在 2024/10/19 0:31, Kevin Wolf 写道:
Am 22.08.2024 um 12:52 hat luzhipeng geschrieben:
issue:https://gitlab.com/qemu-project/qemu/-/issues/1357
empty vmdk only contains metadata, ovftool failed.
So it allocates more one sector for empty disk. the ovftool
command line: ovftool input.ovf output.ova

Signed-off-by: luzhipeng <luzhip...@cestc.cn>

I think this commit message needs more of the information from the bug
report, otherwise it seems unexplainable why adding an empty sector
should make a difference.


I really don't know the real reason, I suspect it's a special requirement of the ovftool tool,
but this issue does exist.

diff --git a/block/vmdk.c b/block/vmdk.c
index 78f6433607..283dee9b49 100644
--- a/block/vmdk.c
+++ b/block/vmdk.c
@@ -2286,7 +2286,7 @@ vmdk_init_extent(BlockBackend *blk, int64_t filesize, 
bool flat, bool compress,
          goto exit;
      }
- ret = blk_co_truncate(blk, le64_to_cpu(header.grain_offset) << 9, false,
+    ret = blk_co_truncate(blk, (le64_to_cpu(header.grain_offset) << 9) + 
BDRV_SECTOR_SIZE,
+                          false, PREALLOC_MODE_OFF, 0, errp);
      if (ret < 0) {
          goto exit;

This is not a good fix. It means that we will always leave an empty
sector after the header, even if more data follows.

Does the problem really only happen with empty images? I think we don't
necessarily add an end-of-stream marker for other images either, we just
align the image size to full sectors at the end of 'qemu-img convert'.

this issue indeed exists.it is not fix for aligning the image size

I wonder if vmdk_co_pwritev_compressed() should be changed to write both
a footer and an explicit end-of-stream marker for streamOptimized images
in the bytes == 0 case.

Kevin






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