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authorHu Tao <hutao@cn.fujitsu.com>2014-09-10 17:05:48 +0800
committerKevin Wolf <kwolf@redhat.com>2014-09-12 15:43:06 +0200
commit06247428be8037b3739280f82cb29efe8397695f (patch)
treeea73080ed5104a4fbb89519da56469566b3a141c /qemu-img.texi
parentffeaac9b4e23a3033e8120cc34bacadc09487f1b (diff)
downloadqemu-arm-06247428be8037b3739280f82cb29efe8397695f.tar.gz
raw-posix: Add falloc and full preallocation option
This patch adds a new option preallocation for raw format, and implements falloc and full preallocation. Signed-off-by: Hu Tao <hutao@cn.fujitsu.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Diffstat (limited to 'qemu-img.texi')
-rw-r--r--qemu-img.texi9
1 files changed, 9 insertions, 0 deletions
diff --git a/qemu-img.texi b/qemu-img.texi
index cc4668e64f..d64d05edda 100644
--- a/qemu-img.texi
+++ b/qemu-img.texi
@@ -419,6 +419,15 @@ Linux or NTFS on Windows), then only the written sectors will reserve
space. Use @code{qemu-img info} to know the real size used by the
image or @code{ls -ls} on Unix/Linux.
+Supported options:
+@table @code
+@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.
+@end table
+
@item qcow2
QEMU image format, the most versatile format. Use it to have smaller
images (useful if your filesystem does not supports holes, for example