3a20013fbb
When creating an image with preallocation "off" or "falloc", the first
block of the image is typically not allocated. When using Gluster
storage backed by XFS filesystem, reading this block using direct I/O
succeeds regardless of request length, fooling alignment detection.
In this case we fallback to a safe value (4096) instead of the optimal
value (512), which may lead to unneeded data copying when aligning
requests. Allocating the first block avoids the fallback.
Since we allocate the first block even with preallocation=off, we no
longer create images with zero disk size:
$ ./qemu-img create -f raw test.raw 1g
Formatting 'test.raw', fmt=raw size=1073741824
$ ls -lhs test.raw
4.0K -rw-r--r--. 1 nsoffer nsoffer 1.0G Aug 16 23:48 test.raw
And converting the image requires additional cluster:
$ ./qemu-img measure -f raw -O qcow2 test.raw
required size: 458752
fully allocated size: 1074135040
When using format like vmdk with multiple files per image, we allocate
one block per file:
$ ./qemu-img create -f vmdk -o subformat=twoGbMaxExtentFlat test.vmdk 4g
Formatting 'test.vmdk', fmt=vmdk size=4294967296 compat6=off hwversion=undefined subformat=twoGbMaxExtentFlat
$ ls -lhs test*.vmdk
4.0K -rw-r--r--. 1 nsoffer nsoffer 2.0G Aug 27 03:23 test-f001.vmdk
4.0K -rw-r--r--. 1 nsoffer nsoffer 2.0G Aug 27 03:23 test-f002.vmdk
4.0K -rw-r--r--. 1 nsoffer nsoffer 353 Aug 27 03:23 test.vmdk
I did quick performance test for copying disks with qemu-img convert to
new raw target image to Gluster storage with sector size of 512 bytes:
for i in $(seq 10); do
rm -f dst.raw
sleep 10
time ./qemu-img convert -f raw -O raw -t none -T none src.raw dst.raw
done
Here is a table comparing the total time spent:
Type Before(s) After(s) Diff(%)
---------------------------------------
real 530.028 469.123 -11.4
user 17.204 10.768 -37.4
sys 17.881 7.011 -60.7
We can see very clear improvement in CPU usage.
Signed-off-by: Nir Soffer <nsoffer@redhat.com>
Message-id: 20190827010528.8818-2-nsoffer@redhat.com
Reviewed-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
311 lines
7.7 KiB
Plaintext
311 lines
7.7 KiB
Plaintext
QA output created by 178
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== Input validation ==
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Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824
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qemu-img: Either --size N or one filename must be specified.
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qemu-img: --size N cannot be used together with a filename.
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qemu-img: At most one filename argument is allowed.
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qemu-img: --object, --image-opts, -f, and -l require a filename argument.
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qemu-img: --object, --image-opts, -f, and -l require a filename argument.
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qemu-img: --object, --image-opts, -f, and -l require a filename argument.
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qemu-img: --object, --image-opts, -f, and -l require a filename argument.
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qemu-img: Invalid option list: ,
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qemu-img: Invalid parameter 'snapshot.foo'
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qemu-img: Failed in parsing snapshot param 'snapshot.foo'
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qemu-img: --output must be used with human or json as argument.
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qemu-img: Image size must be less than 8 EiB!
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qemu-img: Unknown file format 'foo'
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== Size calculation for a new file (human) ==
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required size: 196608
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fully allocated size: 196608
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required size: 589824
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fully allocated size: 2148073472
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required size: 10747904
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fully allocated size: 68730224640
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required size: 42205184
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fully allocated size: 274920112128
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required size: 168034304
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fully allocated size: 1099679662080
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required size: 343650009088
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fully allocated size: 2252143463694336
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qemu-img: The image size is too large (try using a larger cluster size)
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== Empty qcow2 input image (human) ==
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Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=0
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required size: 196608
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fully allocated size: 196608
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converted image file size in bytes: 196608
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== qcow2 input image with data (human) ==
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Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824
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required size: 393216
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fully allocated size: 1074135040
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wrote 512/512 bytes at offset 512
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512 bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
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wrote 65536/65536 bytes at offset 65536
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64 KiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
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wrote 64512/64512 bytes at offset 134217728
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63 KiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
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required size: 589824
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fully allocated size: 1074135040
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converted image file size in bytes: 524288
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== qcow2 input image with internal snapshot (human) ==
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required size: 524288
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fully allocated size: 1074135040
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converted image file size in bytes: 458752
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== qcow2 input image and a backing file (human) ==
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required size: 1074135040
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fully allocated size: 1074135040
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== qcow2 input image and LUKS encryption ==
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required size: 2686976
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fully allocated size: 1076232192
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== qcow2 input image and preallocation (human) ==
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required size: 1074135040
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fully allocated size: 1074135040
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converted image file size in bytes: 1074135040
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== Fully-allocated qcow2 input image (human) ==
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Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=8388608
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wrote 8388608/8388608 bytes at offset 0
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8 MiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
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required size: 8716288
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fully allocated size: 8716288
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converted image file size in bytes: 8716288
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== Empty raw input image (human) ==
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Formatting 'TEST_DIR/t.qcow2', fmt=IMGFMT size=0
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required size: 196608
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fully allocated size: 196608
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converted image file size in bytes: 196608
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== raw input image with data (human) ==
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Formatting 'TEST_DIR/t.qcow2', fmt=IMGFMT size=1073741824
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required size: 458752
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fully allocated size: 1074135040
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wrote 512/512 bytes at offset 512
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512 bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
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wrote 65536/65536 bytes at offset 65536
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64 KiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
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wrote 64512/64512 bytes at offset 134217728
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63 KiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
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required size: 589824
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fully allocated size: 1074135040
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converted image file size in bytes: 524288
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== raw input image and a backing file (human) ==
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required size: 1074135040
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fully allocated size: 1074135040
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== raw input image and LUKS encryption ==
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required size: 2686976
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fully allocated size: 1076232192
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== raw input image and preallocation (human) ==
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required size: 1074135040
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fully allocated size: 1074135040
