[clug] Update on Linux hardware RAID

[Darren Freeman]

List,

My new computer was ready for me to chuck Mandrake 9.1 on today. Oh
boy!!!

I am using an Adaptec 1200A hardware RAID card ($150), configured for
RAID 1 (mirroring two drives). Trying to make this the boot drive.

Linux sees it as two IDE channels as per a cheap IDE card. What I've
worked out is that it's a HPT370 chip and a BIOS chip. Windows would try
accessing the BIOS code and thus you get transparent software-RAID. Oh
boy a real hardware RAID for only $150!! Nope, just a couple of chips to
do what Linux does for free. Maybe the chip is accelerated in some way
though, but it presents itself to software as two IDE channels, you need
a software layer to make it look like one drive, and that's in the BIOS.

It's nice having a BIOS check the RAID at bootup and allow you to fix a
screwed system by mirroring to a new disc, but seriously I can use a
boot CD and dd if I want that.

In fact I can't boot from my system and I'm getting frustrated at not
seeing a single drive yet. It looks like I'm supposed to use the Linux
software RAID subsystem and request somehow that it talks via the BIOS
code to get compatibility across my dual-boot. It also seems to have
experimental replacement code for a HPT370 so I'll look in there and see
if it's really doing hardware acceleration of at least *something*. Else
a UDMA100 card would have been cheaper and sufficient. Screw Windows, I
don't care if it works with RAID, you have to reinstall often anyway so
just backup the data ;)

This link is enlightening for people unsatisfied with my ramblings:
http://www.mail-archive.com/redhat-list@redhat.com/msg120517.html

Darren