[ale] disk i/o at 1,000 MB / sec, woohoo!

[Greg Freemyer]

I needed to wipe a 1.5 TB Raid 5 array on a demo unit today before returning it.

My expectation was a few hours or more to do it.

I booted up a linux boot cd and started dd  (actually a customized
version known as dcfldd.  It's my own custom boot CD.).

Its running about 1 GB/sec or 1,000 MB/sec.

My wipe of 1.5 TB should finish in less than 30 minutes.

Even if you consider there are 6 drives in the array and divide the
throughput by 5, that's still 200MB / sec / drive.

That is the fastest I've seen yet!  Requires both extremely fast
drives and an extremely fast raid controller.

I normally work / test SATA drives.  A really fast sata is about half
that speed.  I haven't tested hardware raid performance recently, so I
don't know how unusual a 1,000 MB/sec aggregate throughput is.

fyi: 15K rpm SAS drives in a modern Dell 2U unit (PowerEdge R710).

Greg