How to convert multiple raw images to qcow2?

I have created 1 VM in qemu using 2 raw images, which has 2 partitions as
given below.

/dev/sda1 910G 263G 601G 31% /
/dev/sdb 5G 1G 4G 20% /mnt

Then I am stopping the VM and converting both raw images to qcow2 format.
Using these qcow2 images I am trying to launch a new vm. But vm is not
loading properly, its going in rescue mode. Is it possible to convert
multiple raw to qcow2 images?