VirtualBox Notes

• 1. VirtualBox Guest Addtion on CLI
• 2. Optimize VirtualBox VM Disk Space
• 3. Troubleshooing VirtualBox VM
  • 3.1. Unable to mount Shared folders in CLI

1. VirtualBox Guest Addtion on CLI

• Mount Guest Addtion ISO (from Console Menu)
• Mount it from OS (/vmboxguestiso is destination mount point)

  mount /dev/cdrom /vmboxguestiso/
  

• Resolve Dependancies

Install kernel-header

`sudo yum update && sudo yum -y install kernel-headers kernel-devel`

## install other packages
yum install gcc make perl

2. Optimize VirtualBox VM Disk Space

1. Clean up inside the VM

$ sudo dnf clean all
$ sudo journalctl --vacuum-time=7d
$ sudo rm -rf /var/cache/*
$ sudo rm -rf ~/.cache/*

1. Zero out the free space

$ sudo dd if=/dev/zero of=/zerofile bs=1M
dd: error writing '/zerofile': No space left on device
107617+0 records in
107616+0 records out
112843751424 bytes (113 GB, 105 GiB) copied, 127.059 s, 888 MB/s

$ sudo rm -f /zerofile

1. Shutdown the VM

$ sudo shutdown -h now

1. Run VBoxManage to compact the disk

VirtualBox does not support compacting .vmdk disks directly. Convert your .vmdk disk to .vdi, compact it, and then continue using the compacted disk.

 $  VBoxManage clonehd \
  "/path/to/vm-folder/aap25-rhel92-1/generic-rhel9-virtualbox-disk001.vmdk" \
  "/path/to/vm-folder/aap25-rhel92-1/aap25-compact.vdi" \
  --format VDI
0%...10%...20%...30%...40%...50%...60%...70%...80%...90%...100%
Clone medium created in format 'VDI'. UUID: 6517df59-9cd0-4393-bb03-c5d182219cc3

Now run the compact vdi command.

$  VBoxManage modifymedium "/home/gmadappa/VirtualBox VMs/aap25-rhel92-1/aap25-compact.vdi" --compact
0%...10%...20%...30%...40%...50%...60%...70%...80%...90%...100%

3. Troubleshooing VirtualBox VM

3.1. Unable to mount Shared folders in CLI

Check vboxsf module sudo modprobe vboxsf