http://www.citrix.com/xenserver

XenServer is a bare-metal hypervisor, available for free, that is similar to VMware ESXi.

Requires Windows to run the XenCenter management tool.

Quick Installation Guide:

http://www.citrix.com/site/resources/dynamic/salesdocs/XenServer_Quick_Installation_Guide.pdf

Other documentation:

http://www.citrix.com/xenserver_additionalresources_free

• Version upgrades are done with the Rolling Pool Upgrade tool within XenCenter
• Command line updates are more reliable and faster

http://updates.xensource.com/XenServer/6.0.0/XenCenter?pool_6.0.0=1

wget http://support.citrix.com/servlet/KbServlet/download/28993-102-680294/XS60E001.zip
wget http://support.citrix.com/servlet/KbServlet/download/29185-102-680311/XS60E002.zip
wget http://support.citrix.com/servlet/KbServlet/download/29609-102-680420/XS60E003.zip
wget http://support.citrix.com/servlet/KbServlet/download/29484-102-680350/XS60E004.zip

for x in XS*.zip; do unzip $x; done

for x in *.xsupdate; do xe patch-upload file-name=$x; done

Then install the updates one at a time, in order, using the UUID's printed by the last command:

xe patch-pool-apply uuid=<uuid-of-update>

Then reboot the XenServer host:

reboot

For a single XenServer, the above commands would suffice when run from the commmand line of the XenServer.

To update multiple XenServers, you would download the updates once, then push them to multiple servers by running additional commands specifying server/user/password on the 'xe patch-upload' and 'xe patch-pool-apply' commands.

Remote Access is a weak spot in XenServer since everything is managed by XenCenter (on Windows) and XenCenter doesn't include any way of getting through firewalls.

The easiest way I've found to access the console of a VM running on a XenServer behind NAT is:

1. Enable remote SSH access directly to the XenServer
   • You can forward a non-standard port at the firewall (22222) to the standard port 22 at the XenServer
2. To access a VM's console, you must tunnel through localhost (the XenServer)
3. Use SSH port forwarding to forward a VM's VNC port (5901, 5902, 5903, etc.) to 'localhost'
   • Each VM runs on a different VNC port
   • Each VM's VNC console is only available to localhost (the XenServer)
4. The IP address of the VM doesn't matter and can even change without affecting remote access

You can determine which VNC port is assigned to which VM like this:

Log into the XenServer via SSH:

ssh -p 22222 -l root <your-remote-xenserver>

Determine the VNC port of your target VM:

xe vm-list
xe vm-list name-label="<target-vm-name>" params=dom-id --minimal
netstat -lp|grep -w <domid> |awk '{print $4}'|cut -d: -f2

Now you can forward the port(s) and access the VNC console of the VM from other terminals on your remote workstation:

ssh -p 22222 -l root -L <local-vnc-port>:localhost:<vm-vnc-port> <your-remote-xenserver>

vncviewer localhost:<last-vnc-port-digit>

OpenXenManager is a graphical interface to manage XenServer / Xen Cloud Platform (XCP) hosts through the network. OpenXenManager is an open-source multiplatform clone of XenCenter (Citrix).

http://sourceforge.net/projects/openxenmanager/

sudo apt-get install subversion python-glade2 python-gtk-vnc
cd ~/bin/
svn co https://openxenmanager.svn.sourceforge.net/svnroot/openxenmanager openxenmanager

Launcher command:

python ~/bin/openxenmanager/window.py

sudo yum -y install gtk-vnc-python subversion
cd ~/bin/
svn co https://openxenmanager.svn.sourceforge.net/svnroot/openxenmanager openxenmanager

Launcher:

python ~/bin/openxenmanager/trunk/window.py

http://www.xendesktopmaster.com/how-to-add-an-additional-local-disk-to-your-xenserver-5-5-host/

http://www.peppercrew.nl/index.php/2012/03/adding-extra-local-storage-space-to-xenserver-6-0/

Verify the new local disks are visible to the XenServer host OS:

cat /proc/partitions

ll /dev/disk/by-id 

Survey the existing storage repositories:

xe sr-list

Create the new SR:

EXT storage repository

CIFS → Centos CIFS ISO library → \\192.168.0.6\nas_vg_1.nas_vol_1.no_backup\Centos

\\server\share\folder

Set username and password.

You can't set folders using NFS, only shares, so .iso files must be in the top-level folder with NFS:

No_Backup NFS ISO library → 192.168.0.6:/mnt/nas_vg_1/nas_vol_1/no_backup

Note that this will probably break and have to be fixed after a version upgrade!

mkdir -p /var/opt/xen/iso_library

xe sr-create name-label ="ISO Repository" type=iso device-config:location=/var/opt/xen/iso_library/ device-config:legacy_mode=true content-type=iso

You may have to give the new SR a name in XenCenter.

I suspect you would need to recreate the directory and recopy the ISO files to repair after upgrading your XenServer.

http://support.citrix.com/article/CTX121896

Start with 5.4 32-bit template and use mostly defaults.

Install from URL:

http://mirrors.easynews.com/linux/centos/5.5/os/i386/

http://mirrors.easynews.com/linux/centos/5.5/os/x86_64/

Do NOT start the VM automatically.

