See also OpenXenManager

http://www.citrix.com/xenserver

http://www.xen.org/products/cloudxen.html

• XenServer is a bare-metal (type 1) hypervisor, available for free
• XCP is an Open Source version of Citrix XenServer
• Citrix XenCenter can manage both
• XenCenter requires Windows to run

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.

This page has lots of info clearly explained:

http://www.shermann.name/2011/07/quick-tip-for-installing-ubuntu-as.html

Remote Access is a weak spot in XenServer since the primary management tool is XenCenter on Windows. XenCenter is not NAT-friendly.

Most XenCenter-to-XenServer communications happen on ports 22 (SSH) and 443 (HTTPS). Linux guest consoles use VNC starting on port 5901.

Since standard SSH is available, the first management tool to grab is 'xsconsole', the built-in text-mode console.

As for XenCenter, you can get partial functionality by simply forwarding port 443.

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>

xe sr-list

xe pbd-list sr-uuid=your-SR-uuid

xe pbd-unplug uuid=your-PBD-uuid

xe pbd-destroy uuid=your-PBD-uuid

xe sr-forget uuid=your-SR-uuid

http://www.schirmacher.de/display/INFO/How+to+add+additional+disks+to+XenServer+host

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/

It is advisable to partition the new disk with one large partition as opposed to using the bare drive for LVM because many tools will report an unpartitioned drive as 'empty'.

Verify the new local disk is visible to the XenServer host OS and create a single large partition of type 8e (Linux LVM). Use gdisk to create a GPT partition table for disks over 2TB.

gdisk /dev/sdx                #where x is your new drive

cat /proc/partitions

ll /dev/disk/by-id

Survey the existing storage repositories:

xe sr-list

xe sr-create content-type=user type=lvm device-config:device=/dev/disk/by-id/scsi-SATA_ST31000528AS_9VP1JTGC-part1 shared=false name-label="Local storage 2"

• One benefit of extending a volume to a second drive is that you will have a single large volume to work with. If you need this, it's worth it.
• One down-side is that your volume now depends on two drives and is therefore twice as likely to fail.

After partitioning the drive (x) as per above:

vgdisplay

vgextend VG_XenStorage-xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx /dev/sdx1

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

http://kb.softescu.ro/server-administration/linux-server-administration/how-to-create-a-local-iso-storage-repository-on-citrix-xenserver/

This will only create a small SR to hold smallish (rescue?) images.

DO NOT FILL the Dom0 partition too full!

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

To create an ISO image from a physical CD/DVD:

• Create the ISO storage repository as above
• Place the optical disc in the XenServer's optical drive
• Use dd to create the image and place it in the SR

dd if=/dev/dvd of=/var/opt/xen/iso_library/Windows_Server_2008_R2_OEM.iso

http://www.schirmacher.de/display/INFO/How+to+reattach+a+disk+to+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/

http://burm.net/2012/01/28/xenserver-tips-and-tricks-auto-start-your-vm/

• As of XenServer 6, you can't configure a VM to auto-start in the GUI
• vApp has been introduced
• vApp gives control over the order and delays of a group of VMs

In a simple setup, you can configure VMs to auto-start from the CLI:

xe pool-list
xe pool-param-set uuid=UUID other-config:auto_poweron=true
xe vm-list
xe vm-param-set uuid=UUID other-config:auto_poweron=true

xe vm-list

xe appliance-create name-label=<name-label> [name-description=<name-description>]

xe appliance-list

xe vm-param-set uuid=<VM-UUID> appliance=<appliance-uuid> order=0 start-delay=45
xe vm-param-set uuid=<VM-UUID> appliance=<appliance-uuid> order=1 start-delay=45

appliance-destroy uuid=<appliance-uuid>

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

• vApp feature introduced in XenServer 6
• vApp feature keyed to HA
• Not currently configurable via the GUI
• vApps won't auto-start on a cold boot

xe appliance-list

Append these lines to /etc/rc.local:

sleep 20
/opt/xensource/bin/xe appliance-start uuid=[uuid-vapp]

Don't bother installing the Tools on a Linux guest if you don't have a Xen kernel.

uname -a

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

mount /dev/xvdd /mnt

/mnt/Linux/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

mount /dev/xvdd /mnt

mv /etc/redhat-release /etc/redhat-release-sme
echo "CentOS release 5 (Final)" > /etc/redhat-release

/mnt/Linux/install.sh

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

ln -s /etc/rc.d/init.d/xe-linux-distribution /etc/rc7.d/S26xe-linux-distribution

http://blog.vhowto.info/2010/10/17/xenserver-5-6-network-configuration-part-3/

Design Guide: http://support.citrix.com/servlet/KbServlet/download/27046-102-666250/XS-design-network_advanced.pdf

Move a XenServer Pool to a Different IP Subnet: http://support.citrix.com/article/CTX123477

• Define a gateway only on the Mangement interface
• You can't use a VLAN for the Management interface
  • Unless it's the 'default' or 'native' VLAN
  • Or handled by your switch
  • Best practice is no VLAN on Management interface

http://www.fatmin.com/2011/11/how-to-create-a-dedicated-storage-nic-in-xenserver.html

http://www.fatmin.com/2012/07/xenserver-how-to-build-and-configure-a-dedicated-nfs-storage-bond.html

Use tab-completion for xe commands.

First we need to get the uuid of the PIF (physical interface) that we want to use:

xe pif-list host-name-label=<your_hostname>

Next we reconfigure our PIF:

xe pif-reconfigure-ip mode=static IP=<your-ip-on-nfs-vlan> netmask=<your-mask> uuid=<pif-uuid>
xe pif-param-set disallow-unplug=true uuid=<pif-uuid>
xe pif-param-set other-config:ManagementPurpose="Storage" uuid=<pif-uuid>

We may want to enable Jumbo Frames:

xe vif-list
xe-switch-network-backend openvswitch
xe vif-param-set uuid=<vif_uuid> other-config:mtu=9000

Alternatively you can use xe pif-forget to remove the interface from the Xencenter database and configure it manually via the XenServer CLI like you would any other interface in Linux, however this could be more confusing in the long run.

xe vm-disk-list vm=<name_of_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.

http://support.citrix.com/article/CTX121875

http://linuxnet.ch/groups/linuxnet/wiki/51a8b/XenServer_HowTo_Convert_HVM_to_PV_RHELSuSE.html

http://djlab.com/2010/10/convert-xenserver-hvm-to-pv-paravirtual/

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

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.

http://www.gossamer-threads.com/lists/xen/api/266896

http://dsstos.blogspot.com/2008/01/nfs-and-oracle-mount-options-noac.html

In an NFS VHD storage repository, VM images are stored as thin-provisioned VHD format files on a shared NFS target.

XenServer requires NFS Version 3 over TCP for remote storage use.