on page : http://www.aerospike.com/docs/reference/configuration/
for “file” configuration
file [static] Context: namespace Subcontext: storage-engine device Data file path on rotational disk (using a file system). More Information Example: Persist to Two Files device /mnt/disk1/myfile1.dat device /mnt/disk2/myfile2.dat Tip: You can specify multiple files per namespace. Warning: You may not use both device in file in the same namespace.
The device in bold should be file, right?