progress

/dev/md0:
        Version : 1.2
  Creation Time : Thu Jan 31 12:48:57 2013
     Raid Level : raid5
     Array Size : 3906763776 (3725.78 GiB 4000.53 GB)
  Used Dev Size : 1953381888 (1862.89 GiB 2000.26 GB)
   Raid Devices : 3
  Total Devices : 3
    Persistence : Superblock is persistent

    Update Time : Thu Oct  2 00:38:21 2014
          State : clean, degraded, recovering
 Active Devices : 2
Working Devices : 3
 Failed Devices : 0
  Spare Devices : 1

         Layout : left-symmetric
     Chunk Size : 512K

 Rebuild Status : 3% complete

           Name : ubuntu:0
           UUID : b3f3cede:76fa6c93:e503526e:aeb27721
         Events : 1114

    Number   Major   Minor   RaidDevice State
       4       8       16        0      spare rebuilding   /dev/sdb
       1       8       33        1      active sync   /dev/sdc1
       3       8       49        2      active sync   /dev/sdd1