I’m having the exact same problem. The /var/log/libvirt/libxl/libxl-driver.log file in dom0 has the same output as in the following thread:
xc_dom_boot_mem_init: can't allocate low memory for domain: Out of memory
libxl-driver.log (2.9 KB)
I tried restarting libvirtd ( systemctl restart libvirtd ) as suggested but the error keeps occurring.
I assume that libvirt is not managing to reallocate the memory from running qubes to start the new one. I’m using few applications (firefox w/ 3 tabs, thunderbird and audio player) in only two qubes and have 32 GB RAM, so it’d seem that memory is not a problem. In my case, stopping the qube with the audio player allowed me to start the new qube (its minimum memory is at 1700 MB).
Is there some tool that allows one to see how memory is being allocated between dom0 and the other qubes to figure out where what I thought was more memory than I could ever use is disappearing to?
I usually click on the Qubes Manager icon in the sys-tray and the memory used by each qube is shown. However as I understand, the memory allocated to each qube is not exactly the total memory used by the processes – the available memory is distributed among qubes according to their needs. But I don’t know how to check the actual memory being used for the processes to calculate total free memory.