On 12/13/2011 05:03 PM, Henry Paul wrote: > Cooling might also be an issue. The Adaptec cards I have used with > passive cooling seem to require a great deal of airflow to remain > stable. Symptoms I have witnessed relating to overheating include > degraded I/O performance and in extreme cases kernel panics on the RAID > controller itself. > > HTH > > --Henry > Less common symptoms include headache, fatigue, dry mouth, nausea, paranoia, and in one case, acute megalomania. RAID should not be used in conjunction with MAOI, opioid medications, or flat RAID-0. Do not use single parity RAID with large stripe widths and large member drives manufactured in the Philippines. SERIOUS EFFECTS, INCLUDING MALIGNANT PUNCTURED STRIPES, HEART ATTACK, STROKE, AND SUDDEN DEATH, has occurred in many cases where RAID was used with COTS/OTC RAID cards and drives manufactured in the Philippines. While RAID can decrease your risk of sudden death and may improve your performance, RAID is not for everyone. Ask your vendor if RAID is right for you.
The cooling/heating bit dropping IO performance makes sense; it might be blocking to let the voice coils cool down, or doing repeated thermal calibrations to compensate for expansion. I've also seen videos of someone screaming into a Sun storage array while graphing it's IO, and the performance dropped significantly. My array service contractor told me that Sun has worked on noise sensitivity as well as mechanical vibration since then. I don't know if other vendors suffer the same problem, as I rarely shout at my Hitachis. My internal HP arrays on the other hand is another story. Grazie, ;-Daniel Fussell /* PLUG: http://plug.org, #utah on irc.freenode.net Unsubscribe: http://plug.org/mailman/options/plug Don't fear the penguin. */
