- run this in terminal of virtual bigSur but change bs (blocksize in bits) and count (anzahl der zu schreibenden blöcke) to specify the amount of free space you want to Release
dd if=/dev/zero of=file.of.zeros bs=67108864 count=1250
- shutdown the vm
- run this in comand promt
VBoxManage modifymedium --compact "path\to\bigSur.vdi"
(4. optional leave files.of.zero to prevent bigsur to reclaim the space)
This comment was very helpful for me.
"C:\Program Files\Oracle\VirtualBox\VBoxManage.exe" setextradata "android" "CustomVideoMode1" "360x640x32"
e (in boot menue)
e (to edit boot cmd)
vga=ask (append)
ESC
b (to boot)
ENTER (to view res options)
remeber hex video moode value (here 360)
debug mode
mount -o remount,rw /mnt
cd /mnt/grub
vi menu.lst
i (insert mode)
vga=(deciaml video mode value here 864)
ESC (exit insert mode)
:w (write)
:x (exit)
reboot -f