Installing Debian

(Updated: 2005-05-24)

Instructions for installing a very clean Debian GNU/Linux system that boots from RAID 1, and has RAID 1 or RAID 5 root and data filesystems.

The examples assume two identical harddrives, sda and sdb, on which after a small boot partition, 1 GB is used for swap, 25 GB is used for the root filesystem and everything else is for a big "data" partition that will hold non-system stuff.

Although I personally prefer /boot to be readonly, this guide doesn't add the ro flag in /etc/fstab, because that'll only lead to complaints about lilo upgrades not going smoothly. (Which is exactly the point of having it readonly in the first place...)

They also assume some specific tools that you may or may not like, and a kernel without module support. This is how I prefer to do things for servers. Please don't try to persuade me to use kernel packages, grub, modules, or whatever.

General knowledge is required. Don't begin unless you understand each step.

If you want to print this, use the printable version.

Raidthingy

The 42nd time you do all this, it gets rather boring. So I decided to automate steps 4..19, excluding 15 (kernel), using a simple Perl script.

This script assumes you have equal and empty (unpartitioned) drives, and provides very little flexibility.

wget http://juerd.nl/files/raidthingy.pl vim raidthingy.pl # Learn what it does. perl raidthingy.pl # Follow instructions 

The guide

1. Get a bootable cd with debootstrap and RAID support, like KNOPPIX, and boot from it.

2. Find a root shell.

If your drives are hdx instead of sdx, ensure that DMA is enabled for both drives:

hdparm -d1 /dev/hda hdparm -d1 /dev/hdc 

The rest of this guide assumes sda and sdb, because S-ATA devices are presented as SCSI devices in recent kernels.

3. Get networking up and running, if you don't have DHCP:

ifconfig eth0 123.123.123.123 up route add default gw 123.123.123.1 echo nameserver 123.123.123.1 > /etc/resolv.conf 

4. Partition the drives, paying no attention to partition types yet:

fdisk /dev/sda # n <CR> p <CR> 1 <CR> <CR> +64M <CR> # n <CR> p <CR> 2 <CR> <CR> +1G <CR> # n <CR> e <CR> 3 <CR> <CR> <CR> # n <CR> l <CR> <CR> +25G <CR> # n <CR> l <CR> <CR> <CR> # a <CR> 1 <CR> w <CR> fdisk /dev/sdb # n <CR> p <CR> 1 <CR> <CR> +64M <CR> # n <CR> p <CR> 2 <CR> <CR> +1G <CR> # n <CR> e <CR> 3 <CR> <CR> <CR> # n <CR> l <CR> <CR> +25G <CR> # n <CR> l <CR> <CR> <CR> # a <CR> 1 <CR> w <CR> 

5. For every partition, create a RAID 1 array:

mdadm --create /dev/md0 -n 2 -l 1 /dev/sda1 /dev/sdb1 mdadm --create /dev/md1 -n 2 -l 1 /dev/sda2 /dev/sdb2 mdadm --create /dev/md2 -n 2 -l 1 /dev/sda5 /dev/sdb5 mdadm --create /dev/md3 -n 2 -l 1 /dev/sda6 /dev/sdb6 

If you plan on installing sdb later, use missing instead of the second device.

For RAID 5, use -l 5 instead of -l 1, and just specify more disks. Make sure the boot volume is RAID 1, not 5 (/dev/md0 here, and yes, you can have RAID 1 with more than 2 disks). Also, increase the number of disks (-n) accordingly.

