```bash
# Stop & backup
xm shutdown sandbox
cp -a sandbox/ sandbox.bk
# Verify MD5 sum
md5sum sandbox/disk.img
4976347006df34843d29c939b5fc3742 sandbox/disk.img
md5sum sandbox.bk/disk.img
4976347006df34843d29c939b5fc3742 sandbox.bk/disk.img
# Create a 5Gb temp file
dd if=/dev/zero of=Tempfile bs=1024 count=5000000
# Append it to the existing image
cat Tempfile >> disk.img
rm Tempfile
# Resize the partition
resize2fs -f disk.img
# Check partition & start domU
fsck.ext3 disk.img
xm create -c sandbox.cfg
```