Backport
LP: #1893898 describes missing vmtools version from the vmdk headers.
The version should be added as ddb.toolsVersion = "2147483647" however
the sed was no longer replacing a ddb.comment field with the tools
version. Rather than subbing ddb.comment with toolsVersion, this commit
deletes ddb.comment (which the comment mentions could cause errors),
and adds the correct value. There was no visibility into the descriptor
during hook creation, so debug statements were added. This allows us to
quickly verify in the logs that bad statements are removed (the possibly
offending comments), as well as ensuring that the toolsVersion is added
Vagrant images were previously put at 10G, but this was a regression
from Trusty, in which they were 40G. This made it a tough sell for
users to upgrade if they were using a Ubuntu desktop experience.
This change does not impact disk usage as Vagrant with the virtualbox
provider dynamically allocates space with the VMDK. On a test system,
the VMDK took up 1.1G of disk space according to df, and after
creating a 2G file in Vagrant, the VMDK grew to 3.1G.
Therefore, users who are running on a system with little free space will
not see adverse effects if they upgrade to a new vagrant image
Older version of vmdk-stream-converter has an incorrect header. The
original sed command replaced the incorrect "Description File" comment
with the correct "Disk DescriptorFile".
