File Locations

Cubic keeps everything a VM instance owns in one directory and shares the downloaded images in a cache. Both live in your own user directories, so no command needs elevated rights.

Instance Directory

Each VM instance has its own directory named after it:

Platform	Path	Typical value
Linux	$XDG_DATA_HOME/cubic/machines/<instance>	~/.local/share/cubic/machines/<instance>
Snap	$SNAP_USER_COMMON/cubic/machines/<instance>	~/snap/cubic/common/cubic/machines/<instance>
macOS	$HOME/Library/cubic/machines/<instance>	~/Library/cubic/machines/<instance>
Windows	%LOCALAPPDATA%\cubic\machines\<instance>	C:\Users\<user>\AppData\Local\cubic\machines\<instance>

Files in an Instance Directory

File	Content
instance.toml	Settings of the VM instance and the stored SSH host key of the guest. Every field is listed in Instance File.
machine.img	Disk image in qcow2 format, including its snapshots.
ssh_client_key	Private SSH key of the VM instance.
cloud-init.iso	Seed image cloud-init reads on the first boot. Its content is listed in Guest Configuration.
qemu.pid	Process id of QEMU. Present while the VM instance runs.
ca-cert.pem, server-cert.pem, server-key.pem, client-cert.pem, client-key.pem	Certificates of the mutual TLS connection to the QEMU monitor and the serial console.

Image Cache

Downloaded distribution images are shared by every VM instance that uses them:

Platform	Path	Typical value
Linux	$XDG_CACHE_HOME/cubic	~/.cache/cubic
macOS	$HOME/Library/Caches/cubic	~/Library/Caches/cubic
Windows	%TEMP%\cubic	C:\Users\<user>\AppData\Local\Temp\cubic

The directory holds images with one file per image, named <distribution>_<release>_<architecture> such as ubuntu_resolute_amd64, and images.cache with the image list Cubic downloaded last.