[PlanetCCRMA] RAID questions...kernel patch?

Aaron Trumm aaron@nquit.com
Thu May 19 09:15:03 2005


hmmmmmmmmmmmmmmmmmmmmmm - thanks :)  

hmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmm

> The kernel does not have anything extra (in terms of outside patches)
> and I don't know which hardware raid devices it may support. Most of the
> mobo level raid devices are just software raid, they need a special
> driver on windows (which, surprise, does the raid thing :-) But again, I
> don't know which ones may be exceptions to that rule. 
> 
> When I set up raid (raid5) on my servers I ended up using software raid
> after all. I have multiple disk (expensive) sata cards that can do
> hardware raid but that ended up being slower than using a properly
> configured software raid5 solution - I imagine that the limited amount
> of onboard cache of the controller works against raid5 performance when
> you compare it to using the whole memory space of a linux system as a
> cache for writing (again, I have only tried raid5, not raid0 or raid1). 
> 
> Another advantage of software raid is that you could move the drives to
> a completely different motherboard and controller and they will still be
> recognized and used as a raid array. Most probably that is not true of
> hardware raid, you are locked to the internal format that that
> particular controller uses. 
> 
> -- Fernando
> 
> 
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