Introduction ~
What is Virtualization? ~ virtualization is technique of running multiple operating system (OS) on same physical hardware at same time.
There are three types of Virtualization technologies
1) Full virtualization –
a) Hardware emulation – KQEMU
b) Binary translation – VirtualBox
c) Classic virtualization – OpenVZ
2) Para-virtualization
3) OS-level virtualization – Linux-VServer and OpenVZ
** Xen is an open-source para-virtualizing virtual machine monitor (VMM), or “hypervisor”,for a variety of processor. Xen can securely execute multiple virtual machines on a single physical system with near native performance.
** Xen Prerequisites –
1) iproute2 package
2) Linux bridge-utils (/sbin/brctl)
3) Linux hotplug system (/sbin/hotplug and related scripts)
Step 1) How to install Xen on Centos ~
[root@arun ~]# yum install xen.i386 xen-devel.i386 xen-libs.i386 libvirt.i386 libvirt-devel.i386 libvirt-python.i386 virt-manager.i386 virt-clone.i386
Step 2) How to install Xen Kernel for Centos ~
[root@arun ~]# yum install kernel-xen.i686 kernel-xen-devel.i686
* Once installation is completed; Please check the CentOS boot loader configuration file ie “/boot/grub/grub.conf”… and make sure that the first boot entry should look like this…
title CentOS (2.6.18-164.15.1.el5xen)
root (hd0,4)
kernel /boot/xen.gz-2.6.18-164.15.1.el5
module /boot/vmlinuz-2.6.18-164.15.1.el5xen ro root=LABEL=/ rhgb quiet
module /boot/initrd-2.6.18-164.15.1.el5xen.img
Step 3) Reboot the system so that system will boot with Xen Kernel….
That’s it Xen infrastructure is installed on CentOS.
[[root@arun ~]# rpm -qa | egrep “xen|virt” | sort
kernel-xen-2.6.18-164.15.1.el5
kernel-xen-devel-2.6.18-164.15.1.el5
libvirt-0.6.3-20.1.el5_4
libvirt-devel-0.6.3-20.1.el5_4
libvirt-python-0.6.3-20.1.el5_4
python-virtinst-0.400.3-5.el5
virt-manager-0.6.1-8.el5
xen-3.0.3-94.el5_4.3
xen-devel-3.0.3-94.el5_4.3
xen-libs-3.0.3-94.el5_4.3
[[root@arun ~]#
Step 4 ) Test Xen setup – make sure that “libvirtd” service is running
Step 5) Install first Guest CentOS –
* Create Disk as file as shown below….
[[root@arun ~]# dd if=/dev/zero of=/var/xen-disk/centOS.hdd bs=4k seek=2048k count=0
0+0 records in
0+0 records out
0 bytes (0 B) copied, 0.000191 seconds, 0.0 kB/s
[[root@arun ~]# mke2fs -j /var/xen-disk/centOS.hdd
mke2fs 1.39 (29-May-2006)
/var/xen-disk/centOS.hdd is not a block special device.
Proceed anyway? (y,n) y
Filesystem label=
OS type: Linux
Block size=4096 (log=2)
Fragment size=4096 (log=2)
1048576 inodes, 2097152 blocks
104857 blocks (5.00%) reserved for the super user
First data block=0
Maximum filesystem blocks=2147483648
64 block groups
32768 blocks per group, 32768 fragments per group
16384 inodes per group
Superblock backups stored on blocks:
32768, 98304, 163840, 229376, 294912, 819200, 884736, 1605632
Writing inode tables: done
Creating journal (32768 blocks): done
Writing superblocks and filesystem accounting information: done
This filesystem will be automatically checked every 30 mounts or
180 days, whichever comes first. Use tune2fs -c or -i to override.
[[root@arun ~]# mount -o loop /var/xen-disk/centOS.hdd /mnt/
[[root@arun ~]# df -h
Filesystem Size Used Avail Use% Mounted on
/dev/sda5 55G 12G 41G 22% /
tmpfs 829M 12K 829M 1% /dev/shm
/dev/sda2 23G 15G 7.8G 65% /mydata
none 829M 104K 829M 1% /var/lib/xenstored
/var/xen-disk/centOS.hdd
7.9G 147M 7.4G 2% /mnt
[[root@arun ~]#
* We are going to install guestOS from CD/DVD image so we will export this image via FTP so let us
configure ftp server….
* We have copied Centos CD/DVD in “/home/CentOS5.0/” location….
