Installation and management of XEN on Redhat-linux
$ yum install xen kernel-xen*
Reboot with xen kernel after changes in grub
$ ps aux | grep xend
If you do not see xend in the resulting listing, you need to start it yourself by switching to root with su – and then running
$ /etc/init.d/xend start
$ free -m total used free shared buffers cached Mem: 942 332 609 0 26 239 -/+ buffers/cache: 66 875 Swap: 1996 0 1996
$ xm list
which prints out a list of all the virtual machines that are running and how much RAM they have allocated — you should see Domain-0, which is your current system, in the list.
$ xm list Name ID Mem(MiB) VCPUs State Time(s) Domain-0 0 942 1 r----- 55.4
The output from xm list probably shows that domain 0 is taking up all the RAM on your system, which means there is no room to create a new guest OS.
$ xm mem-set Domain-0 256 $ xm mem-max Domain-0 256
Run the command xm mem-set Domain-0 256 to have domain 0 use 256MB RAM
$ xm list Name ID Mem(MiB) VCPUs State Time(s) Domain-0 0 256 1 r----- 58.2
****Note that for the default setup, networking for guest OS's is bridged. This means that they will get an IP address on the same network as your host, thus, if you have a DHCP server providing addresses, you will need to ensure that it is configured to give addresses to your guests. You can change to another networking type by editing /etc/xen/xend-config.sxp
$ virt-install What is the name of your virtual machine? test How much RAM should be allocated (in megabytes)? 256 What would you like to use as the disk (file path)? /opt/test1 How large would you like the disk (/opt/test1) to be (in gigabytes)? 4 Would you like to enable graphics support? (yes or no) no What is the install location? /opt/testinst ERROR: Install media location must be an NFS, HTTP or FTP network install source, or an existing local file/device What is the install location? http://192.168.50.50/centos52
This information can also be passed as command line options; run with an argument of –help for more details. In particular, kickstart options can be passed with
virt-install -x ks=options eg virt-install -x ks=http://192.168.50.8/rhelas.cfg
$ /usr/sbin/virt-install The following questions about the new guest OS will be presented. This information can also be passed as command line options; run with an argument of --help for more details. In particular, kickstart options can be passed with -x ks=options. 1. What is the name of your virtual machine? This is the label that will identify the guest OS. This label will be used for various xm commands and also appear in virt-manager the Gnome-panel Xen applet. In addition, it will be the name of the /etc/xen/<name> file that stores the guest's configuration information. 2. How much RAM should be allocated (in megabytes)? This is the amount of RAM to be allocated for the guest instance in megabytes (eg, 256). Note that installation with less than 256 megabytes is not recommended. 3. What would you like to use as the disk (path)? The local path and file name of the file to serve as the disk image for the guest (eg, /home/joe/xenbox1). This will be exported as a full disk to your guest. 4. How large would you like the disk to be (in gigabytes)? The size of the virtual disk for the guest (only appears if the file specified above does not already exist). 4.0 gigabytes is a reasonable size for a "default" install 5. Would you like to enable graphics support (yes or no): Should the graphical installer be used? 6. What is the install location? This is the path to a Fedora Core 6 installation tree in the format used by anaconda. NFS, FTP, and HTTP locations are all supported. Examples include: * nfs:my.nfs.server.com:/path/to/test2/tree/ * http://my.http.server.com/path/to/tree/ * ftp://my.ftp.server.com/path/to/tree {i} Installation must be a network type. It is not possible to install from a local disk or CDROM. It is possible, however, to set up an installation tree on the host OS and then export it as an NFS share.
The xen config files are usually found under /etc/xen
to restart a console with a mc
$ xm create -c <configfile>
You can connect to the console of any virtual machine by running
$ xm list $ xm console <yourvmname>
Xen request the VM to shutdown
$ xm shutdown <yourvmname>
On Linux, this goes through the whole shutdown sequence properly, ensuring that the machine is cleanly terminated. If you want an immediate shutdown, use
$ xm destroy yourvm
but make sure the virtual machine is in a safe state first — if you have a text file open and unsaved, for example, it will be lost.
