VirtualBox¶

• VirtualBox
• Introduction
• Storage
  • Fix Linux guest file system full
  • Migrating Xen DomU (un-partitioned LV for /) to VirtualBox
• systemd: start VMs at host boot and shut down during host shutdown
  • Script
  • /etc/systemd/system/vboxvmservice@.service
  • Instantiation

Introduction¶

Here are miscellaneous techniques used on Debian VirtualBox hosts

Storage¶

Fix Linux guest file system full¶

Increasing the size of the .vdi is routine. The challenge is re-partitioning to use the extra space. Most solutions found on the Internet have the guest booting a gparted .iso. A more convenient solution uses qemu's nbd.

• Ensure the qemu-utils package is installed

•  
  modprobe nbd
  

• Ensure the .vdi is not in use
• Create the network block device (NBD)
  

  qemu-nbd -c /dev/nbd0 <path of .vdi file>
  

• Adjust the partition table. Example
  

  parted /dev/nbd0
  ...
  (parted) print free
  ...
  (parted) resizepart 4 100%
  ...
  

• If growing the file system on the host instead of the guest, example for partition 4
  

  e2fsck -f /dev/nbd0p4
  ...
  resize2fs /dev/nbd0p4
  ...
  

• Disconnect the NBD
  

  qemu-nbd -d /dev/nbd0
  

Migrating Xen DomU (un-partitioned LV for /) to VirtualBox¶

Scenario: a Xen DomU using an un-partitioned LV for its / file system and booting via pygrub was to be migrated to VirtualBox.

Converting to .vdi was easy using VBoxManage convertfromraw <path of LV image> <path of output .vdi> --format VDI but no way was found to make VirtualBox boot the .vdi

The workaround was:

• Add a new .vdi to the VM definition
• Fresh OS installation to the new .vdi thus creating a conventional bootable partitioned layout
• Boot the VM from standalone media
• Sync files from the conversion output .vdi to the new .vdi

systemd: start VMs at host boot and shut down during host shutdown¶

Script¶

/usr/local/bin/shut_down_vbox_vm.sh

/etc/systemd/system/vboxvmservice@.service¶

This is specific to the User= user

[Unit]
Description=VBox Virtual Machine %i Service
Requires=systemd-modules-load.service
After=systemd-modules-load.service

[Service]
User=c
Group=vboxusers
ExecStart=/usr/bin/VBoxManage startvm %i --type headless
ExecStop=/usr/local/bin/shut_down_vbox_vm.sh %i
RemainAfterExit=yes

[Install]
WantedBy=multi-user.target

Instantiation¶

Example, for user c's VM aems3.iciti.av

# systemctl enable vboxvmservice@aems3.iciti.av