Remote install of a Linux Distro on top of an exsiting distro
I stumbled across this as a result of a thread on Experts Exchange (http://www.experts-exchange.com/OS/Linux/Distributions/Red_Hat/Q_24539260.html?cid=359) and it made for fantastic reading, just highlighting what can be possible if the need ever arises to do a remote secure wipe of a server. This can be achieved by installing an OS by using the /swap partition as /
Many thanks to Emma Jane Hogbin for this. I’ve copied the notes here purely in case of the original found here being deleted.
A very long time ago I leased some server space that had RedHat and I wanted Debian. So I did a remote install using the /swap partition as a / partition. I thought the notes were lost, but I found them. I include them here for historical (hysterical?) purposes only.
# One hundred thank yous to Azhrarn and Karsten.
# Their HOWTOs and personal support were infinitely useful
# http://twiki.iwethey.org/Main/DebianChrootInstall by Karsten
# http://trilldev.sourceforge.net/files/remotedeb.html by Azhrarn (Erik Jacobson)
# ~ emma jane hogbin# First grab the base system that you’re going to be using
# wget -q http://archive.debian.org/dists/Debian-2.2/main/disks-i386/current/base2…# Make sure you have the full archive
# md5sum base2_2.tgz
# should give: 8010d9f0467ebbb54d89ac84261cb696# Install debootstrap
rpm -ivh http://azhrarn.underhanded.org/debootstrap-0.2.23-1.i386.rpm# output of /sbin/lsmod
ipt_state 1080 0 (autoclean)
ipt_REJECT 3992 0 (autoclean)
ipt_LOG 4184 0 (autoclean)
ipt_limit 1560 0 (autoclean)
iptable_filter 2412 0 (autoclean)
ip_tables 15096 5 [ipt_state ipt_REJECT ipt_LOG ipt_limit iptable_filter]
ip_conntrack_ftp 5296 0 (autoclean) (unused)
ip_conntrack 27272 2 (autoclean) [ipt_state ip_conntrack_ftp]
autofs 13268 0 (autoclean) (unused)
8139too 18120 1
mii 3976 0 [8139too]
keybdev 2976 0 (unused)
mousedev 5556 0 (unused)
hid 22244 0 (unused)
input 5856 0 [keybdev mousedev hid]
ehci-hcd 20072 0 (unused)
usb-uhci 26412 0 (unused)
usbcore 79040 1 [hid ehci-hcd usb-uhci]
ext3 70784 2
jbd 51924 2 [ext3]# figure out some information about your current setup
# ssh in to your machine and check the network information with
/sbin/ifconfig# You’ll need the following information from the output
# eth0 will have a line that starts with “inet…”
inet addr:66.98.212.88 Bcast:66.98.213.255 Mask:255.255.254.0# Partition the harddrive to match the above configuration
su
mkdir /mnt/debinstall# try working out of swap instead
/sbin/swapoff -a
/sbin/fdisk /dev/hda
p # look at the list of partitions
t # change the type
2 # of swap
83 # to regular linux
w # write and quit
/sbin/mke2fs /dev/hda2 # convert the partition to ext2 — do not use ext3
/sbin/tune2fs -O ^dir_index /dev/hda2 # from remotedb.html on sf# edit the /etc/fstab file to change the /swap partition to
# /mnt/debinstall
/etc/fstab
/dev/hda3 / ext3 defaults 1 1
/dev/hda1 /boot ext3 defaults 1 2
none /dev/pts devpts gid=5,mode=620 0 0
none /proc proc defaults 0 0
none /dev/shm tmpfs defaults 0 0
/dev/hda2 /mnt/debinstall ext2 defaults 1 1# NB this is how big they have their partitions
[root@plain root]# df -h
Filesystem Size Used Avail Use% Mounted on
/dev/hda5 71G 1.4G 66G 3% /
/dev/hda1 99M 15M 80M 16% /boot
/dev/hda3 1012M 33M 928M 4% /tmp
none 247M 0 247M 0% /dev/shm# reboot the system
reboot# on the reboot the /swap partition should now be mounted as the new
# partition. Double check to see that it’s actually working though
df # confirm that it’s actually mounted
#cd /mnt/debinstall
# su
#cp /home/admin/base2_2.tgz .# unpack the base system
#gunzip base2_2.tgz
#tar -xvf base2_2.tar# install the base system
/usr/sbin/debootstrap –arch i386 woody /mnt/debinstall http://http.us.debian.org/debian# copy over the important config files
# according to remotedeb.html
cp /etc/resolv.conf etc/resolv.conf
cp /etc/hosts etc/hosts
cp /etc/fstab etc/fstab# the default EV1 server does not have an /etc/hostname
hostname xtrinsic.net # sets the host name
hostname –fqdn # tests to see if it’s set# configure network stuff
# this can be done either from the original system or the new one
route -nKernel IP routing table
Destination Gateway Genmask Flags Metric Ref Use Iface
66.98.212.0 0.0.0.0 255.255.254.0 U 0 0 0 eth0
169.254.0.0 0.0.0.0 255.255.0.0 U 0 0 0 eth0
127.0.0.0 0.0.0.0 255.0.0.0 U 0 0 0 lo
0.0.0.0 66.98.212.1 0.0.0.0 UG 0 0 0 eth0# enter into chroot.
