4.3 Creation of VM

Posted Jan 21, 2026

By So Hee Park 8 min read

✅ Create a new VM

Maquina > New

We have to decide if the machine will be created in internal or external disk
the HW is given by the host
VM
changing BIOS -> checkbox named EFI
file .vdi

✅ HW for the VM is given by the host

1️⃣ RAM(RAM without SWAP)
❓ As a host, how much of my RAM should I give to the VM?
👉🏻 half
the RAM of the VM must be maximum of the half of the real machine
if you give more than half, the real RAM will suffer
VM RAM = max 1/2 of the RM RAM
⭐️ Sometimes VM can run better if you give less RAM
as I give more RAM to the real host machine
and the real machine can push the booting process
2️⃣ Cores
❓ As a host, if I have several cores in my CPU, how many cores should I give to the VM?
👉🏻 half
VM cores = max 1/2 of the RM cores
sometimes VM need increased/decreased number of cores
so it depends
3️⃣ BIOS
❓ If RM has legacy BIOS, can VM have UEFI BIOS?
YES! VM can be anything
👉🏻 Regardless of BIOS in RM, VM can have any BIOS, legacy or UEFI
There is a UEFI simulator
This simulation is activated with a checkbox EFI
so click on the EFI checkbox
4️⃣ Harddisk
👉🏻 minimum necessary
VM HD = miminum
The portion of the HD that VM uses
is isolated from the rest
bc that part of the portion is not a partition
but it will be lots of files, in a separate part
and the files will be encrypted
👍🏻 so all the other files in the host will be protected
so files of VM and the files that are not are separated
👍🏻 protect host from infections from virus
that file is called .vdi
✔️ .vdi
that file that you create for the VM are called .vdi
portion of the HD for the VM
will be represented with a red cube 🟥
so you can make a worm in the VM, and the other
✔️ Scaffold

the .vbox is also known as scaffold, settings
settings for the VM(like the RAM capacity, EFI, Cores)
✔️ .vbox

scaffolding for VM
the settings for the VM
this depends on each computer

settings of the hardware that I dedicate to the guest has the extension .vbox
settings of the hardware that I dedicate to VM are stored in settings file with extension .vbox
the settings of the host that I dedicate to the VM are stored in the file with a extension .vbox
with a blue cube 🟦
each host computer has its own scaffold
each host has different access to the VM
the accesses to the machine
In Virtual Box
in the left side, you have the scaffolds, accesses to the machine
If you right click on one scaffold
and click on option show in explorer
you will reach the .vbox and the .vdi file
the machine only with .vdi can be repaired
you just create a new scaffold
⚠️ but a machine only with .vbox is lost forver
bc .vbox only contains the settings
💡 The application, the extension pack and the **link between them **should be installed in every host machines

✅ Where are you going to create the VM?

1️⃣ Internal disk

if you created a VM in the internal disk of your computer,
.vdi .vbox are both inside the internal disk of your computer
❓ Where? both are inside C\Users\<user>\VirtualBox VMs folder
inside this folder, you will have one sub folder for each machine

if you move your folder from there
the access to VM will be unaccessible
so just do not move them, keep it there
the .vbox keeps the file of that VM computer

2️⃣ External disk

👍🏻 portable
if you created a VM in the external disk of your computer,
the .vdi .vbox are in the external disk
as the external disks do not have the strcuture
we should create manually VirtualBox VMs folder hanging from the root
inside the folder, there will one subfolder per VM machine
the .vbox file, although it is inside the external fisk
it will contain the settings for the host computer
so if you change the host computer
the .vbox file will not be valid, depending on the host
so if you change the host computer, you need to adapt the .vbox to the new host
ofc, the .vbox will work if several host computer settings are the same or compatible
If you create a VM on the external disk
you can bring the external disk home
but then you should install/guarantee the following
💡 the application, the extension pack and the perfect the link has to be done in all computers

thunder means half

📌 Cheatsheet

✔️ C:\Windows\System32\drivers

traces, only delete if necessary
delete VBox*.sys
then reinstall VirtualBox

✔️ C:\Usuarios\<usuario>\.VirtualBox

traces, only delete if necessary
then reinstall VirtualBox

✔️ C:\Usuarios\<usuario>\VirtualBox VMs

my VM, my .vbox and .vdi files

✔️ VirtualBox.exe

installation program for Virtual Box
when you download, it will be in the downloads the folder
do not double click
run as admin

✔️ vbox-extpack

extension pack
when you download, it will be in the downloads the folder
do not double click
find it in the C:\File > tools > extension and link it

✔️ <filename>.iso

the installer of the application or OS
that you want to have on your VM
do not double click
when you have a .iso, you have two options
(1) be in front of your computer when you install the OS
(2) unattended install
- if you do not want unattended install,
- some computers have a tick named omit unattended
- some computers have a tick named proceed with unattended
- if I do not want unattended: click on omit
- if I do not want unattended: do not click on proceed
- ⚠️ a mistake here has no return

✅ Size of `.vdi`

can be given in two ways
1️⃣ Full Size
give those bytes at once
creation of VM will be slower
but then after creation
fast access
🛠️ We know how much capacity we need
2️⃣ Dynamic Size
get the minimum bytes
then increase later
creation of VM will be faster
but then after creation
access will be slower
🛠️ If we do not know if we are going to use the complete capacity
we do not know the capacity we need

✅ VM Name

the name of the VM should always contain
all the information about the VM
name should contain:
creator
what group does this machine belong to
the content and characteristics(version, edition…) of the machine
first letter of each word in capital
no space in names
no accents, no strange characters
👀 DW1E_DualBootingLinWinLimited_SoHeePark

📢 Exercise 1

- SoHee is a customer with a old computer, with a legacy
- She has 100GB space in her HD
- and she wants to try both linux + windows
- a lin-win, strong in windows, and the least in linux
- and she does not know how much VM she will use, maybe 100GB
- we want internal disk

1️⃣ First Window: Name and OS

✔️ Name

💡 Important rule: the name of the VM must include all the information of the OS
the name should be DW1E_DualBootingLinWinLimited_SoHeePark

✔️ Folder selection

the folder selection is where we decide if we want internal or external
for internal, it should be C:\Users\Vespertino\VirtualBox VMs
for internal, just do not touch it
for external, click on the drop down and navigate to your external disk, and select the external disk D:\VirtualBox VMs
and when you select smth, and undo it, then redo it
better just start anew
this happens bc virtual box is programmed in linux
so it does not have been thouroughly tested
no company behind to certify everything

✔️ iso

.iso image file is the file you want to use for building your new system
choose GPartEd.iso
first .iso should be GPartEd iso
then install Windows with windows.iso
then linux.iso…

✔️ Edition, type, subtype

edition, type, subtype should be completed by default, do not change
if not completed by default, you have to complete it manually
and do not make errors, typos
👀 You want windows 10 32 bits iso, type needs to be windows
👀 subtype needs to be 10
👀 version needs to be 32
with error in edition, type, subtype, your VM will never work
we do not want unattened install
omit it

2️⃣ Second Window: Hardware

RAM: half
Core: half
EFI is going to change depending on the moment
now we have GPartEd
so do not click EFI

3️⃣ Third Window: Disk size

disk size
choose the size of the vdi
choose 100G
If it does not let me choose full size, it is bc dynamic size is chosen by defualt
choosing dynamic size is a good decision, as Soso does not know how much she wants to use
do not choose full size

DAW bilingual, Computer System

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