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[Matthew Booth <mbooth@xxxxxxxxxx>]

Public bug reported:

N.B. This is based purely on code inspection. A reasonable resolution
would be to point out that I've misunderstood something and it's
actually fine. I'm filing this bug because it's potentially a subtle
data corruptor, and I'd like more eyes on it.

The snapshot code in vmwareapi/vmops.py does:

1. snapshot
2. copy disk image to vmware
3. delete snapshot
4. copy disk image from vmware to glance

I think the problem is in step 2. I don't see how it's copying the
snapshot it just created rather than the live disk image. i.e. I don't
think step 2 is copying the snapshot it created in step 1. It's possible
that there's some subtlety to do with path names here, but in that case
it could still do with a comment.

If it is in fact copying the live image, it would normally work.
However, this would potentially be a subtle data corruptor. For example,
consider that a file's data was towards the beginning of a disk, but its
metadata was towards the end of the disk. If the VM guest creates the
file during the copy operation, it copies the metadata at the end of the
disk, but misses the contents at the beginning of the disk.

** Affects: nova
     Importance: Undecided
         Status: New


** Tags: vmware

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Engineering Team, which is subscribed to OpenStack Compute (nova).
https://bugs.launchpad.net/bugs/1337798

Title:
  VMware: snapshot operation copies a live image

Status in OpenStack Compute (Nova):
  New

Bug description:
  N.B. This is based purely on code inspection. A reasonable resolution
  would be to point out that I've misunderstood something and it's
  actually fine. I'm filing this bug because it's potentially a subtle
  data corruptor, and I'd like more eyes on it.

  The snapshot code in vmwareapi/vmops.py does:

  1. snapshot
  2. copy disk image to vmware
  3. delete snapshot
  4. copy disk image from vmware to glance

  I think the problem is in step 2. I don't see how it's copying the
  snapshot it just created rather than the live disk image. i.e. I don't
  think step 2 is copying the snapshot it created in step 1. It's
  possible that there's some subtlety to do with path names here, but in
  that case it could still do with a comment.

  If it is in fact copying the live image, it would normally work.
  However, this would potentially be a subtle data corruptor. For
  example, consider that a file's data was towards the beginning of a
  disk, but its metadata was towards the end of the disk. If the VM
  guest creates the file during the copy operation, it copies the
  metadata at the end of the disk, but misses the contents at the
  beginning of the disk.

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