Remote conversion of 64-bit CentOS 6.5 to 64-bit Ubuntu 14.04
For 32-bit source to 64-bit see my older post.
Old install was using software RAID-1, but did not have LVM. Small 200MB /boot partition, 8GB swap and rest as one root partition. We're redoing it completely so what it used to be doesn't really matter. All existing data on root will be lost.
Old install was using software RAID-1, but did not have LVM. Small 200MB /boot partition, 8GB swap and rest as one root partition. We're redoing it completely so what it used to be doesn't really matter. All existing data on root will be lost.
# Mark /dev/sda as failed mdadm /dev/md0 --fail /dev/sda1 mdadm /dev/md1 --fail /dev/sda2 mdadm /dev/md2 --fail /dev/sda3 # Drop /dev/sda from RAID-1 mdadm /dev/md0 --remove /dev/sda1 mdadm /dev/md1 --remove /dev/sda2 mdadm /dev/md2 --remove /dev/sda3 # /dev/sda is now free and we can start setting up new install on it
# Install parted if not already there
yum -y install parted
# This is old server and small 250GB disks so we don't use EFI partitions
# 4GB boot, 32GB swap, rest as root - with mdraid of course
parted -s -a optimal /dev/sda \
mklabel msdos \
mkpart primary 4MiB 4GiB \
set 1 raid on \
set 1 boot on \
mkpart primary 4GiB 36GiB \
set 2 raid on \
mkpart primary 36GiB 100% \
set 3 raid on \
print
# Create mdraid in degraded mode
echo y|mdadm --create /dev/md101 --force --assume-clean --level=1 --raid-devices=2 \
--homehost foobar --name=foobar_rp_boot --bitmap=internal \
missing /dev/sda1
echo y|mdadm --create /dev/md102 --force --assume-clean --level=10 --raid-devices=2 \
--homehost foobar --name=foobar_rp_swap --bitmap=internal \
missing /dev/sda2
echo y|mdadm --create /dev/md103 --force --assume-clean --level=10 --raid-devices=2 \
--homehost foobar --name=foobar_rp_root --bitmap=internal \
missing /dev/sda3
# Create filesystems mkfs.ext4 -L"foobar_boot" /dev/md101 mkswap -f -L"foobar_swap" /dev/md102 mkfs.ext4 -L"foobar_root" /dev/md103
# Next we get to debootstrap part to actually install something
# Mount new root + boot filesystems and prepare for debootstrap process
mkdir -p /newsys
mount /dev/md103 /newsys
mkdir -p /newsys/boot
mount /dev/md101 /newsys/boot
# Download and install Ubuntu keyring and debootstrap in case we're not running Ubuntu yet
mkdir -p /tmp/debootstrap
cd /tmp/debootstrap
wget http://archive.ubuntu.com/ubuntu/pool/main/u/ubuntu-keyring/ubuntu-keyring_2011.11.21.1.tar.gz
#
# Check md5sum - cfa87364720b96e5ca15ef7b2cb4c948
md5sum ubuntu-keyring_2011.11.21.1.tar.gz
# If it matches unpack
tar xzf ubuntu-keyring_2011.11.21.1.tar.gz
#
wget http://archive.ubuntu.com/ubuntu/pool/main/d/debootstrap/debootstrap_1.0.66_all.deb
#
# Check md5sum - 040f3afe15b2b6dd953df6eb2091562f
md5sum debootstrap_1.0.66_all.deb
#
# Unpack and install
ar -x debootstrap_1.0.66_all.deb
tar xzf data.tar.gz -C /
# Many packages required won't work if installad as part of debootstrap so we don't do so
debootstrap --keyring=/tmp/debootstrap/ubuntu-keyring-2011.11.21.1/keyrings/ubuntu-archive-keyring.gpg \
--include=dosfstools --arch=amd64 trusty /newsys http://fi.archive.ubuntu.com/ubuntu/
# Mount proc, sysfs and dev required for next steps mount -t proc proc /newsys/proc mount -t sysfs sys /newsys/sys mount -o bind /dev /newsys/dev mount -t devpts pts /newsys/dev/pts # We need mtab, but copying /proc/mounts will cause problems so hack a bit.. cat /etc/mtab | grep /newsys | sed -e's|/newsys|/|g' -e's|//|/|g' > /newsys/etc/mtab
# chroot to new install to continue LANG= chroot /newsys /bin/bash # Create missing mdraid device links mkdir -p /dev/md ln -s /dev/md101 /dev/md/foobar_rp_boot ln -s /dev/md102 /dev/md/foobar_rp_swap ln -s /dev/md103 /dev/md/foobar_rp_root # Create fstab for our new install echo "UUID=$(blkid -t LABEL=foobar_root -s UUID -o value) / ext4 defaults,noatime,discard,errors=remount-ro 0 1" >/etc/fstab echo "UUID=$(blkid -t LABEL=foobar_boot -s UUID -o value) /boot ext4 defaults,noatime,discard,nobootwait,nofail 0 2" >>/etc/fstab echo "UUID=$(blkid -t LABEL=foobar_swap -s UUID -o value) swap swap defaults,discard 0 2" >>/etc/fstab
# Set hostname echo "foobar" >/etc/hostname # Also update hosts file to prevent warnings from sudo etc. cat<<'__EOF__'>/etc/hosts 127.0.0.1 localhost 127.0.0.1 foobar foobar.example.com ::1 ip6-localhost ip6-loopback fe00::0 ip6-localnet ff00::0 ip6-mcastprefix ff02::1 ip6-allnodes ff02::2 ip6-allrouters ff02::3 ip6-allhosts __EOF__ # Setup static IP for network cat<<'__EOF__'>/etc/network/interfaces auto lo iface lo inet loopback auto eth0 iface eth0 inet static address 10.16.104.13 network 10.16.104.0 broadcast 10.16.104.255 gateway 10.16.104.1 netmask 255.255.255.0 __EOF__ # DNS too cat<<'__EOF__'>/etc/resolv.conf options timeout:2 attempts:2 rotate nameserver 8.8.8.8 nameserver 8.8.4.4 nameserver 74.82.42.42 nameserver 208.67.222.222 __EOF__
# Ugly hack to prevent launching of services while setting up system with apt-get mkdir -p /tmp/fakestart ln -s /bin/true /tmp/fakestart/initctl ln -s /bin/true /tmp/fakestart/invoke-rc.d ln -s /bin/true /tmp/fakestart/restart ln -s /bin/true /tmp/fakestart/start ln -s /bin/true /tmp/fakestart/stop ln -s /bin/true /tmp/fakestart/start-stop-daemon ln -s /bin/true /tmp/fakestart/service export PATH=/tmp/fakestart:$PATH
# Enable full repositories, we need for example dropbear not included in main repos
cat <<'__EOF__'>/etc/apt/sources.list
deb http://fi.archive.ubuntu.com/ubuntu/ trusty main restricted
deb-src http://fi.archive.ubuntu.com/ubuntu/ trusty main restricted
deb http://fi.archive.ubuntu.com/ubuntu/ trusty-updates main restricted
deb-src http://fi.archive.ubuntu.com/ubuntu/ trusty-updates main restricted
deb http://fi.archive.ubuntu.com/ubuntu/ trusty universe
deb-src http://fi.archive.ubuntu.com/ubuntu/ trusty universe
deb http://fi.archive.ubuntu.com/ubuntu/ trusty-updates universe
deb-src http://fi.archive.ubuntu.com/ubuntu/ trusty-updates universe
deb http://fi.archive.ubuntu.com/ubuntu/ trusty multiverse
deb-src http://fi.archive.ubuntu.com/ubuntu/ trusty multiverse
deb http://fi.archive.ubuntu.com/ubuntu/ trusty-updates multiverse
deb-src http://fi.archive.ubuntu.com/ubuntu/ trusty-updates multiverse
deb http://fi.archive.ubuntu.com/ubuntu/ trusty-backports main restricted universe multiverse
deb-src http://fi.archive.ubuntu.com/ubuntu/ trusty-backports main restricted universe multiverse
deb http://security.ubuntu.com/ubuntu trusty-security main restricted
deb-src http://security.ubuntu.com/ubuntu trusty-security main restricted
deb http://security.ubuntu.com/ubuntu trusty-security universe
deb-src http://security.ubuntu.com/ubuntu trusty-security universe
deb http://security.ubuntu.com/ubuntu trusty-security multiverse
deb-src http://security.ubuntu.com/ubuntu trusty-security multiverse
__EOF__
# Prevent apt-get from asking silly questions
export DEBIAN_FRONTEND=noninteractive
# Fix DNS resolution issues for good by removing root cause
# This package is stubborn and can't be excluded during deboostrap
apt-get -y remove resolvconf
# Install some more or less mandatory packages
apt-get update
apt-get --no-install-recommends -y install openssh-server mdadm locales gdisk parted nano \
linux-image-generic grub-pc-bin grub2-common
# Set root password passwd root # Allow root over ssh because we're professionals sed -i.bak -e's/.*PermitRootLogin.*/PermitRootLogin yes/g' /etc/ssh/sshd_config
