Virtualbox Disk Reduce or Disk Compact

You have to do the following steps:

1. Run defrag in the guest (Windows only)

Nullify free space: With a Linux Guest run this:

sudo dd if=/dev/zero of=/bigemptyfile bs=4096k
sudo rm -rf /bigemptyfile


telinit 1
mount -o remount,ro /dev/sda1
zerofree -v /dev/sda1


sudo apt-get install secure-delete
sfill -f -z -l -l -I -v /

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Cloning Openvz Proxmox PVE container guest machine

  1. I first created a ‘template’ vm containing all stuff I need and using a temporarily ip adres.
  2. In the network config file of eth0 (/etc/sysconfig/network-scripts/ifcfg-eth0) I comment out the HWADDRESS line, else it will not come up with another mac address…
  3. Stop this ‘template’ vm as it is just used for cloning.
  4. Create a backup : vzdump –dumpdir /path/to/backupdir –snapshot 101
  5. Restore in new container : vzrestore /path/to/backupdir/backupfile_of_container_101 102 or vzrestore –storage ‘storagename’ /path/to/backupdir/backupfile_of_container_101 102
  6. Create a new mac for eth0 : vzctl set 102 –netif_add eth0
  7. Modify the hostname in the proxmox webinterface.
  8. Bootup the vm and open a vnc console.
  9. Change the ip address in /etc/sysconfig/network-scripts/ifcfg-eth0
  10. Go to /etc/ssh and remove all keys : rm -f /etc/ssh/*key*
  11. Restart the ssh server so it will regenerate keys : service sshd restart

Allow NFS attachment on Proxmox OpenVZ containers

Prepare the container

To allow a container to use NFS filesystem, you will need to start it with “nfs” feature enabled. If the container is running while you set the –features nfs:on, you will need to reboot it.

# vzctl set 101 --features "nfs:on" --save
# vzctl start 101

After this you may see nfs in /proc/filesystems

# vzctl exec 101 cat /proc/filesystems
nodev rpc_pipefs
nodev proc
nodev nfs
nodev sysfs
nodev tmpfs
nodev devpts

Set date/time permanently on Virtualbox Guest

First you need to ssh to the server and be root and then do these step by step:

1. Set the date/time as following format

# date -s “2 OCT 2013 18:00:00″

2. Set the proper Timezone for your area-

# cd /etc
# ln -sf /usr/share/zoneinfo/EST localtime

3. Set it to the BIOS for permanent stamp-

# /sbin/hwclock –systohc

On Debian/Ubuntu sytem:

dpkg-reconfigure tzdata

BDST NTP Server:

Fix Date Time on PVE OpenVZ Guest machine

  1. Stop VE vzctl stop 101
  2. in HD node, run:
  3. vzctl set 101 –capability sys_time:on –save
  4. Start VE: vzctl start 101
  5. Enter VE: vzctl enter 101
  6. mv /etc/localtime /etc/localtime.old
  7. ln -s /usr/share/zoneinfo/Asia/Dhaka /etc/localtime
  8. date 092115442006 (09 = Month, 21 = day, 15 = hour, 44=minutes, 2006 = year)

Run date to check your time is right. That’s it!


VBoxHeadless Running Virtual Machines With VirtualBox On A Headless Debian/ubuntu Server

I have implemented this on Debian 6 (Squeeze system) with the IP address where I’m logged in as root.

Installing VirtualBox To install VirtualBox 4.1 on our Debian server, we open /etc/apt/sources.list… added this line-

deb squeeze contrib non-free

Use appropriate OS source list from

Then we download the VirtualBox public key…

wget -q -O- | apt-key add -

… and update our package database: sudo apt-get update

Afterwards, we install VirtualBox 4.1 as follows:

apt-get install linux-headers-$(uname -r) build-essential virtualbox-4.1 dkms

(The dkms package ensures that the VirtualBox host kernel modules are properly updated if the Linux kernel version changes.) Starting with version 4.0, VirtualBox has introduced so called “extension packs” and has outsourced some functionality like remote desktop connection support (VRDP) that was part of VirtualBox packages before version 4.0 into these extension packs. Because we need remote desktop connections to control our virtual machines, we need to install the appropriate extension pack now. Go to, and you will find a link to the following extension pack: VirtualBox 4.1.18 Oracle VM VirtualBox Extension Pack Support for USB 2.0 devices, VirtualBox RDP and PXE boot for Intel cards. Download and install the extension pack as follows:

cd /tmp
VBoxManage extpack install Oracle_VM_VirtualBox_Extension_Pack-4.1.18-78361.vbox-extpack

