I wanna run an android emulator with disk images

Question

hi i'd like to run an android emulator with disk image. so I tried this

./emulator -kernel kernel-qemu -system system.img -ramdisk ramdisk.img -initdata userdata.img -partition-size 512

then error massage is :

if you really want to NOT run an AVD, consider using '-data ' to specify a data partition image file (I hope you know what you're doing).

so I tried to find userdata-qemu.img from /out/ but i can't find that file. someone help me