Boot new machine with CENTOS LiveCD.
Creating swap, boot and root partition
fdisk /dev/sda # create swap n p 1 enter +16G # create boot n p 2 enter +512M # create root partition n p 3 enter +225G # change partition to raid t 1 fd t 2 fd t 3 fd # activate boot on 2nd partition a 2 w fdisk /dev/sdb #repeat above steps.
Verify partitions
fdisk -l /dev/sda Disk /dev/sda: 2000.4 GB, 2000398934016 bytes 255 heads, 63 sectors/track, 243201 cylinders, total 3907029168 sectors Units = sectors of 1 * 512 = 512 bytes Sector size (logical/physical): 512 bytes / 512 bytes I/O size (minimum/optimal): 512 bytes / 512 bytes Disk identifier: 0x0000566e Device Boot Start End Blocks Id System /dev/sda1 2048 33556479 16777216 fd Linux raid autodetect /dev/sda2 * 33556480 34605055 524288 fd Linux raid autodetect /dev/sda3 34605056 506464255 235929600 fd Linux raid autodetect fdisk -l /dev/sdb Disk /dev/sdb: 2000.4 GB, 2000398934016 bytes 255 heads, 63 sectors/track, 243201 cylinders, total 3907029168 sectors Units = sectors of 1 * 512 = 512 bytes Sector size (logical/physical): 512 bytes / 512 bytes I/O size (minimum/optimal): 512 bytes / 512 bytes Disk identifier: 0x000567b2 Device Boot Start End Blocks Id System /dev/sdb1 2048 33556479 16777216 fd Linux raid autodetect /dev/sdb2 * 33556480 34605055 524288 fd Linux raid autodetect /dev/sdb3 34605056 506464255 235929600 fd Linux raid autodetect
Create RAID partitions
mdadm -C /dev/md0 --metadata=1.1 --level=1 --raid-devices=2 --name=ramdisk /dev/sda1 /dev/sdb1 mdadm -C /dev/md1 --metadata=1.0 --level=1 --raid-devices=2 --name=bootdisk /dev/sda2 /dev/sdb2 mdadm -C /dev/md2 --metadata=1.1 --level=1 --raid-devices=2 --name=root /dev/sda3 /dev/sdb3
Format RAID partitions
mkfs.ext3 /dev/md0 && mkfs.ext3 /dev/md1 && mkfs.ext4 /dev/md2 # format swap partition mkswap /dev/md0
Mount partitions
mkdir /mnt/s mount /dev/md2 /mnt/s mkdir /mnt/s/boot mount /dev/md1 /mnt/s/boot
Copy TAR backup from backup server to local disk
rsync --progress -av yourBackupServer:/yourBackupFile.tgz /mnt/s/
Extract TAR backup local disk
cd /mnt/s && tar -zxvf de6.tgz
Mount system partitions
mkdir /mnt/s/dev mkdir /mnt/s/proc mkdir /mnt/s/sys mount --bind /dev /mnt/s/dev/ mount --bind /proc /mnt/s/proc/ mount --bind /sys /mnt/s/sys/
Chroot
chroot /mnt/s /bin/bash
Update mdraid configuration
mdadm --examine --scan >> /etc/mdadm.conf
Verify mdraid configuration
cat /etc/mdadm.conf # mdadm.conf written out by anaconda MAILADDR root AUTO +imsm +1.x -all ARRAY /dev/md/ramdisk metadata=1.1 UUID=0711c371:dbb17d31:94eb870d:bda39400 name=rescue:ramdisk ARRAY /dev/md/bootdisk metadata=1.0 UUID=0d7bbde6:9b8e6e58:061ba120:58999b0d name=rescue:bootdisk ARRAY /dev/md/root metadata=1.1 UUID=2df86329:6cdd1e92:e42cc596:1290dea5 name=rescue:root
Update fstab with UUIDS of the newly created RAID partitions
ls /dev/disk/by-uuid/ -lha total 0 drwxr-xr-x 2 root root 120 Sep 16 19:32 . drwxr-xr-x 5 root root 100 Sep 16 19:29 .. lrwxrwxrwx 1 root root 9 Sep 16 19:32 2838827a-499f-477d-8329-a6c42c780156 -> ../../md0 lrwxrwxrwx 1 root root 11 Sep 16 19:29 40c4ea95-0ecc-4c51-9f3e-e49d8f62f160 -> ../../loop0 lrwxrwxrwx 1 root root 9 Sep 16 19:32 5c94dc94-823b-4cc0-a848-827816eb56a3 -> ../../md1 lrwxrwxrwx 1 root root 9 Sep 16 19:32 f1d027bf-d2fc-499b-9db0-19f9b0780e28 -> ../../md2 vi /etc/fstab UUID=2838827a-499f-477d-8329-a6c42c780156 none swap sw 0 0 UUID=5c94dc94-823b-4cc0-a848-827816eb56a3 /boot ext3 defaults 0 0 UUID=f1d027bf-d2fc-499b-9db0-19f9b0780e28 / ext4 defaults 0 0 <strong>Verify configuration</strong> cat /etc/fstab proc /proc proc defaults 0 0 none /dev/pts devpts gid=5,mode=620 0 0 UUID=2838827a-499f-477d-8329-a6c42c780156 none swap sw 0 0 UUID=5c94dc94-823b-4cc0-a848-827816eb56a3 /boot ext3 defaults 0 0 UUID=f1d027bf-d2fc-499b-9db0-19f9b0780e28 / ext4 defaults 0 0
