[geeks] Cheap Dell Servers

Sridhar Ayengar ploopster at gmail.com
Thu Feb 7 13:49:10 CST 2008


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?

> 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?

Peace...  Sridhar



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