Installing Debian Wheezy (testing) With debootstrap From A Grml Live Linux
Version 1.0
Author: Falko Timme
This tutorial explains how to install Debian Wheezy (testing) with the help of debootstrap from a Grml Live Linux system (like it is used as a rescue system at Webtropia). This should work - with minor changes - for other Debian and Ubuntu versions as well. By following this guide, it is possible to configure the system to your needs (OS version, partitioning, RAID, LVM, etc.) instead of depending on the few pre-configured images that your server provider offers.
I do not issue any guarantee that this will work for you!
1 Preliminary Note
The server I'm using in this tutorial has two hard drives. I want to use software RAID1 and LVM for this server.
Before you boot the system into rescue mode, you should take note of its network settings so that you can use the same network settings for the new system. For example, if you use Debian or Ubuntu on the system, take a look at /etc/network/interfaces:
cat /etc/network/interfaces
It could look as follows:
auto lo
iface lo inet loopback
auto eth0
iface eth0 inet static
address <ip_address>
netmask <netmask>
broadcast <broadcast>
gateway <gateway>
iface eth0 inet6 static
address <ipv6_address>
netmask 64
up ip -6 route add <ipv6_gateway> dev eth0
down ip -6 route del <ipv6_gateway> dev eth0
up ip -6 route add default via <ipv6_gateway> dev eth0
down ip -6 route del default via <ipv6_gateway> dev eth0 |
2 Partitioning
Now boot into the Grml rescue system.
In the rescue system, let's check of software RAID and LVM are in use for the hard drives (if so, we need to remove them before we partition the hard drives):
The commands
lvdisplay
vgdisplay
pvdisplay
tell you if there are logical volumes, volume groups, and block devices being used for LVM. If so, you can remove them as follows (make sure you use the correct data, as displayed by the three above commands):
lvremove /dev/vg0/root
vgremove vg0
pvremove /dev/md1
Let's check if software RAID is in use:
cat /proc/mdstat
If the output is as below, you have to RAID devices, /dev/md0 and /dev/md1 which have to be removed:
root@grml ~ # cat /proc/mdstat
Personalities : [linear] [raid0] [raid1] [raid10] [multipath]
md0 : active raid1 sda1[0] sdb1[1]
530048 blocks [2/2] [UU]
md1 : active raid1 sda2[0] sdb2[1]
104856192 blocks [2/2] [UU]
unused devices: <none>
root@grml ~ #
Remove them as follows:
mdadm --stop /dev/md0
mdadm --stop /dev/md1
Double-check that no RAID devices are left:
cat /proc/mdstat
root@grml ~ # cat /proc/mdstat
Personalities : [linear] [raid0] [raid1] [raid10] [multipath]
unused devices: <none>
root@grml ~ #
Let's take a look at the current partitioning:
fdisk -l
root@grml ~ # fdisk -l
Disk /dev/sdb: 2000.4 GB, 2000398934016 bytes
255 heads, 63 sectors/track, 243201 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Sector size (logical/physical): 512 bytes / 4096 bytes
I/O size (minimum/optimal): 4096 bytes / 4096 bytes
Disk identifier: 0x957081d4
Device Boot Start End Blocks Id System
/dev/sdb1 1 66 530112+ fd Linux raid autodetect
Partition 1 does not end on cylinder boundary.
Partition 1 does not start on physical sector boundary.
/dev/sdb2 66 13120 104856256 fd Linux raid autodetect
Disk /dev/sda: 2000.4 GB, 2000398934016 bytes
255 heads, 63 sectors/track, 243201 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Sector size (logical/physical): 512 bytes / 4096 bytes
I/O size (minimum/optimal): 4096 bytes / 4096 bytes
Disk identifier: 0x000cdcbd
Device Boot Start End Blocks Id System
/dev/sda1 1 66 530112+ fd Linux raid autodetect
Partition 1 does not end on cylinder boundary.
Partition 1 does not start on physical sector boundary.
/dev/sda2 66 13120 104856256 fd Linux raid autodetect
root@grml ~ #
Because I have two identical hard drives, I want to use software RAID1 plus LVM (because of its felxibility). Because LVM cannot be used on the boot partition, I have to create a separate /boot partition where I use RAID1 without LVM.
To do this, I delete the existing partitions from /dev/sda, create two new ones (a small one of about 512MB for /boot and a large one; you could of course use all remaining space for the large partition, but I tend to leave some space unused because bad sectors tend to appear in the outer areas of a spinning disk - if you use an SSD, it's ok to use the whole disk) with Linux raid autodetect as the partition type:
root@grml ~ # fdisk /dev/sda
The device presents a logical sector size that is smaller than
the physical sector size. Aligning to a physical sector (or optimal
I/O) size boundary is recommended, or performance may be impacted.
