From 37222900743962e146a82b7077a18c3f39859a19 Mon Sep 17 00:00:00 2001 From: Jeff Cody Date: Fri, 24 Jan 2014 09:02:37 -0500 Subject: block: update block commit documentation regarding image truncation This updates the documentation for commiting snapshot images. Specifically, this highlights what happens when the base image is either smaller or larger than the snapshot image being committed. In the case of the base image being smaller, it is resized to the larger size of the snapshot image. In the case of the base image being larger, it is not resized automatically, but once the commit has completed it is safe for the user to truncate the base image. Signed-off-by: Jeff Cody Reviewed-by: Fam Zheng Reviewed-by: Eric Blake Signed-off-by: Kevin Wolf --- hmp-commands.hx | 5 +++++ 1 file changed, 5 insertions(+) (limited to 'hmp-commands.hx') 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 { -- cgit v1.2.1