Adjust the Description and Storage Name and Storage Description as needed.

Start the VM - be patient because some large files are transferred over the 'net.

URL:

http://mirrors.easynews.com/linux/debian/

then:

debian.mirrors.easynews.com

apt-get install openssh-server

URL:

http://distro.ibiblio.org/pub/linux/distributions/smeserver/releases/testing/8.0beta6/smeos/i386/

In XenCenter, select xs-tools.iso for the DVD drive.

mount /dev/xvdd /mnt
cd /mnt/Linux

bash install.sh

wget -q http://updates.vmd.citrix.com/XenServer/5.6.0/GPG-KEY -O- | apt-key add -

/etc/init.d/xe-linux-distribution start

mv /etc/redhat-release /etc/redhat-release-sme
echo "CentOS release 5 (Final)" > /etc/redhat-release
/etc/init.d/xe-linux-distribution start
ln -s /etc/rc.d/init.d/xe-linux-distribution /etc/rc7.d/S26xe-linux-distribution

xe vm-disk-list vm= < name of the VM >

xe vm-list

xe vm-param-set HVM-boot-policy="BIOS order" uuid=UUID of VM

Next, on the “General” tab, select the “Edit” button. On the “Startup Options” tab, ensure that “DVD-Drive” is moved to the top.

Before starting VM, make sure that the ISO that you want is in the VM's DVD-Drive located on the “Console” tab.

Proceed to use SUSE CD-ROM (or DVD) to upgrade, or Linux Rescue media, etc. Once all changes have been made to the VM, you will need to revert back the change to the VM's parameter with the following command:

xe vm-param-set HVM-boot-policy=“” uuid=UUID of VM

Reboot VM

Final caveat… mouse is unavailable as it is “HVM mode” and no device has been loaded.

See XenServer Backup.

See ATA over Ethernet (AoE)

http://forums.citrix.com/thread.jspa?threadID=296776

http://support.citrix.com/article/CTX116020

http://forums.citrix.com/message.jspa?messageID=1367138

* Bonded NICs * Separate network paths for * VMs * Storage * Management * 6 NICs per server! * SAN/NAS storage

XenCenter - Port 443

http://66.165.176.77/servlet/KbServlet/download/2389-102-647335/Citrix_TCP_Ports_0167.pdf

iptables -nL -v --line-numbers

iptables -I RH-Firewall-1-INPUT 13 -p udp --dport 123 -j ACCEPT
service iptables save

This sample firewall allows NTP and limits access to ports 22, 80 and 443 by the sourde IP.

/etc/sysconfig/iptables

# Generated by iptables-save v1.3.5 on Mon Apr  9 00:15:34 2012
*filter
:INPUT ACCEPT [0:0]
:FORWARD ACCEPT [0:0]
:OUTPUT ACCEPT [135:25337]
:RH-Firewall-1-INPUT - [0:0]
-A INPUT -j RH-Firewall-1-INPUT 
-A FORWARD -j RH-Firewall-1-INPUT 
-A RH-Firewall-1-INPUT -i lo -j ACCEPT 
-A RH-Firewall-1-INPUT -p icmp -m icmp --icmp-type any -j ACCEPT 
-A RH-Firewall-1-INPUT -p esp -j ACCEPT 
-A RH-Firewall-1-INPUT -p ah -j ACCEPT 
-A RH-Firewall-1-INPUT -d 224.0.0.251 -p udp -m udp --dport 5353 -j ACCEPT 
-A RH-Firewall-1-INPUT -p udp -m udp --dport 631 -j ACCEPT 
-A RH-Firewall-1-INPUT -p tcp -m tcp --dport 631 -j ACCEPT 
-A RH-Firewall-1-INPUT -i xenapi -p udp -m udp --dport 67 -j ACCEPT 
-A RH-Firewall-1-INPUT -m state --state RELATED,ESTABLISHED -j ACCEPT 
-A RH-Firewall-1-INPUT -p udp -m state --state NEW -m udp --dport 694 -j ACCEPT 
-A RH-Firewall-1-INPUT -s 209.104.9.32/255.255.255.240 -p tcp -m state --state NEW -m tcp --dport 22 -j ACCEPT 
-A RH-Firewall-1-INPUT -s 209.193.64.248/255.255.255.248 -p tcp -m state --state NEW -m tcp --dport 22 -j ACCEPT 
-A RH-Firewall-1-INPUT -s 72.200.111.140 -p tcp -m state --state NEW -m tcp --dport 22 -j ACCEPT 
-A RH-Firewall-1-INPUT -s 209.193.64.2 -p tcp -m state --state NEW -m tcp --dport 22 -j ACCEPT 
-A RH-Firewall-1-INPUT -s 209.104.9.32/255.255.255.240 -p tcp -m state --state NEW -m tcp --dport 80 -j ACCEPT 
-A RH-Firewall-1-INPUT -s 209.193.64.248/255.255.255.248 -p tcp -m state --state NEW -m tcp --dport 80 -j ACCEPT 
-A RH-Firewall-1-INPUT -s 72.200.111.140 -p tcp -m state --state NEW -m tcp --dport 80 -j ACCEPT 
-A RH-Firewall-1-INPUT -s 209.193.64.2 -p tcp -m state --state NEW -m tcp --dport 80 -j ACCEPT 
-A RH-Firewall-1-INPUT -p udp -m udp --dport 123 -j ACCEPT 
-A RH-Firewall-1-INPUT -s 209.104.9.32/255.255.255.240 -p tcp -m state --state NEW -m tcp --dport 443 -j ACCEPT 
-A RH-Firewall-1-INPUT -s 209.193.64.248/255.255.255.248 -p tcp -m state --state NEW -m tcp --dport 443 -j ACCEPT 
-A RH-Firewall-1-INPUT -s 72.200.111.140 -p tcp -m state --state NEW -m tcp --dport 443 -j ACCEPT 
-A RH-Firewall-1-INPUT -s 209.193.64.2 -p tcp -m state --state NEW -m tcp --dport 443 -j ACCEPT 
-A RH-Firewall-1-INPUT -j REJECT --reject-with icmp-host-prohibited 
COMMIT
# Completed on Mon Apr  9 00:15:34 2012

