Hope this email finds you well.
I have been trying with qemu for a while now, and have come across a problem specific to dirty bitmaps. I have enabled bitmap on the qcow2 disk image using 'qemu-img bitmap' command, exposed the bitmap over a unix socket using 'qemu-nbd' command. Now when I try to read the bitmap using 'qemu-img map' command with 'x-dirty-bitmap=qemu:dirty-bitmap:{bitmap}' option, I get one single extent which shows that the entire disk is dirty. Note that the disk size is 5 GB, and has only a few MB of data in it, and had added very small data after the bitmap was enabled. Bitmap output has been pasted below.
[{ "start": 0, "length": 5368709120, "depth": 0, "present": true, "zero": false, "data": true, "compressed": false, "offset": 0}]
Can someone please help me understand why the bitmap content shows the entire disk as dirty?
Regards
Prashant