Block should be additionally replicated on 1 more rack(s)

[风雨无阻]

HI all:


After the cluster configuration rack awareness,run " hadoop fsck / " 
A lot of the following error occurred:
 Replica placement policy is violated for blk_-1267324897180563985_11130670. 
Block should be additionally replicated on 1 more rack(s).


Online said "The reason is that three copies on the same rack" .
The solution is now:
hadoop dfs -setrep 4  
/user/hive/warehouse/tbl_add_av_errorlog_android/dt=2013-08-24/000004_0
sleep N
hadoop dfs -setrep 3 
/user/hive/warehouse/tbl_add_av_errorlog_android/dt=2013-08-24/000004_0
But the speed is very slow。‍


What is a better good way to make HDFS become healthy‍?‍



Thanks,‍

Ma Jian