grub2 error disk 'hd0,msdos1' not found, ls shows no disk

I have googled a lot for this problem. I found this, but it didn't solve my problem. Other solutions suggest me to reinstall grub (run grub-install), which didn't work either. Here is what I am doing: (my grub version is 2.02) 1. I use grub2-mkrescue to make my X.iso 2. I boot a VMWareWorkstation virtual machine, which has a 1.0GB SATA disk, from X.iso 3. I install X.iso on disk, the details are: 3.1. erase /dev/sda in case there are old partitions on it: dd if=/dev/zero of=/dev/sda bs=1M count=1 3.2. Create 3 primary partitions on /dev/sda as dev/sda1,sda2,sda3 (the size is 100M, 30M and 70M), and toggle sda1 to be bootable

Disk /dev/sda: 1024 MB, 1073741824 bytes, 2097152 sectors
130 cylinders, 255 heads, 63 sectors/track
Units: sectors of 1 * 512 = 512 bytes

Device  Boot StartCHS    EndCHS        StartLBA     EndLBA    Sectors  Size Id Type
/dev/sda1 *  0,1,1       12,191,50           63     204862     204800  100M 83 Linux
/dev/sda2    12,191,51   16,147,2        204863     266302      61440 30.0M 83 Linux
/dev/sda3    16,147,3    25,127,37       266303     409662     143360 70.0M 83 Linux

3.3. Format the 3 partitions as ext2, and mount /dev/sda1

mkfs.ext2 /dev/sda1
mkfs.ext2 /dev/sda2
mkfs.ext2 /dev/sda3
ROOTFS_PATH=/var/.rootfs
mkdir $ROOTFS_PATH
mount /dev/sda1 $ROOTFS_PATH

3.4 copy files...

for i in bzImage initrd.img vmlinuz-*; do
    cp -rf /boot/$i $ROOTFS_PATH/boot
done
cp -f /boot/grub/device.map $ROOTFS_PATH/boot/grub/device.map
for i in init linuxrc; do
    cp -rf /$i $ROOTFS_PATH
done
for i in bin etc lib sbin share usr; do
    cp -a /$i $ROOTFS_PATH
done
for i in dev var proc sys tmp data log; do
    mkdir -p $ROOTFS_PATH/$i
done

3.5 Install grub and make grub config file

chroot $ROOTFS_PATH

And the most strange thing is that ls command shows nothing in grub-rescue cli ---- as someone says, it should show disk list.