Re: [PATCH 2/3] iotests: Test qemu-img checksum

[Nir Soffer]

On Mon, Nov 7, 2022 at 1:41 PM Hanna Reitz  wrote:

> On 30.10.22 18:38, Nir Soffer wrote:
> > On Wed, Oct 26, 2022 at 4:31 PM Hanna Reitz  wrote:
> >
> > On 01.09.22 16:32, Nir Soffer wrote:
> > > Add simple tests creating an image with all kinds of extents,
> > different
> > > formats, different backing chain, different protocol, and different
> > > image options. Since all images have the same guest visible
> > content they
> > > must have the same checksum.
> > >
> > > To help debugging in case of failures, the output includes a
> > json map of
> > > every test image.
> > >
> > > Signed-off-by: Nir Soffer 
> > > ---
> > >   tests/qemu-iotests/tests/qemu-img-checksum| 149
> > ++
> > >   .../qemu-iotests/tests/qemu-img-checksum.out  |  74 +
> > >   2 files changed, 223 insertions(+)
> > >   create mode 100755 tests/qemu-iotests/tests/qemu-img-checksum
> > >   create mode 100644 tests/qemu-iotests/tests/qemu-img-checksum.out
> > >
> > > diff --git a/tests/qemu-iotests/tests/qemu-img-checksum
> > b/tests/qemu-iotests/tests/qemu-img-checksum
> > > new file mode 100755
> > > index 00..3a85ba33f2
> > > --- /dev/null
> > > +++ b/tests/qemu-iotests/tests/qemu-img-checksum
> > > @@ -0,0 +1,149 @@
> > > +#!/usr/bin/env python3
> > > +# group: rw auto quick
> > > +#
> > > +# Test cases for qemu-img checksum.
> > > +#
> > > +# Copyright (C) 2022 Red Hat, Inc.
> > > +#
> > > +# This program is free software; you can redistribute it and/or
> > modify
> > > +# it under the terms of the GNU General Public License as
> > published by
> > > +# the Free Software Foundation; either version 2 of the License,
> or
> > > +# (at your option) any later version.
> > > +#
> > > +# This program is distributed in the hope that it will be useful,
> > > +# but WITHOUT ANY WARRANTY; without even the implied warranty of
> > > +# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
> > > +# GNU General Public License for more details.
> > > +#
> > > +# You should have received a copy of the GNU General Public
> License
> > > +# along with this program.  If not, see
> > .
> > > +
> > > +import re
> > > +
> > > +import iotests
> > > +
> > > +from iotests import (
> > > +filter_testfiles,
> > > +qemu_img,
> > > +qemu_img_log,
> > > +qemu_io,
> > > +qemu_nbd_popen,
> > > +)
> > > +
> > > +
> > > +def checksum_available():
> > > +out = qemu_img("--help").stdout
> > > +return re.search(r"\bchecksum .+ filename\b", out) is not None
> > > +
> > > +
> > > +if not checksum_available():
> > > +iotests.notrun("checksum command not available")
> > > +
> > > +iotests.script_initialize(
> > > +supported_fmts=["raw", "qcow2"],
> > > +supported_cache_modes=["none", "writeback"],
> >
> > It doesn’t work with writeback, though, because it uses -T none
> below.
> >
> >
> > Good point
> >
> >
> > Which by the way is a heavy cost, because I usually run tests in
> > tmpfs,
> > where this won’t work.  Is there any way of not doing the -T none
> > below?
> >
> >
> > Testing using tempfs is problematic since you cannot test -T none.In
> > oVirt
> > we alway use /var/tmp which usually uses something that supports
> > direct I/O.
> >
> > Do we have a way to specify cache mode in the tests, so we can use -T
> none
> > only when the option is set?
>
> `./check` has a `-c` option (e.g. `./check -c none`), which lands in
> `iotests.cachemode`.  That isn’t automatically passed to qemu-img calls,
> but you can do it manually (i.e. `qemu_img_log("checksum", "-T",
> iotests.cachemode, disk_top)` instead of `"-T", "none"`).
>

Ok, I will change to use the current cache setting.