WARNING: DOS-compatible mode is deprecated. It's strongly recommended to
switch off the mode (command 'c') and change display units to
sectors (command 'u').
Command (m for help): <-- d
Partition number (1-4): <-- 1
Command (m for help): <-- d
Selected partition 2
Command (m for help): <-- n
Command action
e extended
p primary partition (1-4)
<-- p
Partition number (1-4): <-- 1
First cylinder (1-243201, default 1): <-- ENTER
Using default value 1
Last cylinder, +cylinders or +size{K,M,G} (1-243201, default 243201): <-- +512M
Command (m for help): <-- t
Selected partition 1
Hex code (type L to list codes): <-- fd
Changed system type of partition 1 to fd (Linux raid autodetect)
Command (m for help): <-- n
Command action
e extended
p primary partition (1-4)
<-- p
Partition number (1-4): <-- 2
First cylinder (66-243201, default 66): <-- ENTER
Using default value 66
Last cylinder, +cylinders or +size{K,M,G} (66-243201, default 243201): <-- 240000 (I tend to leave some space unused here)
Command (m for help): <-- t
Partition number (1-4): <-- 2
Hex code (type L to list codes): <-- fd
Changed system type of partition 2 to fd (Linux raid autodetect)
Command (m for help): <-- w
The partition table has been altered!
Calling ioctl() to re-read partition table.
WARNING: If you have created or modified any DOS 6.x
partitions, please see the fdisk manual page for additional
information.
Syncing disks.
root@grml ~ #
Next I run...
sfdisk -d /dev/sda | sfdisk --force /dev/sdb
... to copy the partitioning scheme from /dev/sda to /dev/sdb so that they are identical on both disks.
Run...
mdadm --zero-superblock /dev/sda1
mdadm --zero-superblock /dev/sda2
mdadm --zero-superblock /dev/sdb1
mdadm --zero-superblock /dev/sdb2
... to remove any remainders from previous RAID arrays from the partitions.
Now we create the RAID array /dev/md0 from /dev/sda1 and /dev/sdb1...
mdadm --create /dev/md0 --level=1 --raid-disks=2 /dev/sda1 /dev/sdb1
... and /dev/md1 from /dev/sda2 and /dev/sdb2:
mdadm --create /dev/md1 --level=1 --raid-disks=2 /dev/sda2 /dev/sdb2
Let's check with:
cat /proc/mdstat
As you see, we have two new RAID1 arrays:
root@grml ~ # cat /proc/mdstat
Personalities : [linear] [raid0] [raid1] [raid10] [multipath]
md1 : active raid1 sdb2[1] sda2[0]
1927269760 blocks [2/2] [UU]
[>....................] resync = 0.0% (347136/1927269760) finish=185.0min speed=173568K/sec
md0 : active raid1 sdb1[1] sda1[0]
530048 blocks [2/2] [UU]
unused devices: <none>
root@grml ~ #
Let's put an ext4 filesystem on /dev/md0:
mkfs.ext4 /dev/md0
Prepare /dev/md1 for LVM:
pvcreate /dev/md1
Create the volume group vg0:
vgcreate vg0 /dev/md1
Create a logical volume for / with a size of 100GB:
lvcreate -n root -L 100G vg0
Create a logical volume for swap with a size of 10GB:
lvcreate -n swap -L 10G vg0
Run:
lvscan
If all logical volumes are shown as ACTIVE, everything is fine:
root@grml ~ # lvscan
ACTIVE '/dev/vg0/root' [100,00 GiB] inherit
ACTIVE '/dev/vg0/swap' [10,00 GiB] inherit
root@grml ~ #
If not, run...
vgchange -ay
... and check with lvscan again.
Next create filesystems on /dev/vg0/root and /dev/vg0/swap:
mkfs.ext4 /dev/vg0/root
mkswap /dev/vg0/swap
Mount the root volume to /mnt, create a few diretories and mount /dev/md0 to /mnt/boot:
mount /dev/vg0/root /mnt
cd /mnt
mkdir boot
mkdir proc
mkdir dev
mkdir sys
mkdir home
mount /dev/md0 boot/
Create an fstab for the new system:
mkdir etc
cd etc
vi fstab
proc /proc proc defaults 0 0 /dev/md0 /boot ext4 defaults 0 2 /dev/vg0/root / ext4 defaults 0 1 /dev/vg0/swap none swap defaults,pri=1 0 0 |