http://www.virtues.it/2012/01/howto-autostart-xs-vapp/

• vApp Feature introduced in XenServer 6
• Not currently configurable via the GUI
• By default, vApps won't auto-start on a cold boot

xe appliance-list
xe appliance-list <vm-name>

Add this line to /etc/rc.local:

xe appliance-start uuid=[uuid-vapp]

Assumes:

1. Running LVM in the guest (you can do this without it, but it's difficult). 2. You're using a filesystem such as Ext3 on the partition you wish to expand which supports online expansion. 3. You're able to perform a backup just in case something goes wrong.

Steps:

5-11. Run pvresize /dev/xvdX“ (replacing “X” with the disk identified in step 4). 1. Shut down the virtual machine from XenCenter.

2. Resize the VDI from XenCenter to the appropriate size

3. Start the VM up.

4. Run “fdisk -l” to locate the virtual disk by looking at the size.

5. Run “fdisk /dev/xvdX” (replacing “X” with the disk identified in step 4).

6. Create a new partition (usually primary) using all available space. The default options will be sufficient. To do this, type “n”, follow the instructions to create the partition, then type “p” to verify the changes and then “w” to write and then “q” to quit.

7. Reboot the VM again to allow udev to create the appropriate /dev/ node for the partition just created.

8. Create a new physical volume by running “pvcreate /dev/xvdXY” (replacing “X” with the disk identified in step 4).

9. Locate the Volume Group containing the partition by running “mount”. Look for the partition you wish to resize in the list. You should also see a reference to the Volume Group (e.g. “VolGroup00”) and the Logical Volume (e.g. “LogVol00”) take note of these two items.

10. Extend your Volume Group with the newly added Physical Volume by running vgextend as shown: “vgextend VolGroupXX /dev/xvdXY” (Replace “VolGroupXX” with the Volume Group as identified in step 9, and ”/dev/xvdXY“ as identified in steps 4 and 6).

11. Confirm the Volume Group has free storage by running “vgs”. This should indicate the total size and the amount of storage free for allocation to logical volumes.

12. Expand the Logical Volume using all available free extents by running: lvextend -l+100%FREE /dev/VolGroupXX/LogVolYY Remember to change VolGroupXX and LogVolYY as appropriate.

13. Assuming ext3 or ext2 is being used (other filesystems will have their own tools for this purpose), resize the filesystem by running: resize2fs /dev/VolGroupXX/LogVolYY

14. As a precaution, reboot the system again checking the filesystem for errors: shutdown -r now -F

15. Observe the output of the “fsck” execution during startup and monitor for any errors that may indicate corruption.

When you install Redhat on XenServer it does not by default enable a virtual video device. You are only given the text console by default.

Citrix's Virtual Machine Installation Guide does document how to enable the typical X console using VNC.

Check to make sure that vnc-server and gdm are installed.

rpm -q vnc-server gdm

If they are not, install them.

yum install vnc-server gdm

Modify /etc/gdm/custom.conf so the default server is a VNC server:

[servers]
0=VNC
[server-VNC]
name=VNC Server
command=/usr/bin/Xvnc -SecurityTypes None -geometry 1024x768 -depth 16 -BlacklistTimeout 0
flexible=true

When GDM is running it should be listening on port 5900. Make sure that the iptables firewall allows access to this port from any machine running XenCenter or wanting to connect.

iptables -N vnc
iptables -I INPUT -p tcp -m state --state NEW -m tcp --dport 5900 -j vnc
iptables -A vnc -s 134.114.0.0/255.255.0.0 -p tcp -m state --state NEW -m tcp --dport 5900 -j ACCEPT
iptables -A vnc -p tcp -m tcp -m state --state NEW --dport 5900 -j REJECT

Now everything is set up, but by default Redhat on XenServer starts up into runlevel 3. This does not by default start GDM. So you can modify the default runlevel in /etc/inittab or as I would recommend, simply use telinit 5 to start it and telinit 3 to turn it off. This saves memory and CPU cycles.