On Mon, 14 Feb 2022 10:54:22 +0530 (IST) Ani Sinha <a...@anisinha.ca> wrote:
> Hi Igor: > > I failed to spawn a 9 Tib VM. The max I could do was a 2 TiB vm on my > system with the following commandline before either the system > destabilized or the OOM killed killed qemu > > -m 2T,maxmem=9T,slots=1 \ > -object > memory-backend-file,id=mem0,size=2T,mem-path=/data/temp/memfile,prealloc=off \ > -machine memory-backend=mem0 \ > -chardev file,path=/tmp/debugcon2.txt,id=debugcon \ > -device isa-debugcon,iobase=0x402,chardev=debugcon \ > > I have attached the debugcon output from 2 TiB vm. > Is there any other commandline parameters or options I should try? > > thanks > ani $ truncate -s 9T 9tb_sparse_disk.img $ qemu-system-x86_64 -m 9T \ -object memory-backend-file,id=mem0,size=9T,mem-path=9tb_sparse_disk.img,prealloc=off,share=on \ -machine memory-backend=mem0 works for me till GRUB menu, with sufficient guest kernel persuasion (i.e. CLI limit ram size to something reasonable) you can boot linux guest on it and inspect SMBIOS tables comfortably. With KVM enabled it bails out with: qemu-system-x86_64: kvm_set_user_memory_region: KVM_SET_USER_MEMORY_REGION failed, slot=1, start=0x100000000, size=0x8ff40000000: Invalid argument all of that on a host with 32G of RAM/no swap.
