I've tried to use backbox on a flash drive by using Grub. But it won't boot. It gives an error "unable to find '/dev/zram0'

Here's my grub menuentry:

menuentry "Backbox" {
 set isofile="/backbox.iso"
 loopback loop $isofile
 linux (loop)/casper/vmlinuz boot=casper isoloop=/filename=$isofile noprompt noeject
 initrd (loop)/casper/initrd.gz
}
Can anyone tell me what i did wrong ?

Great,

Thanks for share !