I've had an case open with tech support. Right after upgrading to v9 we experiencing failing backups. After digging we found that only vCloud Thin & Fast provisioned VM's (gold clone principle) were sometimes failing backup.
It has something to do with an under the hood integrity check (mutex?) within Veeam, which with v8 the success pass was optional, but has become mandatory in v9. So we've always had problems with the check failing because of lack of processing time, but it didn't fail the job, but now at v9 it does. Because of the disk payout, having multiple layers due to fast provisioned disks, the mutex takes more time then Veeam anticipated. We eventually applied an registry fix to allow Veeam more time to do the check, now the backup no longer fails.
So, I've asked Veeam to implement an permanent solution for this. But they stated that my situation was to unique to apply a permanent fix. So that’s why I wanted to asked the community if someone else is having the same setup: vcloud with thin and fast provisioned disks.
To my opinion, Veeam states to support vCloud, they should support fast provisioned disks and implement a permanent fix. No registry tweaking.
Veeam ProPartner and Cloud Connect Provider