On 5/24/2013 1:32 AM, keld@keldix.com wrote:

On Thu, May 23, 2013 at 10:45:56PM -0500, Stan Hoeppner wrote:

quoted

On 5/23/2013 3:30 AM, keld@keldix.com wrote:

quoted

On Thu, May 23, 2013 at 12:59:39AM -0500, Stan Hoeppner wrote:

quoted

quoted

You may be tempted to use md/RAID10 of some layout
to optimize for writes, but you'd gain nothing, and you'd lose some
performance due to overhead.  The partitions you'll be using in this
case are so small that they easily fit in a single physical disk track,
thus no head movement is required to seek between sectors, only rotation
of the platter.

...

quoted

I think a raid10,far3 is a good choice for swap, then you will enjoy
RAID0-like reading speed. and good write speed (compared to raid6),
and a chance of live surviving if just one drive keeps functioning.

As I mention above, none of the md/RAID10 layouts will yield any added
performance benefit for swap partitions.  And I state the reason why.
If you think about this for a moment you should reach the same conclusion.

I think it is you who are not fully aquainted with Linux MD. Linux 
MD RAID10,far3 offers improved performance in single read, 

On most of today's systems, read performance is largely irrelevant WRT
swap performance.  However write performance is critical.  None of the
md/RAID10 layouts are going to increase write throughput over RAID1
pairs.  And all the mirrored RAIDs will be 2x slower than interleaved
swap across direct disk partitions.

-- 
Stan