gmirror Issues

[Joe Kelsey]

I am having a real hard time with gmirror.  I recently bought two new 
400G SATA disks and I want to mirror them.  I think I am following the 
directions, but I am not sure.

I generally do the following steps:

edit /boot/loader.conf to add geom_mirror_load.
reboot into single-user
gmirror label -v -b round-robin gm0 ad4s1 ad6s1
bsdlabel -w mirror/gm0
bsdlabel -e mirror/gm0
newfs mirror/gm0a

When I attempt to perform the newfs, it generally goes through all of 
the backup super blocks and hangs the system at the end of the newfs.  
At that point, my only recourse is pushing the reset button.  When the 
system comes up, GEOM_MIRROR tries to rebuild one of the providers 
(usually ad4s1), but never seems to succeed.

Anyway, the first problem I had was not having geom_mirror loaded.  The 
only solution seems to be adding the load to /boot/loader.conf.  None of 
the manual pages or handbook pages says anything about this except when 
discusssing making your system disk mirrored.  I am not doing that.

So, after loading the mirror stuff, I regularly lock up the system by 
trying to perform simple activities on the mirror.  What do I need to do 
differently?

Here are the relevant dmesg lines:
atapci0: <SiI 3512 SATA150 controller> port 
0xa000-0xa007,0x9800-0x9803,0x9400-0x9407,0x9000-0x9003,0x8800-0x880f 
mem 0xfba00000-0xfba001ff irq 18 at device 13.0 on pci0
ata2: <ATA channel 0> on atapci0
ata3: <ATA channel 1> on atapci0
ad4: 381554MB <Seagate ST3400620AS 3.AAC> at ata2-master SATA150
ad6: 381554MB <Seagate ST3400620AS 3.AAC> at ata3-master SATA150

FreeBSD zircon.zircon.seattle.wa.us 6.2-STABLE FreeBSD 6.2-STABLE #0: 
Sat Mar 24 16:32:06 PDT 2007     
root at zircon.zircon.seattle.wa.us:/usr/obj/usr/src/sys/ZIRCON amd64 amd64 
amd64 FreeBSD

/Joe