$ mongo cancer:27022/a
MongoDB shell version: 2.2.3
connecting to: cancer:27022/a
driveFS-2:SECONDARY> rs.slaveOk()
driveFS-2:SECONDARY> db.fs.chunks.find({files_id:NumberLong("5444002714197426176")},{data:0})
{ "_id" : ObjectId("51252590f2ac490dc4e32ec8"), "files_id" : NumberLong("5444002714197426176"), "n" : 0 }
{ "_id" : ObjectId("51252597de30b908b0d23b69"), "files_id" : NumberLong("5444002714197426176"), "n" : 0 }
driveFS-2:SECONDARY> db.system.indexes.find()
{ "v" : 1, "key" : { "_id" : 1 }, "ns" : "a.fs.chunks", "name" : "_id_" }
{ "v" : 1, "key" : { "files_id" : 1, "n" : 1 }, "unique" : true, "ns" : "a.fs.chunks", "name" : "files_id_1_n_1" }