Re: raid1 on ide decreases read performance

[D. Lance Robinson]

Osma,

RAID-1 does read balancing which may(?) be better than striping. Each
read request is checked against the previous request, if it is
contiguious with the previous request, it uses the same device,
otherwise it switches to the next mirror. This process cycles through
the mirrors (n-way mirrors.)

The bottom line: Read performance for a RAID-1 device is better than a
single (JBOD) device. The bigger the n in n-way mirroring gives better
read performance, but slightly worse write performance.

<>< Lance.

Osma Ahvenlampi wrote:
> 
> Dietmar Stein <[EMAIL PROTECTED]> writes:
> > Readperformance will only increase by using raid0 (stripe), but it will
> > not be twice times faster.
> 
> Does the Linux RAID-1 code still not stripe reads? I thought it did.
> 
> --
> Osma Ahvenlampi