> >
> > > +supported_protocols=["file", "nbd"],
> > > +required_fmts=["raw", "qcow2"],
> > > +)
> > > +
> > > +print()
> > > +print("=== Test images ===")
> > > +print()
> > > +
> > > +disk_raw = iotests.file_path('raw')
> > > +qemu_img("create", "-f", "raw", disk_raw, "10m")
> > > +qemu_io("-f", "raw",
> > > +"-c", "write -P 0x1 0 2m",  # data
> > > +"-c", "write -P 0x0 2m 2m", # data with zeroes
> > > +"-c", "write -z 4m 2m", # zero allocated
> > > +"-c", "write -z -u 6m 2m",  # zero hole
> > > +# unallocated
> > > +disk_raw)
> > > +print(filter_testfiles(disk_raw))
> > > +qemu_img_log("map", "--output", "json", disk_raw)
> > > +
> > > +disk_qcow2 = iotests.file_path('qcow2')
> > > +qemu_img("create", "-f", "qcow2", disk_qcow2, "10m")
> > > +qemu_io("-f", "qcow2",
> > 

Re: [PATCH 2/3] iotests: Test qemu-img checksum

[Hanna Reitz]

On 30.10.22 18:38, Nir Soffer wrote:

On Wed, Oct 26, 2022 at 4:31 PM Hanna Reitz  wrote:

On 01.09.22 16:32, Nir Soffer wrote:
> Add simple tests creating an image with all kinds of extents,
different
> formats, different backing chain, different protocol, and different
> image options. Since all images have the same guest visible
content they
> must have the same checksum.
>
> To help debugging in case of failures, the output includes a
json map of
> every test image.
>
> Signed-off-by: Nir Soffer 
> ---
>   tests/qemu-iotests/tests/qemu-img-checksum    | 149
++
>   .../qemu-iotests/tests/qemu-img-checksum.out  |  74 +
>   2 files changed, 223 insertions(+)
>   create mode 100755 tests/qemu-iotests/tests/qemu-img-checksum
>   create mode 100644 tests/qemu-iotests/tests/qemu-img-checksum.out
>
> diff --git a/tests/qemu-iotests/tests/qemu-img-checksum
b/tests/qemu-iotests/tests/qemu-img-checksum
> new file mode 100755
> index 00..3a85ba33f2
> --- /dev/null
> +++ b/tests/qemu-iotests/tests/qemu-img-checksum
> @@ -0,0 +1,149 @@
> +#!/usr/bin/env python3
> +# group: rw auto quick
> +#
> +# Test cases for qemu-img checksum.
> +#
> +# Copyright (C) 2022 Red Hat, Inc.
> +#
> +# This program is free software; you can redistribute it and/or
modify
> +# it under the terms of the GNU General Public License as
published by
> +# the Free Software Foundation; either version 2 of the License, or
> +# (at your option) any later version.
> +#
> +# This program is distributed in the hope that it will be useful,
> +# but WITHOUT ANY WARRANTY; without even the implied warranty of
> +# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
> +# GNU General Public License for more details.
> +#
> +# You should have received a copy of the GNU General Public License
> +# along with this program.  If not, see
.
> +
> +import re
> +
> +import iotests
> +
> +from iotests import (
> +    filter_testfiles,
> +    qemu_img,
> +    qemu_img_log,
> +    qemu_io,
> +    qemu_nbd_popen,
> +)
> +
> +
> +def checksum_available():
> +    out = qemu_img("--help").stdout
> +    return re.search(r"\bchecksum .+ filename\b", out) is not None
> +
> +
> +if not checksum_available():
> +    iotests.notrun("checksum command not available")
> +
> +iotests.script_initialize(
> +    supported_fmts=["raw", "qcow2"],
> +    supported_cache_modes=["none", "writeback"],

It doesn’t work with writeback, though, because it uses -T none below.


Good point


Which by the way is a heavy cost, because I usually run tests in
tmpfs,
where this won’t work.  Is there any way of not doing the -T none
below?


Testing using tempfs is problematic since you cannot test -T none.In 
oVirt
we alway use /var/tmp which usually uses something that supports 
direct I/O.


