Revisit of U320 and U160 SCSI bus problems with FC3t2.91
ngc4013 at cox.net
Mon Oct 11 00:59:42 UTC 2004
I have consistantly had problems with booting systems which have a JBOD
RAID box and FC2 or FC3t2.91. The problem remains the same and the work
around I figured out is only temporary.
The servers are Tyan dual Athlon 2200+ to 2800+ MP motherboards. A
couple of models have the U160 and a couple have the U320 SCSI bus on
board. In all cases the installation boots fine without the RAID
configured. I found that I could boot the boxes then configure RAID0 or
RAID5 and all would work very well until I perform a reboot. Upon
rebooting then the boot cycle drops out into single user mode with
errors relating to the RAID configuration in the /etc/raidtab file. Mind
you the configuration works just fine since I already had it running
when I first set it up.
So when I set out to install FC3t2.91 I figured maybe the same issues
would not be present since there is now mdadm to use instead of the old
raidtools. Again I installed the FC3t2.91 (BTW, in all cases the FC
installs are all full installs), then set out to set up the RAID. So
when I figured out what was needed to properly configure the
/etc/mdadm.conf file and set the RAID5 configuration up that I wished to
use, I started the RAID up and it ran fine as expected. The RAID was
accesible, writable, and I even did an NFS export which could be
accessed by other computers. Then I rebooted and the same type of
failure occured dropping me out into single user mode stating that there
was a problem with the /dev/md0 configuration.
My work around:
So what I discovered I could do was simple, but not really a fix for the
problem. I found that if I removed the mount point in the /etc/fstab file:
/dev/md0 /export/db-f8017_raid5 reiserfs defaults 0 0
and instead created a script file in /root which contained the following
mdadm -A /dev/md0
mdadm --details /dev/md0
mount -t reiserfs /dev/md0 /export/db-f8017_raid5
First line is close, but may be missing something since the files are on
my computers at work. Second line is just as a test reference point
showing that the RAID is active. Third line is my mount point while the
fourth shows the active mounts.
It accesses the same /etc/mdadm.conf file and the mount point is exactly
the way it originally was written in /etc/fstab. The system will boot
flawless and once logged in I can execute the script then the RAID comes
online and works perfectly.
So now I ask the questions... Why?? Any further info needed? Can someone
else setup a RAID box and recreate the problem to confirm that there are
issues in FC2 and FC3 with RAID durring the boot cycle? So far it
happens with a 144GB, 324GB, 657GB, and 2TB RAID boxes configured as
either RAID0 or RAID5, on internal U160 or U320 SCSI ports and an addon
U320 Adaptec card.
I think there is an issue with the events durring the boot cycle in that
it tries to mount the RAID before the RAID configuration sets the RAID up.
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