virtualbox.org

I want to create a VM which has about 10 GiB ram, but there are only 8 GiB on my host machines

Have any way to allowcate Swap memory or HDD to use like ram for guest machine?

Thank!
Best regard!

Not that I know of. The RAM has to be real, existing and available. Can you give 12 GB to your host? Not that I know of.