Converting from ata-raid to gmirror

[Toomas Aas]

Hello!

I'm currently running FreeBSD 6.2-RELEASE (amd64) on a system based on 
Intel SE7230NH1-E motherboard, which has Intel ICH7R integrated 
softraid. The machine has two 500 GB drives which are configured as 
RAID1 in BIOS. Unfortunately, this setup seems to have some stability 
issues which I can't figure out how to solve. Specifically, when the 
storage subsystem is put under heavy load (such as doing nightly 
backups) the kernel starts spitting out horrible error messages such as:

FAILURE - out of memory in ata_raid_init_request
g_vfs_done():ar0s1f[WRITE(offset=8091172864, length=16384)]error = 5
FAIg_vfs_done():ar0LURE - out of memsory in ata_raid_1init_reqfu[eWsRItTE(o
ffset=8091F1A8I9LU2R4E8 ,-  oleuntg tohf= 16m3e8m4o)ry]e rirno ra t=a 5
_raid_init_requestg
  vfs_done():ar0s1f[WRITE(offsFAeItL=UR8E0 9-1 2o05u6t3 2o,f 
lmeengmtoh=ry1 6i3n8 4a)t]ae_rrraoird _=in i5t

If it looks like garbage, then yes, this is how it appears in 
/var/log/messages. I'm seriously afraid that similar corruption is 
sneaking into important user files.

Only thing I can think of is converting this setup from BIOS-based RAID 
to gmirror. This would involve, I think, modifying /etc/fstab so that it 
references ad4 instead of ar0, then permanently breaking the mirror in 
BIOS, booting up the system with single disk and then basically 
following the gmirror chapter in the handbook. Correct?

I'm also a little uncertain about "permanently breaking the mirror" 
part. I've read all the motherboard and LSI docs I can find and this 
topic isn't covered anywhere. Some googling seems to hint that it can be 
done, but nothing too definitive. If anyone happens to have the exact 
configuration menu map for Intel Matrix RAID (LSI Megaraid V3) as it 
appears on SE7230NH1-E motherboard, it would be appreciated. Or if 
anyone can suggest what to do to fix the system without converting to 
gmirror, then that, of course, would also be appreciated.

--
Toomas