Nethence NSBH Laboratory Webmail Your IP BBDock
New Software Burns in Hell print | donate | html/css | terms of use
Home | Unix | Windows | Oracle | Obsolete | Hardware | Mechanics | Scripts | Configs | Private

RHEL/XEN paravirtualized guest
 
 
centos5x64 skeleton
Build a guest skeleton,
mkdir -p /data/guests/centos5x64/
cd /data/guests/centos5x64/
wget ftp://ftp.free.fr/mirrors/ftp.centos.org/5.7/os/x86_64/images/xen/vmlinuz
wget ftp://ftp.free.fr/mirrors/ftp.centos.org/5.7/os/x86_64/images/xen/initrd.img
dd if=/dev/zero of=centos5x64.disk bs=1024k count=1 seek=10000
dd if=/dev/zero of=centos5x64.disk2 bs=1024k count=1 seek=30000
cat > centos5x64 <<EOF9
name = "centos5x64"
memory = "1024"
kernel = "vmlinuz"
ramdisk = "initrd.img"
#bootloader = "/usr/bin/pygrub"
disk = ['file:/data/guests/centos5x64/centos5x64.disk,xvda,w',
'file:/data/guests/centos5x64/centos5x64.disk2,xvdb,w']
vif = [ 'vifname=vcentos5x64.0' ]
vcpus = "2"
EOF9
 
 
centos4x64 skeleton
Build a guest skeleton,
mkdir -p /data/guests/centos4x64/
cd /data/guests/centos4x64/
wget ftp://ftp.free.fr/mirrors/ftp.centos.org/4.8/os/x86_64/images/xen/vmlinuz
wget ftp://ftp.free.fr/mirrors/ftp.centos.org/4.8/os/x86_64/images/xen/initrd.img
dd if=/dev/zero of=centos4x64.disk bs=1024k count=1 seek=10000
dd if=/dev/zero of=centos4x64.disk2 bs=1024k count=1 seek=30000
cat > centos4x64 <<EOF9
name = "centos4x64"
memory = "1024"
kernel = "vmlinuz"
ramdisk = "initrd.img"
disk = ['file:/data/guests/centos4x64/centos4x64.disk,xvda,w',
'file:/data/guests/centos4x64/centos4x64.disk2,xvdb,w']
vif = [ 'vifname=vcentos4x64.0' ]
vcpus = "2"
EOF9
 
 
Notes
Note. quotes are mandatory or you might get e.g.,
Error: name <guestname> is not defined
Note. you might want to force a bridge,
vifname=...,bridge=eth0
Note. you might want to force a mac address,
vifname,...,mac=00:16:3e:xx:xx:xx
 
 
Installation methods
ISO image
To use the iso as installation media,
#'file:/data/share/CentOS-5.7-x86_64-bin-1of8.iso,ioemu:hdc:cdrom,r']
Note. centos4 doesn't find the ioemu:hdc cdrom
 
Hard drive
Copy the repository or first cdrom image's content to guest's second disk. Use ext3, mounting ext4 on a loop device isn't working on a centos5 dom0 (mount: Operation not supported).
mkfs.ext3 -F centos4x32.disk2
mkdir loop/
mount -o loop centos4x32.disk2 loop/
cp -R path/to/centos4/* loop/
umount loop/
 
Network
Note. to use kickstart (change NFS_SERVER accordingly),
#extra = "ip=dhcp noipv6 ks=nfs:NFS_SERVER:/data/share/centos5x64.core.ks text"
 
Dummy network
If you can't access the outside world for some reason, use a dummy bridge. On the dom0,
brctl addbr dummybr0
ifconfig dummybr0 10.1.1.1 netmask 255.255.255.0 up
and use that vif for the guest,
vif = [ 'vifname=vcentos4x64.0,bridge=dummybr0' ]
 
 
Installation settings
Launch the guest to start the installation process,
cd /data/guests/centos5x64/
xm cr centos5x64 -c
#xm cr centos4x64 -c
 
During installation, if you choose FTP installation, e.g.,
site: ftp.free.fr
folder: /mirrors/ftp.centos.org/5.7/os/x86_64
#folder: /mirrors/ftp.centos.org/4.8/os/x86_64
press OK or F12.
 
Note. the kernel argument for pygrub (by default),
console=xvc0
 
When prompted for reboot, simply shutdown the guest from the dom0,
xm shu centos5x64
#xm shu centos4x64
otherwise you'll have to 'xm destroy' it when it prompts for a new install... You can now comment out the kernel and installer ramdisk,
#kernel= "vmlinuz"
#ramdisk = "initrd.img"
add pygrub instead,
bootloader = "/usr/bin/pygrub"
Note. it's preferable to use pygrub to make sure "/lib" is in sync with the kernel inside the guest. It's also preferable to make a clean cut separation between dom0 and guests : to enter into guest's single user mode, you do as usual using grub (start the guest with xm create -c do you get there in time before the timeout).
 
 
Post-installation
Disable the hardware clock,
cd /sbin/
ls -l hwclock*
mv hwclock hwclock.dist
touch hwclock
chmod +x hwclock
Note. otherwise we could get that error,
Cannot access the Hardware Clock via any known method.
Use the --debug option to see the details of our search for an access method.
 
Disable intel microcode (rhel4),
chkconfig --list microcode_ctl
chkconfig microcode_ctl off
 
GPM is useless on (xen) serial console,
service gpm stop
chkconfig --list gpm
chkconfig gpm off
 
Disable smartd (rhel4, 5),
chkconfig --list smartd
chkconfig smartd off
 
Disable tcp offloading on rhel5,
ethtool -k eth0 2>/dev/null| grep on$
ethtool -K eth0 tx off
ethtool -K eth0 sg off
ethtool -K eth0 tso off
#ethtool -K eth0 gso off
#ethtool -K eth0 gro off
cat >> /etc/rc.local <<EOF9

echo disabling tcp offloading.
ethtool -K eth0 tx off
ethtool -K eth0 sg off
ethtool -K eth0 tso off
EOF9
 
Disable tcp offloading on rhel4,
ethtool -k eth0 2>/dev/null| grep on$
ethtool -K eth0 tx off
ethtool -K eth0 sg off
cat >> /etc/rc.local <<EOF9

echo disabling tcp offloading.
ethtool -K eth0 tx off
ethtool -K eth0 sg off
EOF9
 
Remove the freaking mac address from the network configuration,
cd /etc/sysconfig/network-scripts/
vi ifcfg-eth0
remove HWADDR=...
cd /etc/sysconfig/
find . | grep .bak$ | xargs rm -f
note. makes it easyer to change cards
apply,
service network restart
 

Last update: Dec 23, 2011
Copyright © 2007-2014 Pierre-Philipp Braun