How to solve the disk space exceeds problem

I used Kaniko in cloud environment and the root execution environment / only supports 10GB. The base image of dockerfile is almost 30GB. When image building, Kaniko will unpacking rootfs, and the disk size exceeds. I mount a volume to /mnt/dir, how to unpacking rootfs to /mnt/dir, or any other solutions? The sample docker file is as follow.

FROM qwen:latest
ADD ./test /