Software RAID 5 or something else?

[Patrick O'Callaghan]

On Fri, 2009-01-23 at 14:53 -0600, Seann Clark wrote:
>  The biggest advantage with hardware RAID is you don't need to boot to
> be 
> able to fix your RAID. Minor difference for some of your more
> hardcore 
> computer guys, and rather trivial, but it is nice to see your RAID is 
> shattered prior to the kernel barfing on you. Once again, I am sure
> one 
> of our Software RAID guys will tell me what really happens if the
> raid 
> is dead to the kernel in a software config.  The other thing I have
> yet 
> to see is software raid being hot swappable. This is nice because if
> you 
> are doing more than using the system as a gaming, or personal server, 
> you don't have to power down, replace, reboot, rebuild. I don't know, 
> maybe I am just lazy.

Something that often seems to be forgotten in these discussions is the
impact on your system response when a RAID structure is being rebuilt
after a hot or cold swap. This can take hours (during which time you're
still vulnerable of course) and may slow the system considerably. You
need to dimension accordingly.

poc