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Ubuntu bare metal restore steps
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Author
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Wybren Buijs
To do a bare metal restore, boot some sort of live environment that is able to
run burp.
Also before you try a bare-metal restore be sure the backups are backups of
the complete system and not just a part like /home.
In our case we use a 15.10 ubuntu live image booted from the network or a usb
drive.
On the backup server
You need to rename the keys because the live cd does not have these burp keys.
On the server go to /etc/burp/CA/ and rename the keys of the host you are
going to restore.
Get the password the client used from /etc/burp/clientconfdir/clientname
On the client.
Boot your live environment. If burp is not installed install it.
Edit /etc/burp/burp.conf
Change the following items in the config:
server = xx.xx.xx.xx (use the ip address to avoid resolving problems)
password = get it from the backup server
cname = get it from the backup server
If it is a new disk/system.
You first need to partition it in the right way.
But before doing that you need to know a few things.
What was the partition scheme?
Was it gpt or mbr
Was it a md raid system
Do I want the same scheme as before?
You could have a peek in /etc/fstab of your backup to find out if there was a
md raid installed.
You could use the size of your backup to determine the minimum partition space
needed for the restore.
You can set your swap with chroot.
But I think it might be of good practice if you want to be able to do smooth
bare-metal restores to make note how your systems should be partitioned.
So let's start creating a system with all disk space available - swap.
Start parted on the disk of choice and create 10GB primary partition and 2GB
swap.
Some parted info
http://www.thegeekstuff.com/2011/09/parted-command-examples/
For gpt
parted /dev/sda
mklabel gpt
mkpart boot 1049KB 10.5MB <- you need this for non uefi systems on uefi not
sure if you have to.
mkpart root 12MB 10GB
mkpart swap 10GB 12GB
set 1 bios_grub on
print
quit
For mbr
parted
mkpart primary 1049KB 10GB
mkpart extended 10GB 12GB
mkpart logical 10GB 12GB
set 1 boot on
set 2 lba off
print
quit
If your boot disk is a raid than you will need mdadm to create a new raid
system.
Mdadm is probably not installed so install it.
Start parted on sda
parted /dev/sda
mklabel gpt
mkpart boot 1049KB 2097KB
mkpart root 2098KB 12GB
mkpart swap 12GB 14GB
set 1 bios_grub on
set 2 raid on
set 3 raid on
Select sdb
select /dev/sdb
mklabel gpt
mkpart boot 1049KB 2097KB
mkpart root 2098KB 12GB
mkpart swap 12GB 14GB
set 1 bios_grub on
set 2 raid on
set 3 raid on
quit
Create your raids.
mdadm --create /dev/md0 --bitmap=internal --level=1 -n 2 /dev/sd[ab]2
mdadm --create /dev/md1 --bitmap=internal --level=1 -n 2 /dev/sd[ab]3
create partitions on your raids.
parted /dev/md0
mklabel loop
select /dev/md1
mklabel loop
quit
For all the following commands if you use a raid use md0 and md1 instead of
sda and sdb accept for installing grub.
Create an ext4 file system
mkfs.ext4 /dev/sda1
If you want you can already create your swap it can also be done when your
system is restored and running.
gpt-> mkswap /dev/sda3
mbr-> mkswap /dev/sda5
When done with the partitioning or your using a disk that was already
partitioned, mount the partition of the os.
In this case we mounted /dev/sda1 to /home/ubuntu/restore
mkdir /home/ubuntu/restore
sudo mount /dev/sda1 /home/ubuntu/restore
Start the restore procedure add -f if you need to overwrite files
sudo burp -a r -d /home/ubuntu/restore/
Once the restore is done you need to install grub to the boot drive to do this
we chroot into the restore directory.
If it is a new disk create the excluded proc dir.
mkdir restore/proc
Mount the critical virtual filesystems. Run the following as a single command:
for i in /dev /dev/pts /proc /sys /run; do sudo mount -B $i
/home/ubuntu/restore$i; done
If it complains about a missing folder in your restore folder like proc create
it.
Chroot into your restore system device:
sudo chroot /home/ubuntu/restore
If its a md raid first install mdadm
apt-get install mdadm
Install GRUB 2 (substitute the correct device with the device you used
before):
grub-install /dev/sda
If the system partitions are on a software RAID install GRUB 2 on all disks in
the RAID. Example (software RAID using /dev/sda and /dev/sdb):
grub-install /dev/sda
grub-install /dev/sdb
Recreate the GRUB 2 menu file (grub.cfg)
update-grub
Exit chroot: CTRL-D on keyboard
Reboot.
sudo reboot
If you did all of this on a new disk or system some things will be messed up.
Your fstab will have wrong uuid's in it. You should match them with your
current uuid's
You might need to create a swap space.
To check if you have a working swap
free
If all the numbers next to swap are 0 you have no swap
When it was a raid system check what the current name of your raid is it can
be quite different.
cat /proc/mdstat
Create and enable a swap
mkswap /dev/sda5
swapon /dev/sda5
Correct the uuids in your fstab.
Fist list your uuids.
ls -la /dev/disk/by-uuid
lrwxrwxrwx 1 root root 10 Apr 22 17:08 e4e0f3f6-f774-46a0-a476-ea56a00dd4cf -> ../../sda5
lrwxrwxrwx 1 root root 10 Apr 22 17:08 f757c477-2c7f-4073-a6ae-6d53625c3573 -> ../../sda1
If you do not have 2 uuid's you probably did not do the mkswap step.
Edit your fstab and change the uuid's for the correct ones
vi /etc/fstab
Info on installing grub
https://help.ubuntu.com/community/Grub2/Installing
Info on creating a swap.
https://www.centos.org/docs/rhel-sag-en-3/s1-swap-adding.html
Info on creating mdraid.
http://askubuntu.com/questions/505446/how-to-install-ubuntu-14-04-with-raid-1-using-desktop-installer
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