[root@arun ~]# ls /home/CentOS5.0/
CentOS RELEASE-NOTES-cz.html RELEASE-NOTES-fr RELEASE-NOTES-nl.html repodata
EULA RELEASE-NOTES-de RELEASE-NOTES-fr.html RELEASE-NOTES-pt RPM-GPG-KEY-beta
GPL RELEASE-NOTES-de.html RELEASE-NOTES-it RELEASE-NOTES-pt_BR RPM-GPG-KEY-CentOS-5
images RELEASE-NOTES-en RELEASE-NOTES-it.html RELEASE-NOTES-pt_BR.html TRANS.TBL
isolinux RELEASE-NOTES-en.html RELEASE-NOTES-ja RELEASE-NOTES-pt.html
NOTES RELEASE-NOTES-es RELEASE-NOTES-ja.html RELEASE-NOTES-ru
RELEASE-NOTES-cz RELEASE-NOTES-es.html RELEASE-NOTES-nl RELEASE-NOTES-ru.html
[root@arun ~]#
* I have changed anonymous FTP home from default one to “/home/CentOS5.0/” Please details below….
[root@arun ~]# grep ftp /etc/passwd
ftp:x:14:50:FTP User:/var/ftp:/sbin/nologin
[root@arun ~]# vi /etc/passwd
[root@arun ~]# grep ftp /etc/passwd
ftp:x:14:50:FTP User:/home/CentOS5.0:/sbin/nologin
[root@arun ~]#
* Now, restart FTP server and try to access to ftp with IPaddress assigned to bridge “virbr0”. In my case it is “ftp://192.168.122.1”
* Start installation now using “virt-install”
[root@arun ~]# virt-install –name arunOS –os-type=linux –ram=300 –file /var/xen-disk/centOS.hdd –location ftp://192.168.122.1 –nographics –bridge=virbr0
Starting install…
* Welcome to CentOS
+————–+ Manual TCP/IP Configuration +—————+
| |
| Enter the IPv4 and/or the IPv6 address and prefix |
| (address / prefix). For IPv4, the dotted-quad netmask |
| or the CIDR-style prefix are acceptable. The gateway and |
| name server fields must be valid IPv4 or IPv6 addresses. |
| |
| IPv4 address: 192.168.122.2___ / 255.255.255.0___ |
| Gateway: 192.168.0.1______________________________ |
| Name Server: _________________________________________ |
| |
| +—-+ +——+ |
| | OK | | Back | |
| +—-+ +——+ |
| |
| |
+————————————————————+
<Tab>/<Alt-Tab> between elements | <Space> selects | <F12> next screen
* Welcome to CentOS
+—————————–+ Warning +——————————+
| |
| /dev/xvda currently has a loop partition layout. To use this disk |
| for the installation of CentOS, it must be re-initialized, causing |
| the loss of ALL DATA on this drive. |
| |
| Would you like to format this drive? |
| |
| +————–+ +————–+ |
| | Ignore drive | | Format drive | |
| +————–+ +————–+ |
| |
| |
+———————————————————————-+
<Tab>/<Alt-Tab> between elements | <Space> selects | <F12> next screen
* Welcome to CentOS
+————————-+ Partitioning Type +————————-+
| |
| Installation requires partitioning of your hard drive. The |
| default layout is reasonable for most users. You can either |
| choose to use this or create your own. |
| |
| Remove all partitions on selected drives and create default layout. |
| Remove linux partitions on selected drives and create default layout. |
| Use free space on selected drives and create default layout. |
| Create custom layout. |
| |
| Which drive(s) do you want to use for this installation? |
| [*] xvda ^ |
| # |
| |
| +—-+ +——+ |
| | OK | | Back | |
| +—-+ +——+ |
| |
| |
+———————————————————————–+
<Space>,<+>,<-> selection | <F2> Add drive | <F12> next screen
* Welcome to CentOS
+—————————-+ Partitioning +—————————-+
| |
| Device Start End Size Type Mount Point |
| /dev/xvda ^ |
| Free space 1 1045 8192M Free space # |
| : |
| : |
| : |
| : |
| : |
| : |
| : |
| v |
| |
| +—–+ +——+ +——–+ +——+ +—-+ +——+ |
| | New | | Edit | | Delete | | RAID | | OK | | Back | |
| +—–+ +——+ +——–+ +——+ +—-+ +——+ |
| |
| |
+————————————————————————+
F1-Help F2-New F3-Edit F4-Delete F5-Reset F12-OK
* Welcome to CentOS
+—————————-+ Partitioning +—————————-+
| |
| Device Start End Size Type Mount Point |
| /dev/xvda ^ |
| xvda1 1 829 6502M ext3 / # |
| xvda2 830 893 502M swap : |
| Free space 894 1044 1184M Free space : |
| : |
| : |
| : |
| : |
| : |
| v |
| |
| +—–+ +——+ +——–+ +——+ +—-+ +——+ |
| | New | | Edit | | Delete | | RAID | | OK | | Back | |
| +—–+ +——+ +——–+ +——+ +—-+ +——+ |
| |
| |
+————————————————————————+
F1-Help F2-New F3-Edit F4-Delete F5-Reset F12-OK
* Same way configure TZ,root password,packages,boot loader options etc…
* Welcome to CentOS
+———————+ Formatting +———————-+
| |
| Formatting / file system… |
| |
| 70% |
| |
+———————————————————+
<Tab>/<Alt-Tab> between elements | <Space> selects | <F12> next screen
That’s it!
Thank you,
Arun Bagul
