Virtual machines

12 min · 12 sections

A NAS with spare memory and space is the machine in the house where it makes sense to run another computer inside: a Windows for that program that only exists on Windows, a throwaway Linux you can break without fear, or the old system you still need once a year. All from the browser, without installing anything on any other computer.

Each machine belongs to whoever creates it. Whoever administers decides who gets the app; from there, each person sees their own and the ones shared with them. A machine's "Share" button lets you choose "Can view" (see how it is doing) or "Can use it" (also start it, shut it down and use its screen). Alerts about an account's machine do not go out through the household email or channels. The machines that already existed stay within reach of whoever had the app.

You need a volume already created (Storage → Create volume): machine disks are big files and live on the volume, under <pool>/vm/<name>/, never on the system disk. And the NAS should be a real machine: if LGM-OS itself runs inside another virtual machine there is no hardware acceleration (KVM) and everything crawls at emulator speed — the machine's screen warns about it.

The first machine

1. Get the installation image (the .iso file of the system you want) and **import it: in Virtual machines → New machine, the "Import an ISO from this computer"** button uploads it to the NAS's image store and leaves it selected. Uploading it to any household folder from Files works too: it shows up in the selector all the same.
2. "New machine": name, processors (2 by default), memory (2 GB by default), disk (32 GB by default — it is a file that only takes up what the machine writes, not the whole 32 GB up front) and the ISO.
3. The machine boots from the CD and the system installer appears: you drive it from the screen, as if you had a keyboard and monitor plugged in.
4. When the install finishes, eject the CD (the eject button on the machine's card, or in Details). While it is in, every reboot launches the installer again — it is the classic slip, which is why the card flags it with "boots from the CD".

The machine's disk grows up to the cap you gave it, but the cap cannot shrink. Start tight: growing it later is a button (Make the disk bigger); shrinking does not exist.

The screen

The "Screen" button opens the machine's console right in the panel — what you would see on a monitor plugged into it, from the BIOS to the desktop. It can also open in a separate tab, full screen.

• The console is not left open on the network: the machine only shows it to the NAS itself, and the panel acts as an authenticated bridge. Nobody on the local network can peek at it.
• The mouse stays aligned (the machine carries a virtual tablet): the pointer inside matches the one outside, with no weird captures.
• With the machine powered off, the screen says so and waits: as soon as it starts —from here, by its schedule or from another device— it shows up by itself, without opening it again.
• If the connection drops, it tries again on its own. If it still does not come back, check the machine is still running and open the screen again.

The screen is for installing and for getting out of trouble. For day-to-day use inside the machine, its own remote access is more comfortable (SSH on a Linux, Remote Desktop on a Windows), entering through its IP.

Powering on, off, and starting with the NAS

• Shut down asks it nicely, like the power button on a PC: the system inside saves and closes. If after two minutes it has not obeyed, the panel says so — on a Linux without acpid, or a Windows with the power button set to "do nothing", the request falls on deaf ears.
• Force power off is pulling the plug: anything unsaved inside is lost. Only when it ignores a normal shutdown.
• Starts with the NAS: the autostart switch makes the machine come up on its own every time the NAS powers on. For the machine that serves something, it is the difference between "always works" and "works until the first power cut".

The machine's network

You choose how it connects in Details → hardware, and the panel only offers what actually exists on your machine:

• Virtual network (the usual): the machine reaches the internet and the NAS sees it, but the rest of the house cannot reach it. Perfect for installing and for throwaway machines.
• Bridge: the machine connects as one more computer on your network — your router gives it an IP, other computers see it. It is what you want if the machine serves something to the house. The docker0 bridge puts it on the same network as the Docker containers.
• Direct on a card: for specific cases; the machine shares the NAS's physical card.

The machine's IP shows up in Details, without entering it: the panel asks the guest agent if the system carries it, and otherwise the virtual network's registry.

USB devices

A machine running a home-automation system (Home Assistant and friends) needs the Zigbee or Z-Wave stick plugged into the NAS. Under Details → Network, CD and devices you get the USB devices connected to the NAS: tick the one you want and the virtual machine will see it as if it were plugged into the machine itself.

⚠️ While the machine is running, the device is its own: the NAS and its apps stop seeing it. If you have that same stick registered with an app from the store, take it away from the app first or the two will fight over it.

The rest worth knowing:

• Like all hardware, the change takes effect when the machine starts (and can only be edited with the machine powered off).
• The device is identified by its model, not by the port: you can unplug it and plug it into another USB socket and the machine will still find it. In exchange, with **two identical devices** the panel warns you: there is no way to tell them apart and one is handed over.
• If the device is not plugged in when the machine starts, **the machine starts without it**: plug it in and restart the machine so it sees it. The panel does not let you tick one that is not plugged in, so you never count on something that is not there.
• A keyboard or a mouse plugged into the NAS also show up in the list. Do not tick them: the NAS would be left without them.

