diff options
| -rw-r--r-- | docs/qemu-block-drivers.texi | 4 | ||||
| -rw-r--r-- | qapi/block-core.json | 9 | ||||
| -rw-r--r-- | qemu-img.texi | 4 |
3 files changed, 9 insertions, 8 deletions
diff --git a/docs/qemu-block-drivers.texi b/docs/qemu-block-drivers.texi index 91ab0eceae..c02547e28c 100644 --- a/docs/qemu-block-drivers.texi +++ b/docs/qemu-block-drivers.texi @@ -31,8 +31,8 @@ Supported options: @item preallocation Preallocation mode (allowed values: @code{off}, @code{falloc}, @code{full}). @code{falloc} mode preallocates space for image by calling posix_fallocate(). -@code{full} mode preallocates space for image by writing zeros to underlying -storage. +@code{full} mode preallocates space for image by writing data to underlying +storage. This data may or may not be zero, depending on the storage location. @end table @item qcow2 diff --git a/qapi/block-core.json b/qapi/block-core.json index a5ab38db99..e6edd641f1 100644 --- a/qapi/block-core.json +++ b/qapi/block-core.json @@ -5178,10 +5178,11 @@ # @off: no preallocation # @metadata: preallocate only for metadata # @falloc: like @full preallocation but allocate disk space by -# posix_fallocate() rather than writing zeros. -# @full: preallocate all data by writing zeros to device to ensure disk -# space is really available. @full preallocation also sets up -# metadata correctly. +# posix_fallocate() rather than writing data. +# @full: preallocate all data by writing it to the device to ensure +# disk space is really available. This data may or may not be +# zero, depending on the image format and storage. +# @full preallocation also sets up metadata correctly. # # Since: 2.2 ## diff --git a/qemu-img.texi b/qemu-img.texi index c8e9bba515..b5156d6316 100644 --- a/qemu-img.texi +++ b/qemu-img.texi @@ -666,8 +666,8 @@ Supported options: @item preallocation Preallocation mode (allowed values: @code{off}, @code{falloc}, @code{full}). @code{falloc} mode preallocates space for image by calling posix_fallocate(). -@code{full} mode preallocates space for image by writing zeros to underlying -storage. +@code{full} mode preallocates space for image by writing data to underlying +storage. This data may or may not be zero, depending on the storage location. @end table @item qcow2 |