RAID controller question...

[Greg Lindahl]

> the question is whether your Beowulf machine really needs to sustain
> well over 20 MB/s, since it can do that on its builtin UDMA controllers.
> if your needs are specialized (massive bandwidth, >68G/node, etc),
> then you're getting out of the "leverage zone", and into a niche.

As usual, generalizations lead you astray. If you want to hook 10+
drives to a machine and are seek limited, UIDE won't do it for you,
even if your sustained bandwidth is much lower than 20 MB/s. Think
database. Sure, that means you spend more money.

No one has advocated choosing the wrong hardware for a given
situation. Yet we've had much heat and and little light in this
disucssion, and many assumptions that your environment and needs are
everyone else's.

BTW, in reference to Alan Cox's comment a while back, I don't think
that the Linux md drivers have the right stuff for scsi hotswap. It's
a matter of both hardware and software. I'd love to be wrong about it.

-- g