migrated my FC6 system to faster disk

When I was on Fedora Core 4, I had been using a fast, 250GB Western Digital SATA drive as my main root partition. Since I live in both XP and Fedora worlds, I divided up the drive into the following partitions:
/dev/sda1: XP boot (40GB)
/dev/sda2: Fedora Core 4 /boot (128MB)
/dev/sda3: Fedora Core 4 / (root) (120GB)
/dev/sda4: unused
/dev/sda5: swap (6GB)
/dev/sda6: FAT32 (to transfer files in between Linux and XP) (60GB)

This configuration allows me to dual boot XP and FC easily, as well as transfer files in between the two OSs. Speaking of NTFS-ext2/3 transfers, I'm slowing phasing out the FAT32 partition for transfers because I have had success using ntfs-3g (http://www.ntfs-3g.org) to write to and read from my NTFS partitions. NTFS-3g has been very solid for reading and writing from Linux to NTFS.

Earlier this year, I installed Fedora Core 6 as a development/test system on a separate 40GB drive. Doing the install this way instead of an upgrade of FC4 meant that I didn't have to cripple the FC4 system in case anything went wrong with FC6. As it happens, Cinelerra on FC6 happens to be the most stable Cinelerra I've used these past two years, apart from an audio sync issue on rendered videos. I correct the sync problem using the Nudge feature on each audio track, detailed here:
/2007/05/nudge-avidemux2-and-reminder-about.html

Lo these past six months, I have been editing on FC6, albeit on a slower IDE drive, a 7200RPM Barracuda. The 250GB SATA with 16MB memory cache is quite a bit faster. So the goal was to move the boot/root of the FC6 system to the boot/root of the faster SATA drive.

LVM versus ext3
The first issue I encountered was that the default installation of FC6 automatically creates a Volume Group and Logical Volumes instead of plain old ext2/ext3 filesystems. My FC4 system used ext3 for boot/root, so my original plan was to do a simple partimage backup of the two FC6 filesystems. That idea would not work, as FC6 was on LVM and partimage doesn't recognize LVM partitions.

As an experiment (and because I wanted to get up and running quickly), I simplified the plan to install the new drive in the machine, mount the FC4 filesystems on the fast drive, delete the content on them and replace the content with the FC6 system files. I'd have to then tweak fstab and grub.conf appropriately on the updated drive to make the whole thing work.

The Plan
1) install both drives in the same machine with FC6 as the primary system,
2) mount the FC4 partitions of the fast drive in FC6 (/mnt/fc4boot & /mnt/fc4root),
3) remove all the files off of the FC4 boot/root filesystems,
4) copy the files from the FC6 boot/root parts to the FC4 partitions,
5) carefully tweak grub.conf and fstab to reference the new partition scheme
6) hope for the best on reboot

Here is where we had "a few issues" as an old boss of mine would say.

Problems!
I guess it is my cursory knowledge of the boot process that got me into trouble. The first issue after performing these four steps was the following error:
mount: could not find filesystem '/dev/root'
setuproot: moving /dev failed: No such file or directory
setuproot: error mounting /proc: No such file or directory
setuproot: error mounting /sys: No such file or directory
switchroot: mount failed: No such file or directory
Kernel panic - not syncing: Attempted to kill init!

Ouch! That doesn't look good. Following the advice of this thread:
http://www.linuxquestions.org/questions/showthread.php?t=497332

First, using SysRescCD, I verified my partition labels on the fast drive using e2label:
e2label /dev/hdN
where N is the Fedora partition

I double-checked my grub.conf and fstab:

/boot/grub/grub.conf
Here's the old entry:
title Fedora Core (2.6.19-1.2911.fc6)
root (hd0,0)
kernel /vmlinuz-2.6.19-1.2911.fc6 ro root=/dev/VolGroup00/LogVol00
initrd /initrd-2.6.19-1.2911.fc6.img

Here's the new entry:
title Fedora Core (2.6.19-1.2911.fc6)
root (hd0,1)
kernel /vmlinuz-2.6.19-1.2911.fc6 ro root=LABEL=/
initrd /initrd-2.6.19-1.2911.fc6.img

Note the changes in bold that I needed to enter in order to move the root from the first partition on the older, slow drive to the second partition on the faster drive. Also, LVM goes away to be replaced by the simpler naming scheme of the ext3 formatted partition.

/etc/fstab
Secondly, the fstab changes as well, from:
/dev/VolGroup00/LogVol00 / ext3 defaults 1 1
/dev/VolGroup00/LogVol01 swap swap defaults 0 0

To:
LABEL=/ / ext3 defaults 1 1
/dev/sda5 swap swap defaults 0 0

The /boot entry stays the same:
LABEL=/boot /boot ext3 defaults 1 2

The output of e2label showed that my fast drive partition labels matched those in grub.conf and fstab. So no smoking gun there.

The next thing suggested in the thread was to create mkinitrd, the initial ram disk the Linux kernel uses for system files. Oh boy. I've forgotten about this one. I knew I had the correct partition labels, but I needed a little more background on mkinitrd and these articles helped:
http://www.faqs.org/docs/Linux-mini/Loopback-Root-FS.html
http://www.opennet.ru/docs/HOWTO/Kernel-HOWTO-11.html+creating+initrd
http://www.ibm.com/developerworks/linux/library/l-initrd.html

Redhat/Fedora has a nice utility called mkinitrd that simplifies many of the steps mentioned in the IBM and HOWTO articles above. I regenerated the initial ramdisk image on the new boot partition using the following command:
mkinitrd ./initrd-2.6.19-1.2911.fc6.img 2.6.19-1.2911.fc6

OK. There were no errors on creation and the file is there and has data:
-rw------- 1 root root 2398566 Sep 9 11:52 /boot/initrd-2.6.19-1.2911.fc6.img

Cool. Now for the moment of truth. The reboot! I powered down and waited for the system to come back up. Thankfully, the kernel got beyond the panic and booted properly! Hooray! However, I did see some errors still:
No volume groups found
Volume group "VolGroup00" not found
Unable to access resume device (/dev/VolGroup00/LogVol01)

But, the system loads fine and Cinelerra and all my apps seem to work. So I will have to research this error further.

Also, I saw when I started Evolution, I got the following error:
Error while storing folder 'Inbox'

Researching this, I saw that there were inconsistencies in the index files that Evolution creates. The workaround is simple: delete any mail folders in ~./evolution/mail/local with an extension of ev.~summary. These are indexing files only and you can safely remove them. Reference:
https://bugs.launchpad.net/ubuntu/+source/evolution/+bug/27014

For the past couple of days, I have been editing and Cinelerra is performing well. I'm glad I went through this exercise. Though, I really need to learn more about how to backup and restore LVM partitions. I might have saved myself some pain.

cheers!
The Mule