(Make sure you grab the latest version from the VirtualBox web site.) Restart the Server at this stage to update the kernel with virtualbox optimized. Installing phpvirtualbox First create a system user called vbox and add it to the vboxusers group:

useradd -m vbox -G vboxusers

Create a password for the vbox user:

passwd vbox

Create the file /etc/default/virtualbox and put the line


in it (so that the VirtualBox SOAP API which is called vboxwebsrv runs as the user vbox): vi /etc/default/virtualbox VBOXWEB_USER=vbox Next create the system startup links for vboxwebsrv and start it:

update-rc.d vboxweb-service defaults
/etc/init.d/vboxweb-service start

Now, run the following command to check if virtualbox kernel modules are loaded or not.

sudo systemctl status vboxdrv


sudo /etc/init.d/vboxdrv status

Sample output:

vboxdrv.service - VirtualBox Linux kernel module
Loaded: loaded (/usr/lib/virtualbox/; enabled; vendor preset: enabled)
Active: active (exited) since Thu 2015-11-26 16:38:30 IST; 42s ago

Nov 26 16:38:29 server systemd[1]: Starting VirtualBox Linux kernel module...
Nov 26 16:38:30 server systemd[1]: Started VirtualBox Linux kernel module.
Nov 26 16:38:30 server[15008]: Starting VirtualBox kernel modules....
Hint: Some lines were ellipsized, use -l to show in full.

If it, not loaded, run the following command to load them:

sudo /etc/init.d/vboxdrv setup

We need a web server with PHP support to serve phpvirtualbox – I’m using Apache2 here. Install Apache2 and PHP5 as follows:

apt-get install apache2-mpm-prefork apache2-utils apache2.2-bin apache2.2-common apache2 apache2-doc apache2-suexec libapache2-mod-php5 libapr1 libaprutil1 libaprutil1-dbd-sqlite3 libaprutil1-ldap libapr1 php5-common php5-mysql php5-suhosin php-pear wget

for Ubuntu you may install Apache-PHP with folliwng packages-

apt-get -y install apache2 php5-mysqlnd php5-curl php5-gd php5-intl php-pear php5-imagick php5-imap php5-mcrypt php5-memcache php5-ming php5-ps php5-pspell php5-recode php5-snmp php5-sqlite php5-tidy php5-xmlrpc php5-xsl php5 libapache2-mod-php5

For Ubuntu 16 use the following packs:

apt-get install php libapache2-mod-php php-mcrypt php-mysql  php-xml php-soap

Restart Apache2:

/etc/init.d/apache2 restart

Now, start vboxweb-service, and make it to start automatically on every reboot.

sudo systemctl status vboxweb-service


sudo /etc/init.d/vboxweb-service start

Sample output:

Starting VirtualBox web service ...done.

I want to serve phpvirtualbox from Apache’s default virtual host with the document root /var/www (I will install it in /var/www/phpvirtualbox) – if you have a different document root, you must adjust the following steps: cd /var/www wget Unzip phpvirtualbox and rename the phpvirtualbox-4.1-7 to phpvirtualbox for ease of use: unzip mv phpvirtualbox-4.1-7 phpvirtualbox Next go to the /var/www/phpvirtualbox/ directory… cd /var/www/phpvirtualbox/ … and create the file config.php by copying it from config.php-example: cp config.php-example config.php Open config.php and fill in the password you created earlier for the vbox system user: vi config.php […] /* Username / Password for system user that runs VirtualBox */ var $username = ‘vbox’; var $password = ‘secret’; […] That’s it already – you can now open a browser and access phpvirtualbox as follows:

Optional Task

Removing & updating Virtualbox Extension Pack:

For example removing virtualbox extension pack 4.3 to 5.1 version, do the following things-

$ VBoxManage list extpacks
Extension Packs: 1
Pack no. 0: Oracle VM VirtualBox Extension Pack
Version: 4.1.12
Revision: 77218
Description: USB 2.0 Host Controller, VirtualBox RDP, PXE ROM with E1000 support.
Usable: true
Why unusable:

How to remove an extension pack:

$ VBoxManage extpack uninstall "Oracle VM VirtualBox Extension Pack"
Successfully uninstalled "Oracle VM VirtualBox Extension Pack".