SSVM under XenServer 6.5SP1 and ACS 4.9 was found to download the built-in template multiple times (concurrently).
Once this has happened the built-in template could not be used to deploy VMs as couldstack found 2 VHDs in the directory and threw an insufficient capacity exception.
The template was being downloaded locally (at 35MB/s) with no drop outs.
There are in fact multiple issues here:
1. SSVM not behaving properly and downloading mulitple copies.
2. Why is cloudstack 'blindly' looking in a directory for a VHD to pick up. The full path and filename of the VHD is in its data base, it should use it.
3. what is template.properties for? the filename is contained within it, as is an MDSUM to check for consistency
4. the filename in template.properties is different to the one in the database.