Officially, Qubes requires 6 GB of memory, as per https://doc.qubes-os.org/en/latest/user/hardware/system-requirements.html#minimum
I have the required x86_64 processor and storage space, but my laptop has 4 GB of RAM.
It seemed to be working fine without OOM errors, and it is idling well below 2 GB (I don’t remember the exact amount) RAM usage. I’m not doing much with Qubes, right now I’m just messing around with it on an SD card and getting a feel for it. My actually powerful laptop is broken right now and the manufacturer’s customer support is being… difficult.
My point being, how usable is Qubes with only 4 GB RAM for extremely light stuff?
Unusable even with minimum of 6GB, even 8GB will offer you bad experience.
You can use QubesOS in devices with DDR3 for first impression, just find over 8GB RAM and intel 4th gen,
Actually usable, but need a lots of modifies. Like using mirage firewall, combine sys-net and sys-usb into one qube, disable guivm and audiovm for some qube. Some security on security are necessary when you only have 8g ram. But 4G are truly unusable even if you sacrifice some security.
I’m going out on a limb based on my experience.
4G is just about usable with considerable modifications, reduced
security, reduced expectations on what you can do, and patience.
Another 4GB would be very usable, at quite small cost, if you
can manage that. If not, try what you can:
Reduce the amount memory set aside for dom0.
Use mirage firewall.
Use minimal templates where you can.
Reduce memory allocated to your qubes as low as it can go.
Drop Whonix.
I never presume to speak for the Qubes team.
When I comment in the Forum I speak for myself.
The work around is to close as many VMs as possible before starting such driver domain, and then also reducing, for a moment, the amount of memory assigned to Dom0:
[dom0]$ xm mem-set 0 1600m
and then starting the driver domain should be fine. Now we can start all other domains, and that should no longer be problematic for the already running driver domain.
However, my current Qubes OS setup is ultra-lightweight no lite qube at all. I use the official Qubes OS but minimize it extensively for security. With this setup, you can run all main system VMs (except sys-whonix ). You can install WireGuard directly in sys-net . There’s no separate sys-dns , as it’s not feasible with 4 GB RAM. You can safely run one dedicated AppVM or DispVM for browsing, YouTube, or similar tasks but only one at a time.