1. Write Down the root Password.
Yes, this is a bad security practice. Yes, do it anyway. Keep a highly-protected notebook, reverse or scramble the password, use simple encryption (letter-shift and number-shift three letters or numbers to the left or right, for instance) – choose a method of keeping this information secure, but keep this information available. You will forget this someday.
2. Write Down Your Partition Layout.
Command:
fdisk -l /dev/hda #assuming your hard disk is hda
and write this information down on paper. You want all of it:
- the device label,
- whether it’s the boot partition,
- the starting and ending sectors,
- the total size,
- the filesystem type ID,
- and the system type of each partition.
3. Copy the Partition Table.
First, write the table information down. Command:
cat /etc/fstab
Capture every bit of this information. Yes, every single letter.
Next, take an electronic copy of the partition table. Let’s assume you’re using a USB drive. Mount it using something like this:
mount -t fat32 /dev/sda /mnt/custom
Then capture the partition table:
sfdisk -d /dev/sda > /mnt/custom/ptable.bak
Later you can restore it with:
sfdisk /dev/sda < /mnt/custom/ptable.bak
4. Write Down the Distro and Version.
Sure, you know this now. Will you later? Be doubtful.
5. Print out any instructions that come with your distro or its recovery disk.
6. Back Up Critical Directories
Obviously you want to back up /home, but you should also back up /boot, especially if you use GRUB.
Use the mkbootdisk command with the kernel name as the argument. Obviously you must have this kernel on your system:
uname -r #tells you which kernel you’re running
mkbootdisk 2.4.21-20 #use the version number from the above