On Sunday February 1, keld@dkuug.dk wrote:
Why has nobody thought of it before? All descriptions I have seen of
RAID0+1 says that it needs 4 disks.
Just because it hasn't been implemented doesn't mean it hasn't been
thought of....
I started work on a "raid10" personality a while back, which could do
what you describe, or could stripe/mirror across 3 drives and other
combination.
It feel by the wayside as some things often do.
NeilBrown
On Mon, Feb 02, 2004 at 03:58:27PM +1100, Neil Brown wrote:
On Sunday February 1, keld@dkuug.dk wrote:
I started work on a "raid10" personality a while back, which could do
what you describe, or could stripe/mirror across 3 drives and other
combination.
Sounds like the RAID1E and RAID5E of some of the IBM ServeRAID controllers...
1E: Works across minimum of 3 drives, with the stripes written as:
Drive: 1 2 3
a b c
b c a
d e f
e f d
Ie. you still lose half the disk space, but will work over unequal
number of wrives with still a single drive failure resilience and a full
speed read.
5E: minimum 4drives, similar story just a tad different (No, I've mislaid
the documentation :()