What is the maximum number of snapshots?

DSS up from version up49:

The total number of snapshots is dependent on the LVM, but 255 is a safe
number. There are, however, definite limitations as to the number of ACTIVE
snapshots:

32bit and 64bit system:
- 10 per LV
- 20 per system

DSS up to version up48:

Version up to up48 have different limitations as to the number of ACTIVE
snapshots:

32bit system:
- 10 per LV
- 20 per system

64bit system:
- 1 per LV
- 10 per system

iSCSI-R3, NAS-R3 and XSR: similarly 10 per lv and 20 per system, but there is no 64bit mode available.

NAS Enterprise:

99 snapshots can be configured; the number of active snapshots is not set (it depends on volume size and available system memory). In most cases it is about 20 snapshots per system and 20 per LV.