Do we have a way to specify cache mode in the tests, so we can use -T none
only when the option is set?


`./check` has a `-c` option (e.g. `./check -c none`), which lands in 
`iotests.cachemode`.  That isn’t automatically passed to qemu-img calls, 
but you can do it manually (i.e. `qemu_img_log("checksum", "-T", 
iotests.cachemode, disk_top)` instead of `"-T", "none"`).




> +    supported_protocols=["file", "nbd"],
> +    required_fmts=["raw", "qcow2"],
> +)
> +
> +print()
> +print("=== Test images ===")
> +print()
> +
> +disk_raw = iotests.file_path('raw')
> +qemu_img("create", "-f", "raw", disk_raw, "10m")
> +qemu_io("-f", "raw",
> +        "-c", "write -P 0x1 0 2m",      # data
> +        "-c", "write -P 0x0 2m 2m",     # data with zeroes
> +        "-c", "write -z 4m 2m",         # zero allocated
> +        "-c", "write -z -u 6m 2m",      # zero hole
> +                                        # unallocated
> +        disk_raw)
> +print(filter_testfiles(disk_raw))
> +qemu_img_log("map", "--output", "json", disk_raw)
> +
> +disk_qcow2 = iotests.file_path('qcow2')
> +qemu_img("create", "-f", "qcow2", disk_qcow2, "10m")
> +qemu_io("-f", "qcow2",
> +        "-c", "write -P 0x1 0 2m",      # data
> +        "-c", "write -P 0x0 2m 2m",     # data with zeroes
> +        "-c", "write -z 4m 2m",         # zero allocated
> +        "-c", "write -z -u 6m 2m",      # zero hole
> +                                        # unallocated
> +        disk_qcow2)
> +print(filter_testfiles(disk_qcow2))
> +qemu_img_log("map", "--output", "json", disk_qcow2)

This isn’t how iotests work, generally.  When run with -qcow2
-file, it
should only test qcow2 on file, not raw on file, not raw on nbd.
Perhaps
   

Re: [PATCH 2/3] iotests: Test qemu-img checksum

[Nir Soffer]

On Wed, Oct 26, 2022 at 4:31 PM Hanna Reitz  wrote:

> On 01.09.22 16:32, Nir Soffer wrote:
> > Add simple tests creating an image with all kinds of extents, different
> > formats, different backing chain, different protocol, and different
> > image options. Since all images have the same guest visible content they
> > must have the same checksum.
> >
> > To help debugging in case of failures, the output includes a json map of
> > every test image.
> >
> > Signed-off-by: Nir Soffer 
> > ---
> >   tests/qemu-iotests/tests/qemu-img-checksum| 149 ++
> >   .../qemu-iotests/tests/qemu-img-checksum.out  |  74 +
> >   2 files changed, 223 insertions(+)
> >   create mode 100755 tests/qemu-iotests/tests/qemu-img-checksum
> >   create mode 100644 tests/qemu-iotests/tests/qemu-img-checksum.out
> >
> > diff --git a/tests/qemu-iotests/tests/qemu-img-checksum
> b/tests/qemu-iotests/tests/qemu-img-checksum
> > new file mode 100755
> > index 00..3a85ba33f2
> > --- /dev/null
> > +++ b/tests/qemu-iotests/tests/qemu-img-checksum
> > @@ -0,0 +1,149 @@
> > +#!/usr/bin/env python3
> > +# group: rw auto quick
> > +#
> > +# Test cases for qemu-img checksum.
> > +#
> > +# Copyright (C) 2022 Red Hat, Inc.
> > +#
> > +# This program is free software; you can redistribute it and/or modify
> > +# it under the terms of the GNU General Public License as published by
> > +# the Free Software Foundation; either version 2 of the License, or
> > +# (at your option) any later version.
> > +#
> > +# This program is distributed in the hope that it will be useful,
> > +# but WITHOUT ANY WARRANTY; without even the implied warranty of
> > +# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
> > +# GNU General Public License for more details.
> > +#
> > +# You should have received a copy of the GNU General Public License
> > +# along with this program.  If not, see .
> > +
> > +import re
> > +
> > +import iotests
> > +
> > +from iotests import (
> > +filter_testfiles,
> > +qemu_img,
> > +qemu_img_log,
> > +qemu_io,
> > +qemu_nbd_popen,
> > +)
> > +
> > +
> > +def checksum_available():
> > +out = qemu_img("--help").stdout
> > +return re.search(r"\bchecksum .+ filename\b", out) is not None
> > +
> > +
> > +if not checksum_available():
> > +iotests.notrun("checksum command not available")
> > +
> > +iotests.script_initialize(
> > +supported_fmts=["raw", "qcow2"],
> > +supported_cache_modes=["none", "writeback"],
>
> It doesn’t work with writeback, though, because it uses -T none below.
>

