[CentOS] 4 X 500 gb drives - best software raid config for a backup server?

[Ian Forde]

On Wed, 2009-02-18 at 08:13 -0800, dnk wrote:
> On 18-Feb-09, at 2:01 AM, John Doe wrote:
> 
> >>> For controller, what is the interface on your drives??  SCSI, SAS??
> >> Dell 2950, SAS 6 Host Bus Controller.
> >
> > Integrated SAS 6/i(base): 4 port SAS controller (does support RAID  
> > 0/1)
> > But I don't know if that is descent hw raid or crap raid...
> >
> > JD
> 
> This was kind of the reason I was thinking software raid.
> 
> Has anyone had any raid experience with this card?

Yep - it's real HW raid, though with a 2950, I would have gone for the
PERC instead.  The integrated SAS is usually a Fusion-MPT (LSI/Symbios)
card.  Do a 'lspci' to be sure.  I've got a few of these configured and
I can check the raid status with the mpt-status command (from the
mpt-status rpm).  Note that doing a 'fdisk -l' only yields one disk when
RAID is setup.  So yes - it's real HW raid.  Just not much in the way of
cache, which is why I prefer using PERCs instead...

	-I