Rooting android emulator - Error?

I have to root android emulator. I've found some articles, but I've got the same error every time! It's 'cannot create su: not enough memory'! What I did:

1. adb push su /data/local
2. adb shell 
3. #su
4. #mount -o remount,rw -t yaffs2 /dev/block/mtdblock3 /system
5. # cd /system/xbin
6. # mv su osu
7. # cat /data/local/su > su // I've got an error!!! 
//Cannot create su: Out 开发者_开发百科of memory!

What do I wrong?

I've got answer on my question! I must run an android emulator with -partition-size 128 option. It should look like below:

android-sdk-windows\tools\emulator -avd MyAndroidVirtualDeviceName -partition-size 128 

After that I can root my emulator.

Looks like /system/xbin is not rw. The fact that mount -o remount,rw does not return errors doesn't mean that it succeeded. Check what mount reports for /system after the remount. Also, see if you have proper permissions to write there.