Re raid SW vs HW , was Okay, this is so not cool..

Xose Vazquez Perez xose at wanadoo.es
Thu Oct 16 13:49:01 CDT 2003


Matt Clark wrote:

> No doubt all true if you don't have battery backed cache.  
> With BB cache writes are almost instantaneous, and no amount of CPU can
> give you that.
> 
> Also don't forget that HW RAID does use special hardware for parity
> calculations etc, and may well give you many more channels to
> work with.  But again, it's the write-back cache that gives you the big win.
> 
> And one more thing, if you do RAID on IDE drives for data safety, you 
> *must* turn off the write caching on the _drive_.

Linux SW raid + aic79xx(Adaptec Ultra320) + RAM enough + UPS, are cheaper
and faster than any decent board raid.

IDE bus for RAID is a toy.
-- 
Software is like sex, it's better when it's bug free.




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