devel/testing/blkverify.rst

5 ------------
7 This document describes how to use the ``blkverify`` protocol to test that a block
10 It is difficult to test and debug block drivers against real guests.  Often
11 processes inside the guest will crash because corrupt sectors were read as part
20 ------------
22 The ``blkverify`` protocol has two child block devices, the "test" device and the
27 contents to the "test" image.  The idea is that the "raw" device will handle
29 reference for comparison against the "test" device.
36 -------
40     $ ./qemu-io -c 'read -v 0 512' raw.img
49 And test.img is corrupt, its first sector is zeroed when it shouldn't be::
51     $ ./qemu-io -c 'read -v 0 512' test.img
62     $ ./qemu-io -c 'read 0 512' blkverify:a.img:b.img
67     $ ./qemu-img create raw.img 16G
68     $ ./qemu-img create -f qcow2 test.qcow2 16G
69     $ ./qemu-system-x86_64 -cdrom debian.iso \
70           -drive file=blkverify:raw.img:test.qcow2
72 If the installation is aborted when ``blkverify`` detects corruption, use ``qemu-io``