Hardware after creating it

Everything in Details, and only with the machine off — changing hardware under a running system is the fastest way to corrupt it. You can change memory, processors, the CD's ISO and, under "advanced hardware": firmware (BIOS or UEFI), secure boot, TPM 2.0 chip, the processor model (the NAS's own, as is, which is the fast one, or a generic one that lets the machine move to another computer) and the graphics card (QXL the usual; VirtIO for modern Linux; VGA the one everything accepts).

Make the disk bigger

The "Make it bigger" button adds gigabytes to the disk (it never sets a size: a slip downwards is something nobody can undo). Mind the second half, which is on you: this gives more disk to the machine, not to its partitions — inside, Windows or Linux keep seeing the old partition until you grow it with their own tool (Disk Management on Windows, growpart/GParted on Linux).

Cloning a machine

Under Details, with the machine powered off, the "Clone…" button asks for a name and makes another machine just like it. It is what you want for a "base Windows" the kids' machines come out of, or to try an update on a copy before touching the good one.

The whole disk is copied, so it can take from a few minutes to well over an hour —it depends on how much the disk holds— and you will see it progress on a desktop card; you can keep using the NAS meanwhile.

The copy is born powered off, not starting with the NAS, and with three things changed on purpose:

• A new network card. Two machines with the same hardware address fight over the same IP and neither works properly. The clone will ask for its own when you switch it on.
• Without the USB devices the original had: one can only be attached to a single machine at a time. If the clone needs it, hand it over from its own card with the other one off.
• A fresh TPM, if the original had one (Windows 11). If BitLocker was enabled inside, Windows will ask for the recovery key the first time the clone starts.

Snapshots are not copied, and neither is the machine's own name inside: if you are going to have both running on the network, change it from within the clone's system.

Taking it to another NAS

Under Details, with the machine powered off, "Take it away" leaves it in a single file (.lgmvm) inside the household folder you choose, to copy it to another NAS or keep it. On the other machine, "Bring a machine" —at the top, next to "New machine"— asks which folder you left it in, which of the ones there, and what it will be called, and sets it up.

• The system disk travels. If the machine has data disks, take them off first (or copy them separately from Files).
• It arrives powered off, not starting with the NAS and with a new network card: it will ask for its own address when you switch it on.
• Whatever its TPM chip held does not travel: if BitLocker was enabled inside, Windows will ask for the recovery key the first time it starts.
• **A package exported by a NAS that has not been updated does not say how the machine booted**, so it is set up as a new one: BIOS, with the fast disk and network (VirtIO). If there is a Windows inside or it booted through UEFI, it will not start: export it again from an updated NAS and bring it over again. The "imported" alert says so when this happens.

Snapshots

Before a delicate change —a system update inside, touching a Windows registry—, "New snapshot". If it goes wrong, "Go back here" and the machine is as it was.

• With the machine running, the snapshot also saves the memory: on going back, it appears exactly as it was, programs open. It takes a while (it is copying the RAM).
• With the machine off, it is disk only and immediate.

⚠️ A snapshot is not a backup: it lives in the same file and on the same disk as the machine. If the volume is lost, they are lost together. That is what backups are for: a backup job can carry your machines —the disk and its definition, so they start again when restored—, running ones too, which are copied from a snapshot.

Windows, with its three conditions

• Windows 11 demands UEFI, secure boot and TPM 2.0 before it lets itself be installed. All three are switches under "advanced hardware" — turn them on before installing. Changing the firmware of an already installed machine leaves it unable to boot: a system installed under BIOS does not boot through UEFI, nor the other way round.
• The machines' disk and network are VirtIO (the fast ones). Linux ships with them; the Windows installer does not carry the disk driver and will not see anywhere to install: use a Windows ISO with the VirtIO drivers built in (search "virtio-win" plus your version; preparing it takes ten minutes and is done once).
• Once the system is installed, add the guest agent (on Linux, the qemu-guest-agent package; on Windows it comes with the VirtIO drivers): with it the panel sees the IP and orderly shutdown always works.

When it pauses itself

If the storage underneath cannot write, qemu pauses the machine rather than let it corrupt itself. The panel does not stop at "it is paused": it investigates, and the notice tells you which of the four cases it is, because only one is fixed by deleting:

1. Plenty of room → it is not space: volume metadata or a damaged image.
2. The volume claims gigabytes and still refuses writes → clogged volume: fixed with Storage's "Rebalance" button, not by deleting.
3. The folder cannot grow but the volume can → there is a quota on that folder.
4. Truly full → free up space.

With the cause fixed, the "Resume" button wakes it up where it was.

Deleting a machine

"Delete" removes the machine and its disk —its data disks too— with everything inside, and there is no way back. A data disk that lived outside the machine's folder is left where it was, and the notice says which one; if <pool>/vm/<name>/ holds files that are not its own, the panel leaves the folder and tells you.

The machine also leaves the backups that carried it. A backup job that only saved that machine is switched off, and what it already copied stays at its destination.