/usr/sbin/chroot . bin/bash# the prompt has now changed to:
xtrinsic:/## vi is installed but won’t run because it doesn’t know the term type
# set that now with:
export TERM=vt100
export PATH=/usr/local/sbin:/usr/sbin/:/sbin:/usr/bin:/binxtrinsic:/# cat > /etc/fstab << “EOF”
> # filesystem mount-point fs-type options dump fsck-order
> /dev/sda5 / auto defaults 0 1
> proc /proc proc defaults 0 0
> EOF# mount proc
mount -t proc proc /proc# edit the following files
etc/resolv.conf # should be ok because it was cped from RedHat
etc/network/interfaces # this will be a new file and should have the following——— /etc/network/interfaces ———
# the loopback interface
auto lo
iface lo inet loopback# the first (and only) network card
auto eth0
iface eth0 inet static
# 1st from ifconfig
address 66.98.212.88
# 3rd from ifconfig
netmask 255.255.254.0
# 1st from route -n
network 66.98.212.0
# 2nd from ifconfig
broadcast 66.98.213.255
# last line, 2nd column of route -n
gateway 66.98.212.1
——————————————–# run the base configuration
/usr/sbin/base-configyes # gmt
Canada EST # time zone# next configure the base system
# this worked the first time (i.e. Server V. 1), but refused to work the
# second time (citing nmap running out of space, or something). I tried
# increasing the Cache in /etc/apt/apt.conf but it didn’t work
# dpkg-reconfigure –install base-config
# the rest of the questions
No # md5 passwords
Yes # shadow passwords
root password
Yes # new userYes # Remove pcmcia
no # PPP
simple # for how to install software
# then wait for it to chug a bit
http # method for installing
yes # non-free
yes # non-us
yes # contrib
[pick a mirror]
<blank> # no proxy to get out
[get ready to install some stuff, yes to security updates]
no # taskel to install new softwaredialog # for installing
medium # for questions
no # readable home directories
ask # about PCMCIA card when installing new things
yes # start support after install
american # spelling stuff
no locales # for now
leave alone # default locale
auto save once # type of automatic serial port configuration
yes # upgrade glibc nowapt-get install netselect wget
cd /etc/apt; netselect-apt woody
echo “deb http://security.debian.org stable/updates main contrib non-free” >> /etc/apt/sources.list# install a few more packages
apt-get install aptitude screen ssh vim gpw# config options
Allow only SSH2? YesDo you want /usr/lib/ssh-keysign to be installed SUID root? Yes # default
Run the sshd server? Yes # defaultdefault # all exim stuff (to be replaced by postfix)
# utility to see what modules you need loaded
apt-get install discover
discover –enable-all –format=”%m on %d – %V %M\n” bridge ide scsi usb ethernet
xtrinsic:/# discover –format=”%m on %d – %V %M\n” bridge ide scsi usb ethernet
discover: Bus not found.# edit the modutils file and add the ethernet stuff
vi /etc/modutils/aliases
alias eth0 8139too
update-modules# remove the /sbin/unconfigured.sh file
# rm /sbin/unconfigured.sh — didnt’ exist# run the base-config again, there are other options you don’t have yet
base-config
# edit the apt.sources list by hand and don’t run any other software stuff
# don’t run taskel, and don’t run dselect# configure the discover bit
vi /etc/discover.conf
———————
# Enable the PCMCIA scan
# accorinding to remotedb.html
skip=”pcmcia rtl8139″
# Scan for the following types of hardware at boot time:
types=”boot bridge ethernet ide scsi usb”
——————–# install a new kernel with patches for various security things
# apt-get install kernel-image-2.4.18-1-686
apt-get install kernel-image-2.4.27-2-686
Ignore error messages about initrd (answer “no”)
Create the link, when it asks
Do NOT do anything that lilo asks you about# make sure the right devices are in place for the kernel/system
cd /dev
./MAKEDEV generic # wait patiently, this may take a minute# exit the chroot environment
exit# copy over the new kernel (you should still be root)
cp /mnt/debinstall/boot/vmlinuz-2.4.18-1-686 /boot/.