Good point


>
> Which by the way is a heavy cost, because I usually run tests in tmpfs,
> where this won’t work.  Is there any way of not doing the -T none below?
>

Testing using tempfs is problematic since you cannot test -T none. In oVirt
we alway use /var/tmp which usually uses something that supports direct I/O.

Do we have a way to specify cache mode in the tests, so we can use -T none
only when the option is set?


>
> > +supported_protocols=["file", "nbd"],
> > +required_fmts=["raw", "qcow2"],
> > +)
> > +
> > +print()
> > +print("=== Test images ===")
> > +print()
> > +
> > +disk_raw = iotests.file_path('raw')
> > +qemu_img("create", "-f", "raw", disk_raw, "10m")
> > +qemu_io("-f", "raw",
> > +"-c", "write -P 0x1 0 2m",  # data
> > +"-c", "write -P 0x0 2m 2m", # data with zeroes
> > +"-c", "write -z 4m 2m", # zero allocated
> > +"-c", "write -z -u 6m 2m",  # zero hole
> > +# unallocated
> > +disk_raw)
> > +print(filter_testfiles(disk_raw))
> > +qemu_img_log("map", "--output", "json", disk_raw)
> > +
> > +disk_qcow2 = iotests.file_path('qcow2')
> > +qemu_img("create", "-f", "qcow2", disk_qcow2, "10m")
> > +qemu_io("-f", "qcow2",
> > +"-c", "write -P 0x1 0 2m",  # data
> > +"-c", "write -P 0x0 2m 2m", # data with zeroes
> > +"-c", "write -z 4m 2m", # zero allocated
> > +"-c", "write -z -u 6m 2m",  # zero hole
> > +# unallocated
> > +disk_qcow2)
> > +print(filter_testfiles(disk_qcow2))
> > +qemu_img_log("map", "--output", "json", disk_qcow2)
>
> This isn’t how iotests work, generally.  When run with -qcow2 -file, it
> should only test qcow2 on file, not raw on file, not raw on nbd. Perhaps
> this way this test could even support other formats than qcow2 and raw.
>

For this type of tests, running the same code with raw, qcow2 (and other
formats)
and using file or nbd is the best way to test this feature - one test
verifies all the
use cases.

I can change this to use the current format (raw, qcow2, ...), protocol
(file, nbd, ...)
and cache value (none, writeback), but I'm not sure how this can work with
the
out files. The output from nbd is different from file. Maybe we need
different out
files for file and nbd (qemu-img-checksum.file.out,

Re: [PATCH 2/3] iotests: Test qemu-img checksum

[Hanna Reitz]

On 01.09.22 16:32, Nir Soffer wrote:

Add simple tests creating an image with all kinds of extents, different
formats, different backing chain, different protocol, and different
image options. Since all images have the same guest visible content they
must have the same checksum.

To help debugging in case of failures, the output includes a json map of
every test image.

