How can I increase size of live-disk partition? It is always 4 gigs. I cannot run VMs in live mode due to a lack of space on live disk. I have tried various methods, but nothing has worked. Please help
Does it help to increase RAM?
Or set the VMs up while in persistent mode, then boot into live mode and start using the VMs?
Otherwise you might need to check with upstream. See grub-live, Simplified Summary.
Please post here should you find a solution for that.
Increase in RAM only. Swap doesnt help. I will buy a new laptop 
To work with VMs, you need to have at least 20 gb RAM, but 32 gb is better. But this means that live mode is very safe and similar to Tails. You can write on site that VMs will require a lot of memory in live mode if someone wants to work with VMs. Thank you. I really like Kicksecure