cp /mnt/debinstall/boot/initrd.img-2.4.18-1-686 /boot/.# edit /etc/lilo.conf and add the following information
——————-
default=redhat
image=/boot/vmlinuz-2.4.18-1-686
label=Debian
initrd=/boot/initrd.img-2.4.18-1-686
read-only
append=”panic=30″
——————–# copy the new lilo over to the /mnt/debinstall
cp /etc/lilo.conf /mnt/debinstall/etc/lilo.conf
# make sure all kernels which are listed in /etc/lilo.conf are in the new /boot
cp $(grep “image.*=” /etc/lilo.conf | cut -f 2 -d “=”) /mnt/debinstall/boot# -R means use the specified image only for the next boot
# therefore if the system panics it will reboot into redhat
/sbin/lilo -v
/sbin/lilo -v -R Debiantouch /mnt/debinstall/fastboot
# and finally — reboot
# wait at least 5-10 minutes before trying to log back in again
# remember to try the new accounts first and the old accounts second
# and remember to delete your old SSH authentication key from teh old username
reboot# After getting the remote install working, I moved onto post install
# configuration. I started out by adding the following packages:
apt-get install mysql-server php4 php4-mysql apache postfix lynx
(postfix replaces exim)# to reset the hostname I edited /etc/hostname and added my domain name
# I then reset the hostname with hostname <domainname> and checked it with
# hostname –fqdn “fully qualified domain name”# A very weird thing has happened. I appear to be running an OS off of a
# partition that isn’t mounted.
emmajane@(none):/$ df -h
Filesystem Size Used Avail Use% Mounted on
/dev/hda3 1.9G 226M 1.6G 13% /
/dev/hda1 99M 13M 81M 14% /bootemmajane@(none):/$ more /etc/fstab
/dev/hda3 / ext3 defaults 1 1
/dev/hda1 /boot ext3 defaults 1 2
none /dev/pts devpts gid=5,mode=620 0 0
none /proc proc defaults 0 0
none /dev/shm tmpfs defaults 0 0
/dev/hda2 /mnt/debinstall ext2 defaults 1 1emmajane@(none):/$ more /etc/lilo.conf
image=/boot/vmlinuz-2.4.18-1-686
label=debian-2418
initrd=/boot/initrd.img-2.4.18-1-686
read-only
append=”panic=30″
root=/dev/hda2My debian is calling itself /dev/hda3 for some reason, when really it’s hda2
xtrinsic:/# more /etc/lilo.conf
prompt
timeout=50
default=debian
boot=/dev/hda
map=/boot/map
install=/boot/boot.b
message=/boot/message
linearimage=/boot/vmlinuz-2.4.18-1-686
label=debian
initrd=/boot/initrd.img-2.4.18-1-686
read-only
root=/dev/hda2
append=”panic=30″image=/boot/vmlinuz-2.4.20-24.9
label=redhat
initrd=/boot/initrd-2.4.20-24.9.img
read-only
append=”root=/dev/hda3″xtrinsic:/# lilo -v
LILO version 22.2, Copyright (C) 1992-1998 Werner Almesberger
Development beyond version 21 Copyright (C) 1999-2001 John Coffman
Released 05-Feb-2002 and compiled at 20:57:26 on Apr 13 2002.
