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Please provide a testing procedure/notes so QE can verify this functionality is implemented correctly when the patches are applied.

thanks,
Martin

The best way to verify is probably to take a VM with two disks (one system disk and one empty test disk; the test disk being in raw format) and with a QMP server enabled. Connect to the QMP server (e.g. using netcat) and issue a query-blockstats command. With the connection setup this might look like this:

{"QMP": {"version": {"qemu": "0.12.1", "package": " (qemu-kvm-devel)"}, "capabilities": []}}
{ "execute": "qmp_capabilities" }
{"return": {}}
{ "execute": "query-blockstats" }
{"return": [{"device": "ide0-hd0", "parent": {"stats": {"wr_highest_offset": 0, "wr_bytes": 0, "wr_operations": 0, "rd_bytes": 45067264, "rd_operations": 14679}}, "stats": {"wr_highest_offset": 0, "wr_bytes": 0, "wr_operations": 0, "rd_bytes": 45647360, "rd_operations": 15452}}, {"device": "ide0-hd1", "parent": {"stats": {"wr_highest_offset": 0, "wr_bytes": 0, "wr_operations": 0, "rd_bytes": 430080, "rd_operations": 73}}, "stats": {"wr_highest_offset": 0, "wr_bytes": 0, "wr_operations": 0, "rd_bytes": 430080, "rd_operations": 73}}, {"device": "ide1-cd0", "stats": {"wr_highest_offset": 0, "wr_bytes": 0, "wr_operations": 0, "rd_bytes": 0, "rd_operations": 0}}, {"device": "floppy0", "stats": {"wr_highest_offset": 0, "wr_bytes": 0, "wr_operations": 0, "rd_bytes": 0, "rd_operations": 0}}, {"device": "sd0", "stats": {"wr_highest_offset": 0, "wr_bytes": 0, "wr_operations": 0, "rd_bytes": 0, "rd_operations": 0}}]}

Make sure that both disks are present and that their parent has a wr_highest_offset value (this is the watermark). Now try writing to different offsets in the test disk (e.g. using dd) and repeatedly issue more query-blockstats commands to check if the watermark is correctly changed to reflect the start of the highest sector that you have written to.

Test this issue according to Comment 5, using qemu-kvm-0.12.1.2-2.68.el6.

Paste my result here:(only paste the test disk info)
1. Boot a guest with two disk, one is system disk, another is a raw empty disk with 5G size.

"device": "ide0-hd1", "parent": {"stats": {"wr_highest_offset": 0, "wr_bytes": 0, "wr_operations": 0, "rd_bytes": 655872, "rd_operations": 65}}, "stats": {"wr_highest_offset": 0, "wr_bytes": 0, "wr_operations": 0, "rd_bytes": 655872, "rd_operations": 65}},

2.write some data in the test disk.
dd if=/dev/zero of=/dev/hdb bs=1M count=100

"device": "ide0-hd1", "parent": {"stats": {"wr_highest_offset": 104857088, "wr_bytes": 104857600, "wr_operations": 201, "rd_bytes": 725504, "rd_operations": 69}}, "stats": {"wr_highest_offset": 104857088, "wr_bytes": 104857600, "wr_operations": 201, "rd_bytes": 725504, "rd_operations": 69}},

3.dd if=/dev/zero of=/dev/hdb seek=100 bs=1M count=100

"device": "ide0-hd1", "parent": {"stats": {"wr_highest_offset": 209714688, "wr_bytes": 209715200, "wr_operations": 402, "rd_bytes": 725504, "rd_operations": 69}}, "stats": {"wr_highest_offset": 209714688, "wr_bytes": 209715200, "wr_operations": 402, "rd_bytes": 725504, "rd_operations": 69}},

4.dd if=/dev/zero of=/dev/hdb seek=1024 bs=1M count=100

"device": "ide0-hd1", "parent": {"stats": {"wr_highest_offset": 1178598912, "wr_bytes": 419430400, "wr_operations": 804, "rd_bytes": 725504, "rd_operations": 69}}, "stats": {"wr_highest_offset": 1178598912, "wr_bytes": 419430400, "wr_operations": 804, "rd_bytes": 725504, "rd_operations": 69}},

5. dd if=/dev/zero of=/dev/hdb seek=700 bs=1M count=100

"device": "ide0-hd1", "parent": {"stats": {"wr_highest_offset": 1178598912, "wr_bytes": 524288000, "wr_operations": 1005, "rd_bytes": 725504, "rd_operations": 69}}, "stats": {"wr_highest_offset": 1178598912, "wr_bytes": 524288000, "wr_operations": 1005, "rd_bytes": 725504, "rd_operations": 69}},

6.Write data to the offset outside the disk
dd if=/dev/zero of=/dev/hdb seek=6000 bs=1M count=100
dd:writing to '/dev/hdb':No space left on device

"device": "ide0-hd1", "parent": {"stats": {"wr_highest_offset": 1178598912, "wr_bytes": 524288000, "wr_operations": 1005, "rd_bytes": 5369434624, "rd_operations": 20630}}, "stats": {"wr_highest_offset": 1178598912, "wr_bytes": 524288000, "wr_operations": 1005, "rd_bytes": 5369434624, "rd_operations": 20630}},


qzhang -> Kevin
Could I call this verified pass? BTW, what does "parent" mean?  thanks!

Yes, the results look good to me and cover everything I suggested.

"parent" means the underlying protocol that is used to access the qcow2 data, e.g. file or host_device (or even nbd or http, but I don't think we support these with RHEL).

(In reply to comment #10)
> Yes, the results look good to me and cover everything I suggested.
> 
> "parent" means the underlying protocol that is used to access the qcow2 data,
> e.g. file or host_device (or even nbd or http, but I don't think we support
> these with RHEL).    

Thank you Kevin, then I will close this issue. :)

*** Bug 547628 has been marked as a duplicate of this bug. ***