Fix Grub on MBR record of both RAID1 disks
grub root (hd0,1) setup (hd0) root (hd1,1) setup (hd1) quit vi /boot/grub/grub.conf #remove possibly logical volumes: rd_LVM_LV=vg_livecd/lv_swap rd_LVM_LV=vg_livecd/lv_root # add root partitions UUID root=UUID=f1d027bf-d2fc-499b-9db0-19f9b0780e28 # add us keyboard KEYBOARDTYPE=pc KEYTABLE=us LANG=en_US.UTF-8 SYSFONT=latarcyrheb-sun16 # add mdraid root partition + swap UUID: rd_MD_UUID=2df86329:6cdd1e92:e42cc596:1290dea5 rd_MD_UUID=0711c371:dbb17d31:94eb870d:bda39400 Verify configuration cat /boot/grub/grub.conf timeout 5 default 0 title CentOS (2.6.32-279.19.1.el6.x86_64) root (hd0,1) kernel /boot/vmlinuz-2.6.32-279.19.1.el6.x86_64 ro root=UUID=f1d027bf-d2fc-499b-9db0-19f9b0780e28 rd_MD_UUID=2df86329:6cdd1e92:e42cc596:1290dea5 rd_MD_UUID=0711c371:dbb17d31:94eb870d:bda39400 KEYBOARDTYPE=pc KEYTABLE=us LANG=en_US.UTF-8 SYSFONT=latarcyrheb-sun16 rd_NO_LUKS rd_NO_DM nomodeset initrd /boot/initramfs-2.6.32-279.19.1.el6.x86_64.img mv /boot/initramfs-2.6.32-279.19.1.el6.x86_64.img /boot/initramfs-2.6.32-279.19.1.el6.x86_64.imgbackup mkinitrd -f -v /boot/initramfs-2.6.32-279.19.1.el6.x86_64.img 2.6.32-279.19.1.el6.x86_64
Below is optional, but for my work mandatory
Fix network
vi /etc/hosts yourIpAddress myserver.domain.com
vi /etc/sysconfig/network
HOSTNAME=your_custom_host.com
vi /etc/resolv.conf
nameserver IpOfYourNameServer
nameserver IpOfYourNameServer2
vi /etc/sysconfig/network-scripts/route-eth0
GATEWAY0=IpOfYourDefaultGateWay
vi /etc/sysconfig/network-scripts/ifcfg-eth0
#remove old hw address: HWADDR=XX:XX:XX:XX
IPADDR=YourIpAddress
NETMASK=YourSubnetMask
#remove entry in udev if your backup is restored to different machine
vi /etc/udev/rules.d/70-persistent-net.rules
#SUBSYSTEM=="net", ACTION=="add", DRIVERS=="?*", ATTR{address}=="00:0c:xx:xx:xx: af", ATTR{type}=="1", KERNEL=="eth*", NAME="eth0"Restore to different hardware
If you are restoring the backup from a machine that used different hardware than the target server has, you have to recompile the kernel. If you have another machine that uses the same hardware of the target machine you could copy the kernel from that machine the following way:
<span style="font-family: Consolas, Monaco, monospace; font-size: 12px; line-height: 18px;">rsync -avz differentmachine:/lib/modules/2.6.32-358.14.1.el6.x86_64 /lib/modules/ </span>rsync -avz differentmachine:/boot/vmlinuz-2.6.32-358.14.1.el6.x86_64 /boot/ mkinitrd -f -v /boot/initramfs-2.6.32-358.14.1.el6.x86_64.img 2.6.32-358.14.1.el6.x86_64
If you still get errors when booting then compare the modprobe.d folder. Sometimes you have to blacklist specific modules to bypass bugs.
Troubleshooting
If rebooting does not work at all, just boot again with LiveCD. CENTOS LiveCD resets the MD numbering in reversed order and starting at md127. So md0 is md127, md1 md126 and md2 is md125. Mount your OS quickly this way:
mkdir /mnt/s mount /dev/md125 /mnt/s mkdir /mnt/s/boot mount /dev/md126 /mnt/s/boot mkdir /mnt/s/dev mkdir /mnt/s/proc mkdir /mnt/s/sys mount --bind /dev /mnt/s/dev/ mount --bind /proc /mnt/s/proc/ mount --bind /sys /mnt/s/sys/ chroot /mnt/s /bin/bash