How to create 256GB zns ssd

[OGSD]

I create 512G disk image
qemu-img create -f qcow2 femu.qcow2 512G

I modify run-zns.sh
devsz_mb=262144

when i run run-zns.sh
i got the error this error
qemu-system-x86_64: -device femu,devsz_mb=262144,femu_mode=3: GLib: ../../../glib/gmem.c:167: failed to allocate 274877906944 bytes

how can i solve it

[inhoinno]

How much memory do you have in the Host machine?
In FEMU, the device memory should be larger than the device size(256GB)