The xm command can also be used to save snapshots of a virtual machine, rather than just switching them off. To do this, use
$ xm save yourvm yourvm.state
That command essentially saves the RAM of the yourvm VM (change yourvm to whatever you called your virtual machine) to a file and then turns off the VM. To restore a saved state, just use
$ xm restore yourvm.state
To display top-like statistics for all running machines:
$ /usr/sbin/xm top
On the virtualization host server, open a terminal and enter
xm delete vm_name
to delete the virtual machine’s reference in xenstore so it is no longer managed.
Hacks
For CDROM
open the xen config under /ect/xen/mc-name and add
eg if the xm machine is called relay1 under /ect/xen/relay1 add disk = [ "tap:aio:/opt/relay1,xvda,w", 'phy:/dev/cdrom,hdc:cdrom,r'] After starting the mc try mount /dev/hdc /media/
To mount a iso in place of cdrom
disk = [ "tap:aio:/com_xen/atoq,xvda,w",'file:/tmp/fedorax.iso,hdc:cdrom,r' ] After starting the mc try mount /dev/hdc /media/ Or in rc.local add ln -s /dev/hdc /dev/cdrom to be able to mount /dev/cdrom
To automatically run the guest after a system (Dom0) reboot, we have to create the following link:
$ ln -s /etc/xen/[guest_name] /etc/xen/auto/
For 2 network-interfaces
Shut down the xen m/c first
in /etc/xen/xend-config.sxp find (network-script network-bridge) line replace with (network-script network-multi-bridge)
$ cd /etc/xen/scripts
$ vi network-multi-bridge #!/bin/sh dir=$(dirname "$0") "$dir/network-bridge" "$@" vifnum=0 bridge=xenbr0 netdev=eth0 "$dir/network-bridge" "$@" vifnum=1 bridge=xenbr1 netdev=eth0 (or eth1)
Be sure to make the script executable
$ chmod +x network-multi-bridge
In my /etc/xen/test config I’v added a second interface
name = "test" uuid = "44147e5d-a9a1-dfa5-24a5-646b9543ccbb" maxmem = 256 memory = 256 vcpus = 1 bootloader = "/usr/bin/pygrub" on_poweroff = "destroy" on_reboot = "restart" on_crash = "restart" vfb = [ ] disk = [ "tap:aio:/opt/test1,xvda,w" ] vif = [ "mac=00:16:3e:1e:83:6e,bridge=xenbr0", "mac=00:16:3e:1e:83:7e,bridge=xenbr1" ]
Please restart
xend
service
To generate a unique mac address for use
echo "#! /usr/bin/python # macgen.py script generates a MAC address for Xen guests # import random mac = [ 0x00, 0x16, 0x3e, random.randint(0x00, 0x7f), random.randint(0x00, 0xff), random.randint(0x00, 0xff) ] print ':'.join(map(lambda x: '%02x' % x, mac))" > /tmp/macgen $ python /tmp/macgen
The configuration files in /etc/xen are in text format and so are easily edited.
For example, if you want to change the number of CPUs a VM sees, look for the vcpus setting.
Note that these are virtual CPUs rather than real ones —
you can set this to 8 and have your guest see eight CPUs, even if your actual machine has just one
Sorry, the comment form is closed at this time.
-
Recent
- Set Time Zone + Fedora 18
- Fedora 17 + Tata Photon (Huawei)
- Fedora 17: Install OpenSSH Server
- Change the default keyring password
- Error: Could not stat() command file ‘/usr/local/nagios/var/rw/nagios.cmd’!
- Gnone 3.X adding personal launcher
- Gnome 3.x Change Panel
- KDE remove autostart programs
- GPS on Linux
- Debian Squeeze change root password
- Download YouTube Videos on Linux
- Pidgin + The certificate for omega.contacts.msn.com could not be validated
-
Links
-
Archives
- April 2013 (1)
- September 2012 (2)
- August 2012 (2)
- July 2012 (2)
- November 2011 (1)
- July 2011 (1)
- April 2011 (1)
- January 2011 (1)
- November 2010 (1)
- September 2010 (2)
- July 2010 (3)
- March 2010 (1)
-
Categories
-
RSS
Entries RSS
Comments RSS