mongos> sh.getBalancerState()
true
mongos> sh.isBalancerRunning()
false

sh.startBalancer()

mongos> sh.getBalancerState
function () {
    var x = db.getSisterDB( "config" ).settings.findOne({ _id: "balancer" } )
    if ( x == null )
        return true;
    return ! x.stopped;
}

mongos> sh.stopBalancer()
Waiting for active hosts...
Waiting for the balancer lock...
Waiting again for active hosts after balancer is off...
mongos> sh.getBalancerState()
false

mongos> sh.startBalancer()
mongos> sh.getBalancerState()
true

mongos> sh.isBalancerRunning()
false

mongos> sh.getBalancerState()
false
mongos> sh.status()
--- Sharding Status ---
  sharding version: {
    "_id" : 1,
    "version" : 3,
    "minCompatibleVersion" : 3,
    "currentVersion" : 4,
    "clusterId" : ObjectId("53b5d3b5d95df3a66a597548")
}
  shards:
    {  "_id" : "shard0000",  "host" : "localhost:30000" }
    {  "_id" : "shard0001",  "host" : "localhost:30001" }
    {  "_id" : "shard0002",  "host" : "localhost:30002" }
  databases:
    {  "_id" : "admin",  "partitioned" : false,  "primary" : "config" }
    {  "_id" : "test",  "partitioned" : false,  "primary" : "shard0001" }
    {  "_id" : "users",  "partitioned" : true,  "primary" : "shard0001" }
        users.userInfo
            shard key: { "_id" : 1 }
            chunks:
                shard0001   2049
            too many chunks to print, use verbose if you want to force print

mongos> sh.isBalancerRunning()
false
mongos> sh.isBalancerRunning()
true

mongos> sh.isBalancerRunning
function () {
    var x = db.getSisterDB("config").locks.findOne({ _id: "balancer" });
    if (x == null) {
        print("config.locks collection empty or missing. be sure you are connected to a mongos");
        return false;
    }
    return x.state > 0;
}

db.getSisterDB("config").locks.findOne({ _id: "balancer" });
{
    "_id" : "balancer",
    "process" : "adamc-mbp:30999:1404425140:16807",
    "state" : 2,
    "ts" : ObjectId("53b5d86fd95df3a66a5975ff"),
    "when" : ISODate("2014-07-03T22:25:51.574Z"),
    "who" : "adamc-mbp:30999:1404425140:16807:Balancer:1622650073",
    "why" : "doing balance round"
}
db.getSisterDB("config").locks.findOne({ _id: "balancer" });
{
    "_id" : "balancer",
    "process" : "adamc-mbp:30999:1404425140:16807",
    "state" : 0,
    "ts" : ObjectId("53b5d86ed95df3a66a5975fe"),
    "when" : ISODate("2014-07-03T22:25:50.528Z"),
    "who" : "adamc-mbp:30999:1404425140:16807:Balancer:1622650073",
    "why" : "doing balance round"
}