Migrate CentOS 5.4 to Ovirt - Revision history

Michael.mast: /* Purpose */

2018-06-16T23:34:52Z

Purpose

Michael.mast: /* Install Grub */

2018-06-16T23:32:41Z

Install Grub

Michael.mast: /* Fixing Grub */

2018-06-16T23:31:47Z

Fixing Grub

Michael.mast: /* Fixing Grub */

2018-06-16T23:26:39Z

Fixing Grub

Michael.mast: /* Install Grub */

2018-06-16T23:22:57Z

Install Grub

Michael.mast: /* Installing and fixing grub */

2018-06-16T23:08:23Z

Installing and fixing grub

Michael.mast: /* Steps */

2018-06-16T23:00:26Z

Steps

Michael.mast: /* Rsync */

2018-06-16T22:48:57Z

Rsync

Michael.mast: /* rsync root partition */

2018-06-16T22:42:19Z

rsync root partition

Michael.mast: Created page with "==Purpose== A very old install of CentOS 5.4 needed to be migrated to an Ovirt Hypervisor. This was a special install of Hylafax, a productions server that could not be taken..."

2018-06-16T22:40:59Z

Created page with "==Purpose== A very old install of CentOS 5.4 needed to be migrated to an Ovirt Hypervisor. This was a special install of Hylafax, a productions server that could not be taken..."

New page

==Purpose==
A very old install of CentOS 5.4 needed to be migrated to an Ovirt Hypervisor. This was a special install of Hylafax, a productions server that could not be taken offline, and was critical to business operations.
<br>
<br>
Several attempts were made to replicate the server and it's 500GB of data. Including running a disk dump over ssh to the destination VM and another physical server.
==Steps==
My final idea was to rsync the system to the new VM disk, install grub, then go from there.
===Rsync===
First I created a VM in Ovirt with a disk large enough to hold the data, plus extra as the existing server was running out of space.
<br>
After that was completed I
*booted off a live fedora ISO
*ran fdisk
**created first partition with enough space for the boot partition.
**created second partition with rest of space.
*started sshd
*created a password for liveuser
*On the old server, ran ssh-copy-id liveuser@newvm to ensure key based ssh was setup.
====rsync boot partition====
While still in the live fedora shell
*mounted /dev/sda1 on /mnt
*chown liveuser /mnt
Then on the old server ran the following dry run to check for errors.
<pre>
rsync -avn /boot/* liveuser@newvm:/mnt/ &> rsync.log
</pre>
Then the live transfer
<pre>
rsync -avz /boot/* liveuser@newvm:/mnt/ &> rsync.log
</pre>
====rsync root partition====
Back in the line fedora shell
*umount

@@ Line 66: / Line 66: @@
 grub-install /dev/sda
 </pre>
 SUCCESS! We were able to boot grub, but then kernel panics as it was unable to find the root partition.
 ====Fixing Grub====
 The first thing I did was to rebuild initrd with virtio modules. Thankfully the old server already had virtio modules available.<ref>https://wiki.centos.org/TipsAndTricks/CreateNewInitrd</ref>

@@ Line 92: / Line 92: @@
 <br>
 Back in the CentOS 7 rescue shell, and chroot back into the CentOS 5.4
 uuid=$(ls -l /dev/disk/by-uuid | grep sda2 | awk '{print $9}')
-sed
+sed -i "s|/dev/sda2|UUID=$uuid|" /boot/grub/grub.conf
 <br>
 <br>

← Older revision		Revision as of 23:26, 16 June 2018
Line 89:		Line 89:
	</pre>		</pre>
	At this point I was still getting a kernel panic with root mount errors, though I did see the virtio modules being loaded. Everything I had read online said to NOT use UUIDs in grub, but since I was out of ideas it was the next thing to try.		At this point I was still getting a kernel panic with root mount errors, though I did see the virtio modules being loaded. Everything I had read online said to NOT use UUIDs in grub, but since I was out of ideas it was the next thing to try.
		+	<br>
		+	<br>
		+	Back in the CentOS 7 rescue shell, and chroot back into the CentOS 5.4
		+	uuid=$(ls -l /dev/disk/by-uuid \| grep sda2 \| awk '{print $9}')
		+	sed
		+	<br>
		+	<br>

@@ Line 61: / Line 61: @@
 **mount /dev/sda1 /mnt/sysimage/boot
 *Copied /mnt/sysimage/usr/share/grub/x86_64-redhat to /usr/share/grub/x86_64-redhat because the rescue environment did not have this.
-*Installed grub onto the new disk
+*Updated grub.conf with the new drive information (switching from c0d0 to sda)
 <pre>
 grub-install /dev/sda
 </pre>

@@ Line 52: / Line 52: @@
 *Jumped to the rescue shell. At this point it did not find any linux volumes, which was something I had seen after performing the disk dump.
 *Ran fdsik to verify the partitions, unlike the disk dump I was able to see the two volumes I had created previously. PROGRESS!
 *mounted both partitions as follows
 **mount /dev/sda2 /mnt/sysimage
 **mount /dev/sda1 /mnt/sysimage/boot
-*chroot /mnt/sysimage
+*Copied /mnt/sysimage/usr/share/grub/x86_64-redhat to /usr/share/grub/x86_64-redhat because the rescue environment did not have this.

@@ Line 1: / Line 1: @@
 ==Purpose==
-A very old install of CentOS 5.4 needed to be migrated to an Ovirt Hypervisor. This was a special install of Hylafax, a productions server that could not be taken offline, and was critical to business operations.
+A very old install of CentOS 5.4 needed to be migrated to an Ovirt Hypervisor. This was a special install of Hylafax, a production server that could not be taken offline, and was critical to business operations.
 <br>
 <br>
 Several attempts were made to replicate the server and it's 500GB of data. Including running a disk dump over ssh to the destination VM and another physical server.
 ==Steps==
 My final idea was to rsync the system to the new VM disk, install grub, then go from there.

@@ Line 14: / Line 14: @@
 **created first partition with enough space for the boot partition.
 **created second partition with rest of space.
 *started sshd
 *created a password for liveuser
@@ Line 46: / Line 47: @@
 </pre>
 *After a day or so this finished without any strange errors, beyond the expected "files disappeared" that you would get from replicating a live system.

@@ Line 19: / Line 19: @@
 ====rsync boot partition====
 While still in the live fedora shell
-*mounted /dev/sda1 on /mnt
+*mount /dev/sda1 on /mnt
 *chown liveuser /mnt
 Then on the old server ran the following dry run to check for errors.
@@ Line 33: / Line 33: @@
 *umount the last partition used for the boot partition on /mnt
 *mount the other partition created (mount /dev/sda2 /mnt)
+*chown liveuser /mnt (shouldn't be needed, just in case).

@@ Line 31: / Line 31: @@
 ====rsync root partition====
 Back in the line fedora shell
-*umount
+*umount the last partition used for the boot partition on /mnt