Revantine, The Life and Times

Tigger is a web server with php, perl, mysql, etc.

I unpacked my model…

# cd /xen
# mkdir gopher
# cd gopher/
# tar xjvf ../debian-4.0-20070801.tar.bz2
debian-4.0.img
debian-4.0.xen3.cfg
debian.swap

The original partition layout:

/dev/hda2 on / type ext3 (rw,errors=remount-ro)
/dev/hda1 on /boot type ext3 (rw)
/dev/hdb1 on /home type ext3 (rw,errors=remount-ro)

Filesystem            Size  Used Avail Use% Mounted on
/dev/hda2             2.4G  1.2G  1.2G  51% /
/dev/hda1              45M  9.4M   33M  23% /boot
/dev/hdb1              29G  8.1G   19G  31% /home

I created LVMs and formatted them. This will be the new partition layout.

lvcreate -L1G -n tigger-usr VolGroup00 && \
lvcreate -L10G -n tigger-home VolGroup00 && \
lvcreate -L512M -n tigger-tmp VolGroup00 && \
lvcreate -L2G -n tigger-var VolGroup00 && \
lvcreate -L20G -n tigger-var-www VolGroup00
mkfs -t ext3 /dev/VolGroup00/tigger-usr
mkfs -t ext3 /dev/VolGroup00/tigger-home
mkfs -t ext3 /dev/VolGroup00/tigger-tmp
mkfs -t ext3 /dev/VolGroup00/tigger-var
mkfs -t ext3 /dev/VolGroup00/tigger-var-www

Although right now I have http in /home, I want to move it to /var/www so I will create a partition there large enough to accomodate it. First I will migrate the whole system. After everything works then I will move files around and change configuration. That way I only have one variable at a time.

This is the config file I will use. I just renamed the model and filled in the fields. I used the command from previous to generate a random MAC, leaving the first 3 bytes as the Xen vendor.

dd if=/dev/urandom bs=1 count=3 2>/dev/null | od -tx1 | head -1 | cut -d' ' -f2- | tr -d ' ' | tr '[a-f]' '[A-F]'

/xen/tigger/tigger.cfg

kernel = "/boot/vmlinuz-2.6-xenU"
memory = 512
name = "tigger"
vif = [ 'bridge=xenbr0,mac=00:16:3e:51:9A:81' ]
dhcp = "dhcp"
disk = ['file:/xen/tigger/debian-4.0.img,sda1,w'
, 'file:/xen/tigger/debian.swap,sda2,w'
, 'phy:VolGroup00/tigger-usr,sda3,w'
, 'phy:VolGroup00/tigger-home,sda4,w'
, 'phy:VolGroup00/tigger-tmp,sda5,w'
, 'phy:VolGroup00/tigger-var,sda6,w'
, 'phy:VolGroup00/tigger-var-www,sda7,w'
]
root = "/dev/sda1 ro"
ramdisk = "/boot/initrd-2.6-xenU.img"

I linked the config so it will autostart when owl boots.

ln -s /xen/tigger/tigger.cfg /etc/xen/auto/

And I started the vm

xm create -c tigger.cfg

192.168.0.211

I used the flip script to move the files to the partitions.

./flip sda3 usr
./flip sda6 var

and mounted the empty directories by hand…

mount /dev/sda4 /home
mount /dev/sda5 /tmp
mount /dev/sda7 /var/www
chown www-data:www-data /var/www

Set the IP variable, imported /etc.

export IP='192.168.0.1'
# mkdir ~/etc
cp /etc/mtab ~/etc/ && \
cp /etc/init.d/makedev ~/etc/init.d/ && \
rsync -e ssh -avz root@$IP:/etc/* /etc/ && \
cp -R ~/etc/* /etc/

I remarked out mkdir because I have already created ~/etc in the model vm.

nano /etc/network/interfaces && mkdir -p ~/etc/network && cp /etc/network/interfaces ~/etc/network/

mkdir -p /var/www
rsync -e ssh -avz root@$IP:/var/www/* /var/www/
rsync -e ssh -avz root@$IP:/home/* /home/

To migrate MySQL, I stopped MySQL on the live server and ran

rsync -e ssh -avz $IP:/var/lib/mysql /var/lib/

I will reference my notes here I am sure kanga: Migrating MySQL

Next we are getting the package list from the running server and applying it to this one. In general, take the defaults to NOT change settings.

ssh $IP 'dpkg --get-selections' >~/selections.dpkg && \
apt-get update && \
dpkg --set-selections  < ~/selections.dpkg && \
apt-get dselect-upgrade

I started screen, then ran apt-get dselect-upgrade to start the process. Then I used Ctrl+a d to detach the screen. I can do other things, and disconnect from ssh. When I return I will screen -r to reattach and continue.

If you get “4gb seg fixup” errors, this will probably fix it.

apt-get install libc6-xen
echo "hwcap 0 nosegneg" > /etc/ld.so.conf.d/nosegneg.conf
ldconfig -v -p 2>&1 | grep libc.so
ldconfig

Everything works…
Except Drupal on www.guildplace.org
Ahh, ha! An error about /tmp. I thought I fixed this in the model, but it would appear I did not, or during the filesystem rotation it got broken.

chmod 1777 tmp

This server provides smtp, pop3 and imap. It also provides the ssl versions of these protocols. The old server provided squirrelmail on apache, but I’m not going to impliment that on this server.