MAX_IMAGES = 27Reading boot sector from /dev/hda
Merging with /boot/boot.b
Fatal: First boot sector is version 21.4. Expecting version 22.2.http://software.cfht.hawaii.edu/linuxpc/sidious/6_Kernel_Options.html
Change the line which refers to /boot/boot.b to /boot/boot-menu.bNow the boot-menu.b file is “missing” though because it’s in
/deb/mntinstall/boot, not in /boot. This will need fixing. There appear
to be instructions in remotedeb.htmlapt-get install man less
export TERM=vt1000. backup /boot to a very safe place
1. comment out the /boot partition from /etc/fstab
change your debian install directory to /mnt/tmp (instead of /mnt/deb..)
comment out the old data partition (/dev/hda3)
2. mount /mnt/tmp
3. the new boot information should now be in /mnt/tmp/boot/
pack it up with tar and copy it to the / directory
4. umount /mnt/tmp
5. unpack the contents into /boot-deb
6. edit lilo.conf and change boot to boot-deb
7. run lilo (expect errors) this seems to have cleared out /boot
8. copy boot-deb to /boot and add back any files from your backup of
/boot (for me it was message and the red hat images)
9. edit lilo.conf again and change /boot-deb back to /boot. To be safe, leave
redhat as the default for now and leave the panic set on debian and set lilo
to lilo -v -R debian (reboot into debian only this once)
10. Now you should be able to run lilo
11. Quadruple check your /etc/fstab to make sure it has the right values.
Values should be updated according to the instructions above (but not the
sample /etc/fstab which is way above)
12. as long as there are no errors, reboot# Re-partition the old data drive
# in the end I decided not to use parted and stuck with good ol’ cfdisk
apt-get install cfdisk # it was already installed# do the actual partitioning
cfdisk /dev/hda
# cfdisk is just a nicer interface for fdisk
# replace /dev/hda3 with smaller logical partitions
select /dev/hda3
d # delete it# Now create all of your new partitions
n # create a new partition
L # for logical
<size in megs> # used the sizes below for each of the partitions
B # add the new partition to the beginning of the free space2000 /usr/local /dev/hda5
10000 /var /dev/hda6
# users shouldn’t be storing email on
# the server
500 /swap /dev/hda7
t # change the type
82 # linux swap
300 /tmp /dev/hda8 # bigger than required
5000 /home /dev/hda9 # most data will be in /web
500 /config /dev/hda10 # a safe place for config files
5000 /cvsroot /dev/hda11 # cvs repository
40000 /var/www /dev/hda12 # all web sites
[~ 14Gigs left open to assign as necessary]# write this new partition table
# note: I got this error message:
Wrote partition table, but re-read table failed. Reboot to update
table.# quit and reboot the system–remember to give the system a minute or two
# to reboot# format the partitions and add labels for each of the partitions
# while you’re at it, add a label for the / partition
e2label /dev/hda2 /
mkfs.ext2 /dev/hda5
e2label /dev/hda5 /usr/local
mkfs.ext2 /dev/hda6
e2label /dev/hda6 /var
# don’t touch swap
mkfs.ext2 /dev/hda8
e2label /dev/hda8 /tmp
mkfs.ext2 /dev/hda9
e2label /dev/hda9 /home
mkfs.ext2 /dev/hda10
e2label /dev/hda10 /config
mkfs.ext2 /dev/hda11
e2label /dev/hda11 /cvsroot
mkfs.ext2 /dev/hda12
e2label /dev/hda12 /var/www# confirm all of the labels have been added with cfdisk
# “q” without doing anyting to any of the partitions# Now add all of the new partitions to the /etc/fstab file
—————- /etc/fstab ——————————
# Partition table
# make sure there are no trailing slashes on any of the directories
/dev/hda1 /boot ext3 defaults 1 2
/dev/hda2 / ext2 defaults 1 1
/dev/hda5 /usr/local ext2 defaults 0 2
/dev/hda6 /var ext2 defaults 0 2
/dev/hda8 /tmp ext2 defaults 0 2
/dev/hda9 /home ext2 defaults 0 2
/dev/hda10 /config ext2 defaults 0 2
/dev/hda11 /cvsroot ext2 defaults 0 2
/dev/hda12 /var/www ext2 defaults 0 2# swap partition
/dev/hda7 none swap sw 0 0# and then some other stuff that EV1 set up
none /dev/pts devpts gid=5,mode=620 0 0
none /proc proc defaults 0 0
none /dev/shm tmpfs defaults 0 0
———————————————————-# after adding the new partitions, labelling and adding them to the
# /etc/fstab, copy the information to the new partitions
1. archive the information currently in the directory you’re going to
replace
2. delete the contents of the directory
3. mount the directory
4. copy the files back in
5. Activate and mount the /swap partition
mkswap /dev/hda7
swapon -a
sync;sync;sync6. Check the /etc/fstab against what’s currently mounted
7. reboot
Many thanks again to Emma for this fantastic guide.
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