1QA output created by 114 2qemu-img: warning: Deprecated use of backing file without explicit backing format (detected format of raw) 3Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=67108864 backing_file=TEST_DIR/t.IMGFMT.orig 4Formatting 'TEST_DIR/t.IMGFMT.base', fmt=IMGFMT size=67108864 5qemu-img: warning: Deprecated use of backing file without explicit backing format 6qemu-img: warning: Deprecated use of backing file without explicit backing format (detected format of IMGFMT) 7Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=67108864 backing_file=TEST_DIR/t.IMGFMT.base backing_fmt=IMGFMT 8qemu-img: warning: Deprecated use of unopened backing file without explicit backing format, use of this image requires potentially unsafe format probing 9Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=67108864 backing_file=TEST_DIR/t.IMGFMT.base 10image: TEST_DIR/t.IMGFMT 11file format: IMGFMT 12virtual size: 64 MiB (67108864 bytes) 13cluster_size: 65536 14backing file: TEST_DIR/t.IMGFMT.base 15backing file format: foo 16qemu-io: can't open device TEST_DIR/t.qcow2: Could not open backing file: Unknown driver 'foo' 17no file open, try 'help open' 18read 4096/4096 bytes at offset 0 194 KiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec) 20qemu-img: warning: Deprecated use of backing file without explicit backing format, use of this image requires potentially unsafe format probing 21read 4096/4096 bytes at offset 0 224 KiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec) 23*** done 24