Virtual machine maintenance

While using virtual box, we will face the below issues.

• Disk space Shortage: When you are running out of space in linux/windows machine.
• Moving Virtual machine to other machine: When you want to move your virtual machine to another laptop.

1. Increasing virtual machine space:

Shut down the Virtual box.

Note down the virtual hard disk path.

Go to Start →Run → CMD

Navigate to the virtual box installation directory where the utility VBoxManage present

Now enter the below command to increase virtual Disk size. Replace 20000  (MB) with the size you want.

VBoxManage modifyhd E:\Practice\Fedora20.vdi --resize 20000

Now we increased the Disk space. Check in virtual box once.

Space was increased as expected.

Now, we will increase space in fedora. The storage changes are not reflected in fedora until we manually 
increase the filesystem.

We have to manually extend the space.

[root@localhost ~]# fdisk -l /dev/sda

Disk /dev/sda: 19.5 GiB, 20971520000 bytes, 40960000 sectors

Units: sectors of 1 * 512 = 512 bytes

Sector size (logical/physical): 512 bytes / 512 bytes

I/O size (minimum/optimal): 512 bytes / 512 bytes

Disklabel type: dos

Disk identifier: 0x000de218

Device    Boot     Start       End   Blocks  Id System

/dev/sda1 *         2048   1026047   512000  83 Linux

/dev/sda2        1026048  25165823 12069888  8e Linux LVM

Note down the Id of your partition.

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

Welcome to fdisk (util-linux 2.24).

Changes will remain in memory only, until you decide to write them.

Be careful before using the write command.

Command (m for help): p

Disk /dev/sda: 19.5 GiB, 20971520000 bytes, 40960000 sectors

Units: sectors of 1 * 512 = 512 bytes

Sector size (logical/physical): 512 bytes / 512 bytes

I/O size (minimum/optimal): 512 bytes / 512 bytes

Disklabel type: dos

Disk identifier: 0x000de218

Device    Boot     Start       End   Blocks  Id System

/dev/sda1 *         2048   1026047   512000  83 Linux

/dev/sda2        1026048  25165823 12069888  8e Linux LVM

Command (m for help): n

Partition type:

  p   primary (2 primary, 0 extended, 2 free)

  e   extended

Select (default p): p

Partition number (3,4, default 3): 3

First sector (25165824-40959999, default 25165824):

Last sector, +sectors or +size{K,M,G,T,P} (25165824-40959999, default 40959999):

Created a new partition 3 of type 'Linux' and of size 7.5 GiB.

Command (m for help): t

Partition number (1-3, default 3): 3

Hex code (type L to list all codes): 8e

Changed type of partition 'Linux' to 'Linux LVM'.

Command (m for help): w

The partition table has been altered.

Calling ioctl() to re-read partition table.

Re-reading the partition table failed.: 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).

Reboot the machine.

[root@localhost ~]# fdisk -l /dev/sda

Disk /dev/sda: 19.5 GiB, 20971520000 bytes, 40960000 sectors

Units: sectors of 1 * 512 = 512 bytes

Sector size (logical/physical): 512 bytes / 512 bytes

I/O size (minimum/optimal): 512 bytes / 512 bytes

Disklabel type: dos

Disk identifier: 0x000de218

Device    Boot     Start       End   Blocks  Id System

/dev/sda1 *         2048   1026047   512000  83 Linux

/dev/sda2        1026048  25165823 12069888  8e Linux LVM

/dev/sda3       25165824  40959999  7897088  8e Linux LVM

[root@localhost ~]# pvdisplay

 --- Physical volume ---

 PV Name               /dev/sda2

 VG Name               fedora

 PV Size               11.51 GiB / not usable 3.00 MiB

 Allocatable           yes (but full)

 PE Size               4.00 MiB

 Total PE              2946

 Free PE               0

 Allocated PE          2946

 PV UUID               escjAW-rsyC-oKh2-nMtZ-WBfW-vd21-WD11rO

[root@localhost ~]# pvcreate /dev/sda3

 Physical volume "/dev/sda3" successfully created

[root@localhost ~]# pvdisplay

 --- Physical volume ---

 PV Name               /dev/sda2

 VG Name               fedora

 PV Size               11.51 GiB / not usable 3.00 MiB

 Allocatable           yes (but full)

