To run xfstest on overlayfs, configure the variables of TEST and SCRATCH partitions to be used as the "base fs" and run './check -overlay'. For example, the following config file can be used to run tests on xfs test/scratch partitions: TEST_DEV=/dev/sda5 TEST_DIR=/mnt/test SCRATCH_DEV=/dev/sda6 SCRATCH_MNT=/mnt/scratch FSTYP=xfs Using the same config file, but executing './check -overlay' will use the same partitions as base fs for overlayfs directories and set TEST_DIR/SCRATCH_MNT values to overlay mount points, i.e.: /mnt/test/ovl-mnt and /mnt/scratch/ovl-mnt, for the context of individual tests.