[clue-tech] Software RAID

[Russell Glissmann]

I'm looking for someone who might have already run into issues with
software RAID from CentOS 4 (or RHEL 4).  As a background, I'm testing
this inside a VMware enviroment where I'm using two SCSI drives, each
roughly 4G.  When installing I use the Disk Druid to partition the
drives into two identical sets (sda1: 100M, sda2: 500M, sda3:
remainder size).  Then I create a raid device for each (md0: /boot,
md1: swap, md3 /).  The install goes on its merry way using Grub as
the boot manager.  On restart everything boots up just fine.  If I
fail a drive using mdadm --set-faulty (md0/1/2, sda1,2,3), again the
system will reboot just fine.  Just for kicks I removed the sdb drive,
not via software but by "removing" the drive from VMware.  Again the
system boots just fine.  YEA!  However, just for kicks, I removed the
sda drive, again "removed" via VMware, and now the system won't boot. 
If I use the rescue mode I can mount the drives, and everything is
where it should be.  If I add a new sda drive, again the system won't
boot.  Again if I use the rescue mode, I can add the drives to the
array and resync the array no problem.  However, again if I try to
reboot, the system will just hang.
Aparently from experimentation, and from a couple of CentOS threads,
it appears that Grub is actually only installing itself on the sda
drive, but not the sdb drive.  With this thought in mind I have
attempted to install Grub onto the sdb drive.  Now what I get is just
the grub prompt, no boot.  Grub sees the boot directory, and the
stage2, but for some reason will not boot to them.
I have tried pretty much everything I can think of, with no luck.  So,
I am looking for suggestions.  The only thing I haven't done yet is to
copy the boot sector from sda, and then write it to the sdb drive. 
However, that being said, that "shouldn't" be necessary.  I've read
numerous reviews that praise the virtues of Linux software raid, but
so far I'm not convinced.  Someone help me from embracing the "Dark
Side of the Force"!

TIA

Russ