The moveChunk is incredible slow and we are moving some chunks for over 24 hours already.

This is one of the entries from the changelog. All are similar with step3 taking extremely long. Other Read/Write activity on the DB is low.

{ "_id" : "data1.local-2011-12-12T21:25:29-574", "server" : "data1.local", "clientAddr" : "", "time" : ISODate("2011-12-12T21:25:29.793Z"), "what" : "moveChunk.to", "ns" : "subscribers.subscribers", "details" : { "min" :

{ "email" : "<censored>" }

, "max" :

{ "email" : "<censored>" }

, "step1" : 1, "step2" : 0, "step3" : 69103, "step4" : 0, "step5" : 182 } }

How can i obtain more information on why step3 takes so long?