6. Create filesystems and initialize swap space:

mkfs.ext3 /dev/md0 mkswap /dev/md1 mkfs.ext3 /dev/md2 mkfs.ext3 /dev/md3 -O dir_index 

7. Create a target mountpoint and mount your new filesystem(s) there:

mkdir /target mount /dev/md2 /target mkdir /target/boot mount /dev/md0 /target/boot mkdir /target/data mount /dev/md3 /target/data mkdir /target/data/home mkdir /target/home mount --bind /target/data/home /target/home mkdir /target/data/var mkdir /target/var mount --bind /target/data/var /target/var mkdir /data/share # for samba shares mkdir /data/www # for mod_vhost_alias sites 

8. Install a basic Debian system using debootstrap:

debootstrap sarge /target http://ftp.nl.debian.org/debian

9. Delete symlinks to the outside world in the target's etc:

cd /target/etc rm hostname resolv.conf localtime 

10. Get some real things there:

cp /etc/resolv.conf . ln -s /usr/share/zoneinfo/Europe/Amsterdam localtime echo newboxthingy > hostname vim default/rcS # FSCKFIX=yes 

11. Set up the file system table:

# This is /etc/fstab /dev/md0 /boot ext3 defaults 0 1 /dev/md1 none swap swap /dev/md2 / ext3 defaults,errors=remount-ro 0 1 /dev/md3 /data ext3 defaults,errors=remount-ro 0 1 /data/home /home bind bind /data/var /var bind bind proc /proc proc 

12. Get a working sources.list:

cd apt rm sources.list wget http://juerd.nl/sources.list 

13. Change the current root directory to enter the new system:

chroot /target

14. Get the system up to date and install some useful packages:

apt-get update apt-get dist-upgrade apt-get install less wget w3m vim libncurses5-dev make gcc mbr bzip2 lilo mdadm ssh 

When asked to start RAID arrays automatically, answer "No", as this is not needed with RAID built into the kernel and autodetected arrays.

15. Download a kernel, configure it, compile it, copy it:

cd /usr/src wget http://ftp.nl.kernel.org/pub/linux/kernel/v2.6/linux-2.6.12.tar.bz2 tar -jvxf linux-2.6.12.tar.bz2 ln -s linux-2.6.12 linux # grsecurity (optional) wget http://www.grsecurity.net/grsecurity-2.1.6-2.6.11.12-200506141713.patch.gz cd linux zcat ../grsecurity-2.1.6-2.6.11.12-200506141713.patch.gz | patch -p1 cd /usr/src/linux make menuconfig # Don't forget to compile in RAID 1/5 and ext3 support. make bzImage cp arch/i386/boot/bzImage /boot/vmlinuz-2.6.11.9 cp System.map /boot/System.map-2.6.11.9 

16. Configure LILO:

# This is /etc/lilo.conf boot=/dev/md0 root=/dev/md2 compact lba32 read-only image=/boot/vmlinuz-2.6.11.9 label=Linux 

17. Install the boot records:

lilo install-mbr /dev/sda install-mbr /dev/sdb 

18. Configure networking:

# This is /etc/network/interfaces auto lo iface lo inet loopback auto eth0 iface eth0 inet static address 123.123.123.123 netmask 255.255.255.0 gateway 123.123.123.1 network 123.123.123.0 broadcast 123.123.123.255 # Alternatively: # iface eth0 inet dhcp 

19. Secure things a little:

shadowconfig on passwd adduser foo 

20. Exit the chrooted environment:

exit

21. Wait until synchronization is complete:

watch cat /proc/mdstat

22. Set the partition types to 0xFD:

fdisk /dev/sda # t <CR> 1 <CR> fd <CR> # t <CR> 2 <CR> fd <CR> # t <CR> 5 <CR> fd <CR> # t <CR> 6 <CR> fd <CR> w <CR> fdisk /dev/sdb # t <CR> 1 <CR> fd <CR> # t <CR> 2 <CR> fd <CR> # t <CR> 5 <CR> fd <CR> # t <CR> 6 <CR> fd <CR> w <CR> 

23. Reboot and bring your favourite god(s) sacrifices:

reboot

24. Consider donating:

• Software in the Public Interest, Inc. (Debian)
• Free Software Foundation (GNU)
• Apache Software Foundation
• Perl Development Fund