Signed-off-by: Nir Soffer 
---
  tests/qemu-iotests/tests/qemu-img-checksum| 149 ++
  .../qemu-iotests/tests/qemu-img-checksum.out  |  74 +
  2 files changed, 223 insertions(+)
  create mode 100755 tests/qemu-iotests/tests/qemu-img-checksum
  create mode 100644 tests/qemu-iotests/tests/qemu-img-checksum.out

diff --git a/tests/qemu-iotests/tests/qemu-img-checksum 
b/tests/qemu-iotests/tests/qemu-img-checksum
new file mode 100755
index 00..3a85ba33f2
--- /dev/null
+++ b/tests/qemu-iotests/tests/qemu-img-checksum
@@ -0,0 +1,149 @@
+#!/usr/bin/env python3
+# group: rw auto quick
+#
+# Test cases for qemu-img checksum.
+#
+# Copyright (C) 2022 Red Hat, Inc.
+#
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 2 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see .
+
+import re
+
+import iotests
+
+from iotests import (
+filter_testfiles,
+qemu_img,
+qemu_img_log,
+qemu_io,
+qemu_nbd_popen,
+)
+
+
+def checksum_available():
+out = qemu_img("--help").stdout
+return re.search(r"\bchecksum .+ filename\b", out) is not None
+
+
+if not checksum_available():
+iotests.notrun("checksum command not available")
+
+iotests.script_initialize(
+supported_fmts=["raw", "qcow2"],
+supported_cache_modes=["none", "writeback"],


It doesn’t work with writeback, though, because it uses -T none below.

Which by the way is a heavy cost, because I usually run tests in tmpfs, 
where this won’t work.  Is there any way of not doing the -T none below?



+supported_protocols=["file", "nbd"],
+required_fmts=["raw", "qcow2"],
+)
+
+print()
+print("=== Test images ===")
+print()
+
+disk_raw = iotests.file_path('raw')
+qemu_img("create", "-f", "raw", disk_raw, "10m")
+qemu_io("-f", "raw",
+"-c", "write -P 0x1 0 2m",  # data
+"-c", "write -P 0x0 2m 2m", # data with zeroes
+"-c", "write -z 4m 2m", # zero allocated
+"-c", "write -z -u 6m 2m",  # zero hole
+# unallocated
+disk_raw)
+print(filter_testfiles(disk_raw))
+qemu_img_log("map", "--output", "json", disk_raw)
+
+disk_qcow2 = iotests.file_path('qcow2')
+qemu_img("create", "-f", "qcow2", disk_qcow2, "10m")
+qemu_io("-f", "qcow2",
+"-c", "write -P 0x1 0 2m",  # data
+"-c", "write -P 0x0 2m 2m", # data with zeroes
+"-c", "write -z 4m 2m", # zero allocated
+"-c", "write -z -u 6m 2m",  # zero hole
+# unallocated
+disk_qcow2)
+print(filter_testfiles(disk_qcow2))
+qemu_img_log("map", "--output", "json", disk_qcow2)


This isn’t how iotests work, generally.  When run with -qcow2 -file, it 
should only test qcow2 on file, not raw on file, not raw on nbd. Perhaps 
this way this test could even support other formats than qcow2 and raw.


Hanna

[PATCH 2/3] iotests: Test qemu-img checksum

[Nir Soffer]

Add simple tests creating an image with all kinds of extents, different
formats, different backing chain, different protocol, and different
image options. Since all images have the same guest visible content they
must have the same checksum.

To help debugging in case of failures, the output includes a json map of
every test image.

Signed-off-by: Nir Soffer 
---
 tests/qemu-iotests/tests/qemu-img-checksum| 149 ++
 .../qemu-iotests/tests/qemu-img-checksum.out  |  74 +
 2 files changed, 223 insertions(+)
 create mode 100755 tests/qemu-iotests/tests/qemu-img-checksum
 create mode 100644 tests/qemu-iotests/tests/qemu-img-checksum.out

