X-Git-Url: https://git.proxmox.com/?a=blobdiff_plain;f=qemu-img.texi;h=c81db3e81cd0f9a4ec356790682f3bda7694b37e;hb=a6c76285f2e41535527a46edf4d158a2779545e1;hp=449a19c71041fe2fb1a2e42a68fed01e95b42765;hpb=1ec20c2a3aa5b90522d15fccf7f052a90f70ddaa;p=mirror_qemu.git diff --git a/qemu-img.texi b/qemu-img.texi index 449a19c710..c81db3e81c 100644 --- a/qemu-img.texi +++ b/qemu-img.texi @@ -137,6 +137,28 @@ Parameters to convert subcommand: @item -n Skip the creation of the target volume +@item -m +Number of parallel coroutines for the convert process +@item -W +Allow out-of-order writes to the destination. This option improves performance, +but is only recommended for preallocated devices like host devices or other +raw block devices. +@end table + +Parameters to dd subcommand: + +@table @option + +@item bs=@var{block_size} +defines the block size +@item count=@var{blocks} +sets the number of input blocks to copy +@item if=@var{input} +sets the input file +@item of=@var{output} +sets the output file +@item skip=@var{blocks} +sets the number of input blocks to skip @end table Command description: @@ -280,7 +302,7 @@ Error on reading data @end table -@item convert [-c] [-p] [-n] [-f @var{fmt}] [-t @var{cache}] [-T @var{src_cache}] [-O @var{output_fmt}] [-o @var{options}] [-s @var{snapshot_id_or_name}] [-l @var{snapshot_param}] [-S @var{sparse_size}] @var{filename} [@var{filename2} [...]] @var{output_filename} +@item convert [-c] [-p] [-n] [-f @var{fmt}] [-t @var{cache}] [-T @var{src_cache}] [-O @var{output_fmt}] [-o @var{options}] [-s @var{snapshot_id_or_name}] [-l @var{snapshot_param}] [-m @var{num_coroutines}] [-W] [-S @var{sparse_size}] @var{filename} [@var{filename2} [...]] @var{output_filename} Convert the disk image @var{filename} or a snapshot @var{snapshot_param}(@var{snapshot_id_or_name} is deprecated) to disk image @var{output_filename} using format @var{output_fmt}. It can be optionally compressed (@code{-c} @@ -310,6 +332,25 @@ skipped. This is useful for formats such as @code{rbd} if the target volume has already been created with site specific options that cannot be supplied through qemu-img. +Out of order writes can be enabled with @code{-W} to improve performance. +This is only recommended for preallocated devices like host devices or other +raw block devices. Out of order write does not work in combination with +creating compressed images. + +@var{num_coroutines} specifies how many coroutines work in parallel during +the convert process (defaults to 8). + +@item dd [-f @var{fmt}] [-O @var{output_fmt}] [bs=@var{block_size}] [count=@var{blocks}] [skip=@var{blocks}] if=@var{input} of=@var{output} + +Dd copies from @var{input} file to @var{output} file converting it from +@var{fmt} format to @var{output_fmt} format. + +The data is by default read and written using blocks of 512 bytes but can be +modified by specifying @var{block_size}. If count=@var{blocks} is specified +dd will stop reading input after reading @var{blocks} input blocks. + +The size syntax is similar to dd(1)'s size syntax. + @item info [-f @var{fmt}] [--output=@var{ofmt}] [--backing-chain] @var{filename} Give information about the disk image @var{filename}. Use it in