diff options
| -rw-r--r-- | hmp-commands.hx | 5 | ||||
| -rw-r--r-- | qapi-schema.json | 7 | ||||
| -rw-r--r-- | qemu-img.texi | 7 | ||||
| -rw-r--r-- | qmp-commands.hx | 39 |
4 files changed, 57 insertions, 1 deletions
diff --git a/hmp-commands.hx b/hmp-commands.hx index feca0847d0..f3fc514427 100644 --- a/hmp-commands.hx +++ b/hmp-commands.hx @@ -35,6 +35,11 @@ STEXI @item commit @findex commit Commit changes to the disk images (if -snapshot is used) or backing files. +If the backing file is smaller than the snapshot, then the backing file will be +resized to be the same size as the snapshot. If the snapshot is smaller than +the backing file, the backing file will not be truncated. If you want the +backing file to match the size of the smaller snapshot, you can safely truncate +it yourself once the commit operation successfully completes. ETEXI { diff --git a/qapi-schema.json b/qapi-schema.json index e04949de52..1ff607ac3c 100644 --- a/qapi-schema.json +++ b/qapi-schema.json @@ -1994,6 +1994,13 @@ # user needs to complete the job with the block-job-complete # command after getting the ready event. (Since 2.0) # +# If the base image is smaller than top, then the base image +# will be resized to be the same size as top. If top is +# smaller than the base image, the base will not be +# truncated. If you want the base image size to match the +# size of the smaller top, you can safely truncate it +# yourself once the commit operation successfully completes. +# # # @speed: #optional the maximum speed, in bytes per second # diff --git a/qemu-img.texi b/qemu-img.texi index f86a86d916..526d56a458 100644 --- a/qemu-img.texi +++ b/qemu-img.texi @@ -142,7 +142,12 @@ it doesn't need to be specified separately in this case. @item commit [-f @var{fmt}] [-t @var{cache}] @var{filename} -Commit the changes recorded in @var{filename} in its base image. +Commit the changes recorded in @var{filename} in its base image or backing file. +If the backing file is smaller than the snapshot, then the backing file will be +resized to be the same size as the snapshot. If the snapshot is smaller than +the backing file, the backing file will not be truncated. If you want the +backing file to match the size of the smaller snapshot, you can safely truncate +it yourself once the commit operation successfully completes. @item compare [-f @var{fmt}] [-F @var{fmt}] [-p] [-s] [-q] @var{filename1} @var{filename2} diff --git a/qmp-commands.hx b/qmp-commands.hx index 4f2825017c..cce6b81da4 100644 --- a/qmp-commands.hx +++ b/qmp-commands.hx @@ -966,6 +966,45 @@ EQMP .mhandler.cmd_new = qmp_marshal_input_block_commit, }, +SQMP +block-commit +------------ + +Live commit of data from overlay image nodes into backing nodes - i.e., writes +data between 'top' and 'base' into 'base'. + +Arguments: + +- "device": The device's ID, must be unique (json-string) +- "base": The file name of the backing image to write data into. + If not specified, this is the deepest backing image + (json-string, optional) +- "top": The file name of the backing image within the image chain, + which contains the topmost data to be committed down. + + If top == base, that is an error. + If top == active, the job will not be completed by itself, + user needs to complete the job with the block-job-complete + command after getting the ready event. (Since 2.0) + + If the base image is smaller than top, then the base image + will be resized to be the same size as top. If top is + smaller than the base image, the base will not be + truncated. If you want the base image size to match the + size of the smaller top, you can safely truncate it + yourself once the commit operation successfully completes. + (json-string) +- "speed": the maximum speed, in bytes per second (json-int, optional) + + +Example: + +-> { "execute": "block-commit", "arguments": { "device": "virtio0", + "top": "/tmp/snap1.qcow2" } } +<- { "return": {} } + +EQMP + { .name = "drive-backup", .args_type = "sync:s,device:B,target:s,speed:i?,mode:s?,format:s?," |