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converted image file size in bytes: 1074135040
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== Fully-allocated raw input image (human) ==
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Formatting 'TEST_DIR/t.qcow2', fmt=IMGFMT size=8388608
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wrote 8388608/8388608 bytes at offset 0
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8 MiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
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required size: 8716288
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fully allocated size: 8716288
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converted image file size in bytes: 8716288
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== Size calculation for a new file (json) ==
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{
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"required": 196608,
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"fully-allocated": 196608
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}
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{
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"required": 589824,
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"fully-allocated": 2148073472
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}
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{
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"required": 10747904,
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"fully-allocated": 68730224640
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}
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{
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"required": 42205184,
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"fully-allocated": 274920112128
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}
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{
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"required": 168034304,
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"fully-allocated": 1099679662080
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}
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{
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"required": 343650009088,
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"fully-allocated": 2252143463694336
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}
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qemu-img: The image size is too large (try using a larger cluster size)
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== Empty qcow2 input image (json) ==
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Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=0
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{
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"required": 196608,
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"fully-allocated": 196608
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}
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converted image file size in bytes: 196608
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== qcow2 input image with data (json) ==
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Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824
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{
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"required": 393216,
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"fully-allocated": 1074135040
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}
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wrote 512/512 bytes at offset 512
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512 bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
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wrote 65536/65536 bytes at offset 65536
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64 KiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
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wrote 64512/64512 bytes at offset 134217728
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63 KiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
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{
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"required": 589824,
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"fully-allocated": 1074135040
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}
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converted image file size in bytes: 524288
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== qcow2 input image with internal snapshot (json) ==
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{
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"required": 524288,
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"fully-allocated": 1074135040
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}
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converted image file size in bytes: 458752
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== qcow2 input image and a backing file (json) ==
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{
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"required": 1074135040,
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"fully-allocated": 1074135040
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}
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== qcow2 input image and LUKS encryption ==
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{
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"required": 2686976,
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"fully-allocated": 1076232192
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}
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== qcow2 input image and preallocation (json) ==
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{
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"required": 1074135040,
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"fully-allocated": 1074135040
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}
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converted image file size in bytes: 1074135040
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== Fully-allocated qcow2 input image (json) ==
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Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=8388608
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wrote 8388608/8388608 bytes at offset 0
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8 MiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
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{
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"required": 8716288,
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"fully-allocated": 8716288
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}
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converted image file size in bytes: 8716288
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== Empty raw input image (json) ==
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Formatting 'TEST_DIR/t.qcow2', fmt=IMGFMT size=0
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{
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"required": 196608,
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"fully-allocated": 196608
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}
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converted image file size in bytes: 196608
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== raw input image with data (json) ==
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Formatting 'TEST_DIR/t.qcow2', fmt=IMGFMT size=1073741824
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{
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"required": 458752,
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"fully-allocated": 1074135040
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}
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wrote 512/512 bytes at offset 512
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512 bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
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wrote 65536/65536 bytes at offset 65536
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64 KiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
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wrote 64512/64512 bytes at offset 134217728
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63 KiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
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{
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"required": 589824,
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"fully-allocated": 1074135040
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}
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converted image file size in bytes: 524288
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== raw input image and a backing file (json) ==
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{
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"required": 1074135040,
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"fully-allocated": 1074135040
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}
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== raw input image and LUKS encryption ==
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{
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"required": 2686976,
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"fully-allocated": 1076232192
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}
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== raw input image and preallocation (json) ==
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{
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"required": 1074135040,
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"fully-allocated": 1074135040
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}
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converted image file size in bytes: 1074135040
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== Fully-allocated raw input image (json) ==
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Formatting 'TEST_DIR/t.qcow2', fmt=IMGFMT size=8388608
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wrote 8388608/8388608 bytes at offset 0
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8 MiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
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{
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"required": 8716288,
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"fully-allocated": 8716288
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}
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converted image file size in bytes: 8716288
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*** done
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