On Thursday, 30.08.2007 at 10:37 +0200, Goswin von Brederlow wrote: > > [RAID 6] > > If you write a single block then you have to read the 2 parity blocks > for the stripe, update them and write 3 blocks. So you have 5 times > the traffic on the bus. For anything doing single block writes this is > quite the killer. I would imagine a database like oracle to just die > with software raid6. *nods* I believe most database 'vendors' recommend RAID-10, and specifically to avoid any of the parity-based RAIDs, such as RAID-5 and RAID-6. Presumably for exactly the reasons you've outlined. For example, see http://edoceo.com/liber/db-postgresql-performance.php Dave. -- Dave Ewart davee@ceu.ox.ac.uk Computing Manager, Cancer Epidemiology Unit Cancer Research UK / Oxford University PGP: CC70 1883 BD92 E665 B840 118B 6E94 2CFD 694D E370 Get key from http://www.ceu.ox.ac.uk/~davee/davee-ceu-ox-ac-uk.asc N 51.7518, W 1.2016
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