Category Archives: XenServer

Auto Start VM after XenServer reboot

Posted on by
Reply

SSH or gain command line access to XenServer

First we need to enable the Pool to allow auto starting
Second we will need to turn on the auto_poweron to true

In the following examples replace the UUIDs with your UUIDs

Find Pool UUID

You can find the pool UUID by running the “xe pool-list” Command. Note: you’ll still have a pool even if there is only a single server.

# xe pool-list
uuid ( RO) : 2e587aeb-de94-hf29-3eda-923d8he634fe

Enable auto_poweron for the pool

xe pool-param-set uuid=2e587aeb-de94-hf29-3eda-923d8he634fe other-config:auto_poweron=true

Verify that it is enabled

xe pool-param-list uuid=2e587aeb-de94-hf29-3eda-923d8he634fe  | grep auto_poweron

List VM UUID’s

Locate the UUID’s of the VM’s you want to start

# xe vm-list
uuid ( RO)           : 521be58a-3495-ea29-02a0-85ffcda06583
     name-label ( RW): CentOS 7
    power-state ( RO): running

Enable auto start

Run the following command for each VM you want to auto start. Change the UUID to the UUID of the vm you want to start.

xe pool-param-set uuid=521be58a-3495-ea29-02a0-85ffcda06583  other-config:auto_poweron=true

Print parameter settings

Use the following command to verify that the auto_poweron option is enabled.

xe vm-param-list uuid=521be58a-3495-ea29-02a0-85ffcda06583 | grep -i poweron | cut -d";" -f1

Example output

                      other-config (MRW): auto_poweron: true

https://support.citrix.com/article/CTX133910

Setup Windows File Share for Citrix XenServer

Posted on by
Reply

Setup Share in windows

You may need to enable the Network Sharing and discovery in the network sharing center before proceeding with the following steps.

Create a new directory, right click and hit properties.

Under Sharing, hit Advanced Sharing…

Enable the Check mark for “Share this folder” and verify the share name is correct. In this example we are sharing a folder called XenServerShare

Setup Share in XenCenter

From XenCenter, hit add new Storage Repository and run through the wizard. When you get to the Share path put in \\share-ip-address\Share\Path

Example: If the IP address of the computer with the Share is 192.168.1.2 and you shared your Downloads folder, the path would be as follows

\\192.168.1.2\Downloads

Use the share computers username and password to log in to it.

XenServer Commands

Posted on by
Reply

List, unplug, or destroy PBD storage repository

xe pbd-list
xe pbd-unplug uuid=[UUID for VM]
xe sr-destroy uuid=[UUID for VM]

List, unplug, or destroy storage repository.

xe sr-list
xe sr-unplug uuid=[UUID for VM]
xe sr-destroy uuid=[UUID for VM]

List VM’s

xe vm-list

Shutdown VM

xe vm-shutdown uuid=[UUID for VM]

Force shutdown VM

xe vm-shutdown -–force uuid=[UUID for VM]

List Task

xe task-list

Cancel Task

xe task-cancel uuid=[task uuid]

External Links

http://www.queryadmin.com/801/useful-storage-repository-commands-xenserver/

https://www.serveroperations.net/citrix/shutdown-a-hung-vm-on-xenserver

https://linuxconfig.org/how-to-take-and-restore-vm-snapshot-using-command-line-on-xenserver

Setup SNMP on XenServer

Posted on by
Reply

log into the Xenserver via SSH, or get a console through XenCenter.

Open up the snmpd.conf file with your favorite text editor, nano, vi etc.

vi /etc/snmp/snmpd.conf

Find the line the following line

com2sec notConfigUser default public

and change the source “default” to the allowed IP ranges and the community “public” to whatever you want your new community string to be.

Example:

com2sec notConfigUser 192.168.1.0/24 privateString

Save, exit and start snmpd

service snmpd start

Add the following line in your iptables config.  It needs to be above the COMMIT line.

-A RH-Firewall-1-INPUT -s 0.0.0.0/0 -m udp -p udp --dport 161 -j ACCEPT

Restart iptables

service iptables restart

You should be good to go.

Increase hard disk size on Windows VM in XenServer

Posted on by
Reply

To increase a Windows VM disk size you’ll first need to shut down the VM and then increase the disk size from XenCenter.  When you boot back up into the VM, the extra space shows up as unallocated.  All that needs to be done is the main partition needs to be extended.

Open up the Windows Disk Management Utility.  You can do this by clicking on the start button, typing in disk management and hit enter.  This will bring up the Disk Management program.

In disk manager, you should see the Unallocated space at the end of Disk 0, i.e. your main drive.  Right click on your main partition (C:) and click Extend Volume.  You will be presented with a wizard that will walk you through extending your disk.

Example:

Before increasing the VM’s disk size.

0

The unallocated space is the extra space that we added via XenCenter.  Right click on the middle partition (C:), and click extend.

1

After were are finished extending the partition, we see that our main partition is about 8GB larger.

3

How to add extra space to Linux VM in XenServer

Posted on by
Reply

Before we start you will need to do the following in XenCenter

  • Shutdown the VM
  • Increase the virtual hard drive size of the Linux VM
  • Boot the VM back up

Before starting any of the following, it is a good idea to backup any data you would not want to lose.  You should not lose any data following these steps, but there is always the possibility for something to go wrong.

What is going to happen

  1. Delete the main partition.  We are going to recreate it.
  2. Create a new partition that starts on the same boundary as the previous partition
  3. Write changes to disk and reboot
  4. Resize the Disk
  5. Check that everything went well

The path to the disk is “/dev/xvda” the LVM path/name is “/dev/VolGroup/lv_root”  The goal is to increase lv_root’s size from about 8GB to about 12GB. If for some reason your drive is not “xvda” or your LVM name is different, change the commands accordingly.

