when the filer attempts to write to a RAID group spanning two adapters. This is due to inherent limitations in the PCI bus."
Page 41 of the Performance Tuning Section does not specifically say WRITE performance but page 47 does. I'm sure this issue will be addressed in the next version of the course.
I picked my quote from the same version, Chapter "Health and Performance," page 9. That too will need an edit.
Thanks for the clarification, Anissa.
And, as Bruce indicated, I often run into the cp-to-cp consistency points, so I would be affected by this 10% degradation if I had a fractured RAID group. I probably incorrectly assumed the person asking the question was concerned about performance at the top-end, also, where this 10% may have been helpful. Mea culpa.
Until next time...
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