[mythtv-users] Kernel Panic - SCSI & IDE

Sat Jul 8 20:34:15 UTC 2006

Bruce,

This may be a little too much hand holding for you, but others who  
search the archives might find it helpful.

The commands below work on my Fedora Core 3 machine, it is a Dell  
PowerEdge 1650 with dual 1266MHz PIIIs, 1GB RAM, two SCSI 36GB drives  
using the on-board RAID, appearing as /dev/sda to Linux, and  
partitioned as /dev/sda1 /boot, /dev/sda2 /, /dev/sda3 swap, /dev/ 
sda6 /home. I also have four 160GB USB2.0 drives connected to a  
USB2.0 card I added in the 64 bit slot. The drives are set up as a  
640GB Logical Volume striped across the drives. There is a PVR-250 in  
the computer's 32 bit slot.

If I were you I would:

Remove the IDE drive for the moment.

Install an O/S and get everything working.
As root, run these commands:
mkdir -m 600 -p /var/spool/check_points
touch /var/spool/check_points/after_os_install

You should have room to do a quick backup of everything.
Make a place for the backups, unmount the boot partition, and dump a  
compressed image of it to a backup file.

mkdir -p /var/backups
umount /boot
dd if=/dev/sda1 | gzip -c >/var/backups/boot.image.gz

Backup the root partition.
tar cvjf /var/backups/root_after_os_install.tar.gz --exclude '/var/ 
backups/*' /

Install KnoppMyth (or something else) and let the setup do it's  
thing. You can use set it up to use /video and /music for storage.  
Just make them folders off the root for the time being.
When everything is playing nicely together, shutdown the machine  
completely, and power off (that's important).
Boot it up again.
Make sure everything still works as it should. Try recording a show,  
watching TV, etc.
Shut the machine down completely, and turn it off (again).
Boot it up.
Everything still working?
As root, run this command:
touch /var/spool/check_points/after_myth_install

Now, back up just the changes since our last backup:
find . -newer /var/spool/check_points/after_os_install \
	-a ! -type d | tar cvjf backups/after_myth_install.tar.bz2 \
	-T - --exclude 'backups/*'

Shut it down and connect the IDE drive.
Boot it up.
Everything still working?

Now, you can begin creating your LVM set on the IDE drive.

# warning, the following commands will destroy whatever is on the  
drive hda.
pvcreate /dev/hda
vgcreate myth_group /dev/hda
lvcreate -L 18000M myth_group
lvcreate -L 18000M myth_group
mkfs.xfs /dev/myth_group/lvol0
mkfs.xfs /dev/myth_group/lvol1

Be sure the backend is shut down:
/etc/init.d/mythbackend stop

Mount the partitions and copy files over.
mkdir /mnt/lvol0
mkdir /mnt/lvol1
mount /dev/myth_group/lvol0 /mnt/lvol0
mount /dev/myth_group/lvol1 /mnt/lvol1
cp -a /video/* /mnt/lvol0
cp -a /music/* /mnt/lvol1

Unmount the partitions.
umount /mnt/lvol0
umount /mnt/lvol1

Add lines to your fstab so they will be mounted automatically when  
you boot.
/dev/myth_group/lvol0      /video                  xfs      
defaults,suid   0 0
/dev/myth_group/lvol1      /music                  xfs      
defaults,suid   0 0

Try to mount them:
mount /video
mount /music

Change the owner and group so Myth can use them:
chown mythtv:mythtv /video /music
chmod u=rwx,g=rwx /video /music

And see how much space is available:
df -h /video /music

If you see them listed, you're in business. Start the backend and see  
how it likes them:
/etc/init.d/mythbackend start
tail -f /var/log/mythtv/mythbackend.log

You should see normal messages about the backend starting, scheduling  
shows, etc.

Now see if things in the frontend work, recording programs, watching  
live TV, etc.

Once again, mark your place:
touch /var/spool/check_points/after_lvm_setup

And, another backup:
find . -newer /var/spool/check_points/after_myth_install \
	-a ! -type d | tar cvjf backups/after_lvm_setup.tar.bz2 \
	-T - --exclude 'backups/*'

Now you can shutdown all the way to power off again, boot the  
machine, and see if everything works, the LVM partitions are mounted,  
etc.

All the turning off is to be sure the hardware (like the tuner card)  
are truly reset before the system comes up. That way, you will know  
that if the power goes off, and back on, the system will come back up  
and work correctly. The shutdowns are also so that UDEV will process  
it's rules, permissions, and configuration (all in /etc/udev) and set  
the hardware up correctly. I've had several problems with UDEV  
wanting the /dev/video* to be owned by root with 660 permissions,  
meaning Myth couldn't access them. I've also had problems with the  
USB drives changing devices at random (i.e. /dev/sdb becomes /dev/ 
sdd, etc.) but that's another protracted email :-).

Regards,
   JJ

---
"America goes not abroad in search of monsters to destroy." -- John  
Quincy Adams

On 08-Jul-2006, at 13:09, Bruce Nordstrand wrote:

> Hi all
>
> before I retry an install on my machine I have to ask if this will  
> work.
> I have spent the last 2 days trying various flavors of Myth on my
> proof-of-concept box, all failing in various ways. I have a sneaking
> suspicion I cannot do want I want to do, so I have finally given in  
> and
> have to ask you guys.
>
> My machine is an IBM eSeries x200 server that has a 29160LP Adaptec  
> SCSI
> card with an IBM ST31840LW 18GB 160Mbs 10,000 RPM SCSI drive in it
> (sda). The machine is a PIII 933Mhz with 384Mb ram (to be upgraded to
> more later on....maybe). I added a 40GB 7200rpm Segate Barracuda drive
> (hda) along with a DVD burner (hdb).
>
> So far I have been unsuccessful at installing KnoppMyth which just
> didn't want to work with this configuration at all. I have just  
> finished
> installing a Fedora Core 4 version and while it boots from the SCSI
> drive, it fails with a kernel panic complaining about the LVM I  
> created.
>
> During setup I created sda1 as /boot (1GB - ext3), sda2 as swap (1GB),
> sda3 as / (16GB - ext3). The entire IDE drive was allocated to an LVM
> group and then 2 virtual partitions were created within that group for
> /video (18GB) and /music (19GB). I set the install to write the MBR to
> sda after changing the order of sda and hda to make sure sda was the
> "first" drive.
>
> I did it this way so I can add bigger IDE drives later on (can't  
> afford
> any more SCSI drives!).
>
> The FC4 install went fine and rebooted. That's when things went pear
> shaped. After starting Linux it dies with a kernel panic. The message
> is: not synching VFS: Unable to mount root fs on unknown-block(3,1).
>
> Does anyone know what this means and , better still, know if I can fix
> it? Actually anything at all would help!
>
> Ever hopeful I can get this machine to work as is...
>
> Cheers
> Bruce
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