 PE Size               4.00 MiB

 Total PE              2946

 Free PE               0

 Allocated PE          2946

 PV UUID               escjAW-rsyC-oKh2-nMtZ-WBfW-vd21-WD11rO

 "/dev/sda3" is a new physical volume of "7.53 GiB"

 --- NEW Physical volume ---

 PV Name               /dev/sda3

 VG Name

 PV Size               7.53 GiB

 Allocatable           NO

 PE Size               0

 Total PE              0

 Free PE               0

 Allocated PE          0

 PV UUID               mTNEcF-wQbO-oOmL-Ss29-QU4Q-fnwH-kcPVEi

[root@localhost ~]# vgdisplay

 --- Volume group ---

 VG Name               fedora

 System ID

 Format                lvm2

 Metadata Areas        1

 Metadata Sequence No  3

 VG Access             read/write

 VG Status             resizable

 MAX LV                0

 Cur LV                2

 Open LV               2

 Max PV                0

 Cur PV                1

 Act PV                1

 VG Size               11.51 GiB

 PE Size               4.00 MiB

 Total PE              2946

 Alloc PE / Size       2946 / 11.51 GiB

 Free  PE / Size       0 / 0

 VG UUID               bQ3KIS-pDYO-LRXH-DMVt-1kVm-IEoN-yNhGdv

[root@localhost ~]# vgextend fedora /dev/sda3

 Volume group "fedora" successfully extended

[root@localhost ~]# lvextend /dev/fedora/root /dev/sda3

 Extending logical volume root to 17.84 GiB

 Logical volume root successfully resized

[root@localhost ~]# resize2fs /dev/fedora/root

resize2fs 1.42.8 (20-Jun-2013)

Filesystem at /dev/fedora/root is mounted on /; on-line resizing required

old_desc_blocks = 1, new_desc_blocks = 2

The filesystem on /dev/fedora/root is now 4675584 blocks long.

[root@localhost ~]# df -h

Filesystem               Size  Used Avail Use% Mounted on

/dev/mapper/fedora-root   18G  3.0G   14G  18% /

devtmpfs                 1.3G     0  1.3G   0% /dev

tmpfs                    1.3G  148K  1.3G   1% /dev/shm

tmpfs                    1.3G  708K  1.3G   1% /run

tmpfs                    1.3G     0  1.3G   0% /sys/fs/cgroup

tmpfs                    1.3G   16K  1.3G   1% /tmp

/dev/sda1                477M   81M  368M  18% /boot

Now the space was extended in the Fedora also.

2. Moving Virtual machine:

We need to move virtual machine when we running out of space in one drive or we have brand new
laptop with us.

Here is the steps that help you to move the virtual machine.

We can move the virtual machine in two ways.

1. Export and import
2. Manually copying virtual hard disk.

1. Export and import

We will see how to export and import virtual machine in virtual box.

Choose the virtual machine

Go to File →Export appliances

Click Next

Choose the export file destination and click next

Click Export.

When it is finished, OVA file will be generated at the destination location.

Now you can use this OVA file to recreate virtual machine in another machine.

Import virtual machine.

To demonstrate how import is going to work, I will delete existing virtual machine and import it from 
OVA file.

Open  Virtual box. Go to file → Import appliances

And click Open appliance

Choose the OVA file.

Click NEXT.

Check the virtual machine settings once.

I recommend to check RAM size and virtual disk location values before importing

Now click Import.

And virtual machine successfully imported.

If you face the below error while importing the virtual machine.

Uncheck the DVD and USB controller options and import it again.

2. Manually copying virtual hard disk

You simply copy the VDI file from one machine to another machine to move the virtual machine
to another machine. Choose to create a new virtual machine.

And select Use an existing virtual hard drive file option and choose the VDI/VMDK file.

And click create. Now the virtual machine will create using existing virtual hard disk.

After creating virtual machine, please check virtual machine settings once.