motorhead/qemu
1
0
Fork 0
mirror of https://github.com/Motorhead1991/qemu.git synced 2025-08-03 07:43:54 -06:00
Code Issues Projects Releases Packages Wiki Activity Actions

qemu-img: Add --target-is-zero to convert

Browse source 
In many cases the target of a convert operation is a newly provisioned
target that the user knows is blank (reads as zero). In this situation
there is no requirement for qemu-img to wastefully zero out the entire
device.

Add a new option, --target-is-zero, allowing the user to indicate that
an existing target device will return zeros for all reads.

Signed-off-by: David Edmondson <david.edmondson@oracle.com>
Message-Id: <20200205110248.2009589-2-david.edmondson@oracle.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
This commit is contained in:
David Edmondson 2020-02-05 11:02:48 +00:00 • committed by Max Reitz
parent facda5443f
commit 168468fe19
3 changed files with 33 additions and 6 deletions
Download patch file Download diff file Expand all files Collapse all files

9
docs/interop/qemu-img.rst
View file

@ -214,6 +214,13 @@ Parameters to convert subcommand:
will still be printed. Areas that cannot be read from the source will be
treated as containing only zeroes.
.. option:: --target-is-zero
Assume that reading the destination image will always return
zeros. This parameter is mutually exclusive with a destination image
that has a backing file. It is required to also use the ``-n``
parameter to skip image creation.
Parameters to dd subcommand:
.. program:: qemu-img-dd
@ -366,7 +373,7 @@ Command description:
4
Error on reading data
.. option:: convert [--object OBJECTDEF] [--image-opts] [--target-image-opts] [-U] [-C] [-c] [-p] [-q] [-n] [-f FMT] [-t CACHE] [-T SRC_CACHE] [-O OUTPUT_FMT] [-B BACKING_FILE] [-o OPTIONS] [-l SNAPSHOT_PARAM] [-S SPARSE_SIZE] [-m NUM_COROUTINES] [-W] FILENAME [FILENAME2 [...]] OUTPUT_FILENAME
.. option:: convert [--object OBJECTDEF] [--image-opts] [--target-image-opts] [--target-is-zero] [-U] [-C] [-c] [-p] [-q] [-n] [-f FMT] [-t CACHE] [-T SRC_CACHE] [-O OUTPUT_FMT] [-B BACKING_FILE] [-o OPTIONS] [-l SNAPSHOT_PARAM] [-S SPARSE_SIZE] [-m NUM_COROUTINES] [-W] FILENAME [FILENAME2 [...]] OUTPUT_FILENAME
Convert the disk image *FILENAME* or a snapshot *SNAPSHOT_PARAM*
to disk image *OUTPUT_FILENAME* using format *OUTPUT_FMT*. It can