[geeks] Cheap Dell Servers

[Sridhar Ayengar]

Sandwich Maker wrote:
> " > " One thing I'm still trying to work out is how to set the disklabel drive 
> " > " parameters for a RAID.  What is the RPM of a RAID?  How does one 
> " > " determine a physical sector count for a virtual disk?
> " > 
> " > for a simple stripe it should be easy.  rpm is rpm of individual
> " > disks; sector count is sc/disk * num of disks, since that's the
> " > latency of the stripe.  for a raid-5 it's not so simple, never mind
> " > the complications of sw vs. hw raid.
> " 
> " It's RAID 5, so it should be mostly similar to that, no?
> 
> yeah, that makes sense now that i think about it.  raid parity is
> distributed, right?

Yes, indeed.

> " > but if your software and your drives support tagged command queueing
> " > it's probably all moot.  the driver doesn't have to do any elevator
> " > sorting; the drives do it.
> " 
> " There's NCQ on the drives.  I'll have to see if the RAID controllers 
> " support it.  If so, I would assume I don't have to have any particular 
> " settings in my disklabels for optimization?
> 
> not for drive access.  the fs frag issue you raise has me wondering
> though.

I'm getting more confused as time goes on...

Peace...  Sridhar