~/mongo $ ls dump
ls: dump: No such file or directory
~/mongo $ ls /data/db
_tmp mongod.lock test.0 test.1 test.ns
~/mongo $ ./mongodump --dbpath /data/db
all dbs
DATABASE: test to dump/test
test.foo to dump/test/foo.bson
1 objects
test.system.indexes to dump/test/system.indexes.bson
1 objects
DATABASE: admin to dump/admin
...
Fri Jun 10 19:57:00 dbexit: really exiting now
~/mongo $ ls dump
admin test
~/mongo $ ls dump/admin
~/mongo $