[Tfug] Crappy USB LVM/Software RAID10 performance?

[Tom Rini]

On Fri, May 29, 2009 at 10:31:22AM -0700, Bowie J. Poag wrote:

> Striping, by itself, only requires two drives minimum. Thats what RAID0
> is. A striped data set. <br>
> Mirroring that data set will require 2 more drives, making 4 drives
> total. Thats what RAID 0+1 is. A mirrored, striped data set.<br>
> Mirroring, by itself, only requires two drives. Thats what RAID1 is. A
> mirrored data set.<br>
> Two drives in a mirrored relationship can also be in a striped
> relationship. Thats whats RAID10 is. A striped, mirrored data set.<br>

But, um, that requires 4 partitions then, right?  D1P1 / D2P2 (mirror)
and D1P2 / D2P1 (mirror) and then stripe those together.  Right?  If so,
does this really provide more saftey over just doing a RAID1 on the two
drives?  Might this overhead not be adding to the slowness you're
seeing?

-- 
Tom Rini