The physical server is still running sarge. The vm is running etch. With gopher that jump worked, but this is a much more complex host. I tried deploying gopher across versions and ran in to problems, so I upgraded the physical server and made sure everything works first. I will do it this way in the future as well.

After a PAINFUL experience because a courier directive changed…
LDAP_SERVER changed to LDAP_URL
This is a great URL for troubleshooting http://www.courier-mta.org/authlib/README.authdebug.html

# cd /xen
# mkdir gopher
# cd gopher/
# tar xjvf ../debian-4.0-20070801.tar.bz2
debian-4.0.img
debian-4.0.xen3.cfg
debian.swap

The sizes were 500M, 20M and 200M and they rounded up by lvcreate.

lvcreate -L512M -n gopher-usr VolGroup00 && \
lvcreate -L32M -n gopher-home VolGroup00 && \
lvcreate -L224M -n gopher-tmp VolGroup00 && \
lvcreate -L5G -n gopher-var VolGroup00
mkfs -t ext3 /dev/VolGroup00/gopher-usr
mkfs -t ext3 /dev/VolGroup00/gopher-var
mkfs -t ext3 /dev/VolGroup00/gopher-tmp
mkfs -t ext3 /dev/VolGroup00/gopher-home

Make the last 3 bytes of the MAC:

dd if=/dev/urandom bs=1 count=3 2>/dev/null | od -tx1 | head -1 | cut -d' ' -f2- | tr -d ' ' | tr '[a-f]' '[A-F]'

/vserver/gopher/gopher.cfg

kernel = "/boot/vmlinuz-2.6-xenU"
memory = 384
name = "gopher"
vif = [ 'bridge=xenbr0,mac=00:16:3e:CF:AA:21' ]
dhcp = "dhcp"
disk = ['file:/xen/gopher/debian-4.0.img,sda1,w'
, 'file:/xen/gopher/debian.swap,sda2,w'
, 'phy:VolGroup00/gopher-usr,sda5,w'
, 'phy:VolGroup00/gopher-home,sda6,w'
, 'phy:VolGroup00/gopher-tmp,sda7,w'
, 'phy:VolGroup00/gopher-var,sda8,w'
]
root = "/dev/sda1 ro"
ramdisk = "/boot/initrd-2.6-xenU.img"

---

I linked the config and restarted the server to test.

ln -s /xen/gopher/gopher.cfg /etc/xen/auto/gopher.cfg

xm create -c gopher.cfg
192.168.0.218
ssh’d to the VM, default password of “password”

Created flip script. vm flip filesystems

~/flip sda5 usr
mount /dev/sda6 /home
# ~/flip sda6 home
# home is empty so it just gives an error. just umount and then mount it to /home
# maybe I will fix this... or not.
~/flip sda7 tmp
~/flip sda8 var

Set the IP variable, imported /etc.

export IP='192.168.0.1'
mkdir ~/etc
cp /etc/mtab ~/etc/ && \
cp /etc/init.d/makedev ~/etc/init.d/ && \
rsync -e ssh -avz root@$IP:/etc/* /etc/ && \
cp -R ~/etc/* /etc/

Change hd? to sd?. Used nano and remarked out cd and floppy. Made note of swap, sda9.
I started a ~/etc/ so that if we need to resync etc we just copy it back to /etc.

mv /etc/fstab{,~} && sed 's#/hd#/sd#' /etc/fstab~ >/etc/fstab
nano /etc/fstab && cp /etc/fstab ~/etc/

I changed the IP to a temp address during the initial reboot. This can cause a little trouble, but less than having 2 machines with the same IP.

nano /etc/network/interfaces && cp /etc/network/interfaces ~/etc/network/

grep -i documentroot /etc/apache-ssl/httpd.conf
DocumentRoot /var/www/ssl

mkdir -p /var/spool
rsync -e ssh -avz root@$IP:/var/spool/* /var/spool/
mkdir -p /var/www
rsync -e ssh -avz root@$IP:/var/www/* /var/www/
mkdir -p /var/mail
rsync -e ssh -avz root@$IP:/var/mail/* /var/mail/

---

Fixed in the model, this is no longer needed.

---

As you may remember, I had to create a script to create /dev/urandom and start ssh. Debian 4.0 added rc.local and broke the link I made before.
There is an exit 0 that is required, but it needs to be at the bottom of the file. I started nano to remove exit 0 from the middle of the file and put it at the end.

cat /etc/init.d/local >>/etc/rc.local && nano /etc/rc.local

---

---

Next we are getting the package list from the running server and applying it to this one. In general, take the defaults to NOT change settings.

ssh $IP 'dpkg --get-selections' >~/selections.dpkg && \
dpkg --set-selections  < ~/selections.dpkg && \
apt-get update && \
apt-get dselect-upgrade

If you get “4gb seg fixup” errors, this will probably fix it.

apt-get install libc6-xen
echo "hwcap 0 nosegneg" > /etc/ld.so.conf.d/nosegneg.conf
ldconfig -v -p 2>&1 | grep libc.so
ldconfig

I stopped postfix and ran this until there was nothing left to update.

rsync -e ssh -avz --delete root@$IP:/var/mail/* /var/mail/

restarted

restarting: shutdown -r now