[CentOS] software raid

[chrism at imntv.com]

Joshua Baker-LePain wrote:
>
> You know, the whole "disk is cheap, so why use RAID5?" argument just 
> doesn't wash with me.  Sure, disk *is* cheap.  But some of us need 
> every GB we can get for our money (well, given I'm spending grant 
> money, it's actually *your* money too (if you live in the US)).
>
> To demonstrate, let's look at a 24 drive system (3ware has a 24 port 
> 9650 board).  Newegg has 500GB WD RE2 drives for $160.  So for $3840 
> in drives I can get:
>
> a) 6TB RAID10 => $0.64/GB
>
> or
>
> b) 10.5TB RAID6 w/ hot spare => $0.37/GB
>
> Umm, I'll take 75% more space for the same money, TYVM.
>

c)  12TB RAID0 w/no redundancy =>  $0.32/GB

When my scratch data increases in importance, I'll have to investigate 
that new fangled RAID 6 thang.  :)  Does RAID6 suffer from this 
performance degradation bogey man when used with ext3?  Isn't RAID6 just 
RAID5 with a redundant parity stripe across the drives?

Cheers,