diff --git a/tests/qemu-iotests/tests/qemu-img-checksum 
b/tests/qemu-iotests/tests/qemu-img-checksum
new file mode 100755
index 00..3a85ba33f2
--- /dev/null
+++ b/tests/qemu-iotests/tests/qemu-img-checksum
@@ -0,0 +1,149 @@
+#!/usr/bin/env python3
+# group: rw auto quick
+#
+# Test cases for qemu-img checksum.
+#
+# Copyright (C) 2022 Red Hat, Inc.
+#
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 2 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see .
+
+import re
+
+import iotests
+
+from iotests import (
+filter_testfiles,
+qemu_img,
+qemu_img_log,
+qemu_io,
+qemu_nbd_popen,
+)
+
+
+def checksum_available():
+out = qemu_img("--help").stdout
+return re.search(r"\bchecksum .+ filename\b", out) is not None
+
+
+if not checksum_available():
+iotests.notrun("checksum command not available")
+
+iotests.script_initialize(
+supported_fmts=["raw", "qcow2"],
+supported_cache_modes=["none", "writeback"],
+supported_protocols=["file", "nbd"],
+required_fmts=["raw", "qcow2"],
+)
+
+print()
+print("=== Test images ===")
+print()
+
+disk_raw = iotests.file_path('raw')
+qemu_img("create", "-f", "raw", disk_raw, "10m")
+qemu_io("-f", "raw",
+"-c", "write -P 0x1 0 2m",  # data
+"-c", "write -P 0x0 2m 2m", # data with zeroes
+"-c", "write -z 4m 2m", # zero allocated
+"-c", "write -z -u 6m 2m",  # zero hole
+# unallocated
+disk_raw)
+print(filter_testfiles(disk_raw))
+qemu_img_log("map", "--output", "json", disk_raw)
+
+disk_qcow2 = iotests.file_path('qcow2')
+qemu_img("create", "-f", "qcow2", disk_qcow2, "10m")
+qemu_io("-f", "qcow2",
+"-c", "write -P 0x1 0 2m",  # data
+"-c", "write -P 0x0 2m 2m", # data with zeroes
+"-c", "write -z 4m 2m", # zero allocated
+"-c", "write -z -u 6m 2m",  # zero hole
+# unallocated
+disk_qcow2)
+print(filter_testfiles(disk_qcow2))
+qemu_img_log("map", "--output", "json", disk_qcow2)
+
+disk_compressed = iotests.file_path('compressed')
+qemu_img("convert", "-f", "qcow2", "-O", "qcow2", "-c",
+ disk_qcow2, disk_compressed)
+print(filter_testfiles(disk_compressed))
+qemu_img_log("map", "--output", "json", disk_compressed)
+
+disk_base = iotests.file_path('base')
+qemu_img("create", "-f", "raw", disk_base, "10m")
+qemu_io("-f", "raw",
+"-c", "write -P 0x1 0 2m",
+"-c", "write -P 0x0 2m 2m",
+disk_base)
+print(filter_testfiles(disk_base))
+qemu_img_log("map", "--output", "json", disk_base)
+
+disk_top = iotests.file_path('top')
+qemu_img("create", "-f", "qcow2", "-b", disk_base, "-F", "raw",
+ disk_top)
+qemu_io("-f", "qcow2",
+"-c", "write -z 4m 2m",
+"-c", "write -z -u 6m 2m",
+disk_top)
+print(filter_testfiles(disk_top))
+qemu_img_log("map", "--output", "json", disk_top)
+
+print()
+print("=== Checksums - file ===")
+print()
+
+qemu_img_log("checksum", disk_raw)
+qemu_img_log("checksum", disk_qcow2)
+qemu_img_log("checksum", disk_compressed)
+qemu_img_log("checksum", disk_top)
+qemu_img_log("checksum", disk_base)
+
+print()
+print("=== Checksums - nbd ===")
+print()
+
+nbd_sock = iotests.file_path("nbd.sock", base_dir=iotests.sock_dir)
+nbd_uri = f"nbd+unix:///{{}}?socket={nbd_sock}"
+
+with qemu_nbd_popen("-k", nbd_sock, "-f", "raw", "-x", "raw", disk_raw):
+qemu_img_log("checksum", nbd_uri.format("raw"))
+
+with qemu_nbd_popen("-k", nbd_sock, "-f", "qcow2", "-x", "qcow2", disk_qcow2):
+qemu_img_log("checksum", nbd_uri.format("qcow2"))
+
+with qemu_nbd_popen("-k", nbd_sock, "-f", "qcow2", "-x", "compressed", 
disk_compressed):
+qemu_img_log("checksum", nbd_uri.format("compresse