When adding a new data storage domain without stating the values of Discard After Delete (DAD) and storage format, their default values used to be calculated according to the data center version of the host that added the storage domain:
DAD = true for dc >= 4.1, otherwise false.
Storage format = V4 for dc >= 4.1, otherwise V3.
This was a bad heuristic since the dc of the host that added the domain is a random dc and is not necessarily the dc that the domain will be later attached to.
Therefore, the logic was changed to be as follows:
- The default storage format for new data domains will be the latest format (now it is V4). For non data domains, nothing has changed here - V1 was and will remain the default value.
- The default value of DAD will be calculated according to the storage format: true for >= V4 and otherwise false.