Here are the commands in a nutshell.

fdisk /dev/xvda                        <-- Edit the Partition Table
reboot                                 <-- Reboot to apply the partition table updates
pvdisplay                              <-- Display Physical Volume info
pvresize /dev/xvda2                    <-- Resize Physical Volume
lvresize /dev/xvda2 -l +100%FREE       <-- Resize Logical Volume
resize2fs /dev/VolGroup/lv_root        <-- Resize File System

Example:

You may be able to substitute all the fdisk commands with
`parted /dev/xvda resizepart 2 100%`
Change 2 for the actual partition you need to resize.

All the keys and command that were hit and executed are in bold.

[root@localhost ~]# fdisk /dev/xvda

WARNING: DOS-compatible mode is deprecated. It's strongly recommended to
         switch off the mode (command 'c') and change display units to
         sectors (command 'u').

Command (m for help): p

Disk /dev/xvda: 12.9 GB, 12884901888 bytes
255 heads, 63 sectors/track, 1566 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x00066ace

    Device Boot      Start         End      Blocks   Id  System
/dev/xvda1   *           1          64      512000   83  Linux
Partition 1 does not end on cylinder boundary.
/dev/xvda2              64        1045     7875584   8e  Linux LVM
Command (m for help): d
Partition number (1-4): 2

Command (m for help): p

Disk /dev/xvda: 12.9 GB, 12884901888 bytes
255 heads, 63 sectors/track, 1566 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x00066ace

    Device Boot      Start         End      Blocks   Id  System
/dev/xvda1   *           1          64      512000   83  Linux
Partition 1 does not end on cylinder boundary.

Command (m for help): n
Command action
   e   extended
   p   primary partition (1-4)
p
Partition number (1-4): 2
First cylinder (64-1566, default 64): 
Command (m for help): p

Disk /dev/xvda: 12.9 GB, 12884901888 bytes
255 heads, 63 sectors/track, 1566 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x00066ace

    Device Boot      Start         End      Blocks   Id  System
/dev/xvda1   *           1          64      512000   83  Linux
Partition 1 does not end on cylinder boundary.
/dev/xvda2              64        1566    12065871   83  Linux

Command (m for help): wq
The partition table has been altered!

Calling ioctl() to re-read partition table.

WARNING: Re-reading the partition table failed with error 16: Device or resource busy.
The kernel still uses the old table. The new table will be used at
the next reboot or after you run partprobe(8) or kpartx(8)
Syncing disks.
[root@localhost ~]# reboot

Show the current size of the Physical Volume

pvdisplay
[root@localhost ~]# pvdisplay
  --- Physical volume ---
  PV Name               /dev/xvda2
  VG Name               VolGroup
  PV Size               7.51 GiB / not usable 3.00 MiB
  Allocatable           yes (but full)
  PE Size               4.00 MiB
  Total PE              1922
  Free PE               0
  Allocated PE          1922
  PV UUID               zKmGEt-Uf0A-I14h-NDYc-53rf-micT-VxNqsP
   
[root@localhost ~]#

Resize the Physical Volume

pvresize /dev/xvda2
[root@localhost ~]# pvresize /dev/xvda2
  Physical volume "/dev/xvda2" changed
  1 physical volume(s) resized / 0 physical volume(s) not resized
[root@localhost ~]#

Run pvdisplay again.  You should see more space under PV Size.

[root@localhost ~]# pvdisplay
  --- Physical volume ---
  PV Name               /dev/xvda2
  VG Name               VolGroup
  PV Size               11.51 GiB / not usable 2.08 MiB
  Allocatable           yes 
  PE Size               4.00 MiB
  Total PE              2945
  Free PE               1023
  Allocated PE          1922
  PV UUID               zKmGEt-Uf0A-I14h-NDYc-53rf-micT-VxNqsP
   
[root@localhost ~]#

Notice the “Free PE” section above.  If it says 0 then you won’t be able to run the next command.

Resize LVM

the “+100%FREE” part of the command tells it to uses up all of the free space available

lvresize /dev/VolGroup/lv_root -l +100%FREE
[root@localhost ~]# lvresize /dev/VolGroup/lv_root -l +100%FREE
  Extending logical volume lv_root to 10.71 GiB
  Logical volume lv_root successfully resized
[root@localhost ~]#

Resize the File System

resize2fs /dev/VolGroup/lv_root
[root@localhost ~]# lvresize /dev/VolGroup/lv_root -l +100%FREE
  Extending logical volume lv_root to 10.71 GiB
  Logical volume lv_root successfully resized
[root@localhost ~]#

And that is it.  Check out the extra space.

[root@localhost ~]# df -h /
Filesystem                    Size  Used Avail Use% Mounted on
/dev/mapper/VolGroup-lv_root   11G  733M  9.3G   8% /
[root@localhost ~]# exit

How to Boot a XenServer VM into Recovery Mode

Posted on by
Reply

Recovery Mode can be helpful if you need to do certain task like operate on the VM with the disk unmounted or you need to reset a root password.

All of the following is done through XenCenter

To boot the VM into recovery mode all you have to do is

  1. Shutdown the VM
  2. Insert boot media i.e. (DVD, cd, iso image, etc.) into DVD Drive 1:
  3. Start VM in Recovery Mode.  In the main menu click on VM –> Start/Shut Down –> Start in Recovery Mode

When the VM boots up it will boot off of whatever is in DVD Drive 1.