Upgrading to ArangoDB 3.4

Upon upgrading from 3.3 to 3.4, the following storage engine-specific data conversion taskswill be executed:

The conversion will read each datafile sequentially and write out a new datafile in thenew format sequentially. This means the disk will be involved, but both reading andwriting are done in a sequential fashion. Preliminary tests have shown that it will need at most 2-3 times as long as it takes to copy the database directory.

Preliminary tests have shown that the conversion can process about 500K to 1M geo index entries per second on commodity hardware.