# Zap partitions on /dev/sdb so it doesn't cause issues on next boot
# This will give error because there's active mdraid on sdb, but don't worry
sgdisk -Z /dev/sdb
# Create devicemap for grub (/boot/grub/device.map)
mkdir -p /boot/grub
grub-mkdevicemap -nvv
# Install grub boot sector to both disks
# This will prevent old os from booting but otherwise there's
# risk of bios picking wrong disk to boot from
grub-install --target=i386-pc /dev/sda
grub-install --target=i386-pc /dev/sdb
# Silent boot is nonsense causing nothing but trouble
#
# This will change kernel parameters to be more verbose, try to allow boot with degraded RAID,
# and also enables on-the-fly compression for swap
#
# I have feeling that some of these are no longer valid parameters (if they ever were) due
# constant battle between developers breaking things and users trying to find workarounds to
# those unwanted changes...
#
sed -i.bak -e's|^GRUB_CMDLINE_LINUX_DEFAULT=.*|GRUB_CMDLINE_LINUX_DEFAULT="verbose bootdegraded=true bootwait=5 zswap.enabled=1 zswap.compressor=lz4"|g' \
-e's|^GRUB_HIDDEN_|#GRUB_HIDDEN_|g' /etc/default/grub
#
# Workaround for diskfilter write error with GRUB and mdraid
sed -i -e's|^quiet_boot="1"|quiet_boot="0"|g' -e's|^quick_boot="1"|quick_boot="0"|g' /etc/grub.d/10_linux
#
# More fixes
cat<<'__EOF__'>>/etc/default/grub
GRUB_SAVEDEFAULT=n
GRUB_TERMINAL_OUTPUT=console
GRUB_TERMINAL=console
GRUB_DISABLE_RECOVERY=y
GRUB_DISABLE_SUBMENU=y
GRUB_DISABLE_OS_PROBER=y
GRUB_GFXPAYLOAD=text
GRUB_GFXPAYLOAD_LINUX=keep
__EOF__
# Ubuntu initramfs is not able to handle degraded RAID arrays. I'm aware of all sorts
# of "magic" parameters one can set but if you look inside what initramfs scripts do
# they don't even check for those settings or try to do anything smart when there's error.
#
# What we do below is force arrays online even if some disks are missing. It's far better
# to bring system up in such case and let admin sort it out. Other option is dropping
# to initramfs shell and taking all down for good. Morons...
#
# As usual one more hack. Not that it should do anything bad because md arrays can't be
# taken down if they already came up ok. If they didn't by time this script is run
# it's game over without this.
#
cat >/usr/share/initramfs-tools/scripts/init-premount/zzmdraidtryharder <<'__EOF__'
#!/bin/sh
PREREQ=""
prereqs() {
echo "$PREREQ"
}
case "$1" in
prereqs)
prereqs
exit 0
;;
esac
. /scripts/functions
sleep 15
echo ""
echo ""
echo "Before fix mdraid status from /proc/mdstat"
cat /proc/mdstat
echo ""
echo "Force-starting arrays with missing or unsynced disks (if any)"
echo""
echo ""
mdadm --misc --run /dev/md*
echo ""
echo "After fix mdraid status from /proc/mdstat"
cat /proc/mdstat
echo ""
sleep 5
__EOF__
# Make it executable
chmod a+x /usr/share/initramfs-tools/scripts/init-premount/zzmdraidtryharder
# Rebuild initramdisk so it includes our mdraid fix
update-initramfs -c -k all
# Update grub.cfg update-grub # Exit chroot and reboot exit reboot
# Prevent apt-get from asking silly questions
export DEBIAN_FRONTEND=noninteractive
# Update distro, install common tools and some extra packages
apt-get update
apt-get -y dist-upgrade
apt-get -y install ubuntu-standard joe wget curl screen python perl mtr traceroute \
language-pack-en fail2ban boot-info-script i7z sysstat \
build-essential python-software-properties software-properties-common \
linux-source linux-headers-generic smartmontools ntp lftp
# Set locale update-locale LANG=en_US.UTF-8 LANGUAGE=en_US # Set timezone cp -f /usr/share/zoneinfo/Europe/Helsinki /etc/localtime echo "Europe/Helsinki" >/etc/timezone # Set keyboard layout sed -i.bak -e's|^XKBLAYOUT=.*|XKBLAYOUT="fi"|g' /etc/default/keyboard dpkg-reconfigure keyboard-configuration dpkg-reconfigure console-setup
# Create regular user account, allow sudo, set password adduser viidakongeorge --shell /bin/bash --disabled-password --gecos viidakongeorge usermod -a -G sudo viidakongeorge passwd viidakongeorge
# Always prefer IPv4 over IPv6 due suboptimal IPv6 routing and peering echo "precedence ::ffff:0:0/96 100" >>/etc/gai.conf
# We still need to add our second disk as part of mirror
# Partitions
parted -s -a optimal /dev/sdb \
mklabel msdos \
mkpart primary 4MiB 4GiB \
set 1 raid on \
set 1 boot on \
mkpart primary 4GiB 36GiB \
set 2 raid on \
mkpart primary 36GiB 100% \
set 3 raid on \
print
# RAID, we can use labels now mdadm --manage /dev/md/foobar_rp_boot --add /dev/sdb1 mdadm --manage /dev/md/foobar_rp_swap --add /dev/sdb2 mdadm --manage /dev/md/foobar_rp_root --add /dev/sdb3
# Make sure grub is happy with all that has been changed # Create devicemap for grub (/boot/grub/device.map) mkdir -p /boot/grub grub-mkdevicemap -nvv # Install grub boot sector to both disks grub-install --target=i386-pc /dev/sda grub-install --target=i386-pc /dev/sdb # Rebuild initramdisk update-initramfs -c -k all # Update grub.cfg update-grub # Reboot to be sure everything works in future as well reboot
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