sudo mdadm --detail /dev/md0
[sudo] password for user:
/dev/md0:
        Version : 1.2
  Creation Time : Thu Dec 17 20:36:24 2015
     Raid Level : raid5
     Array Size : 15627542528 (14903.59 GiB 16002.60 GB)
  Used Dev Size : 3906885632 (3725.90 GiB 4000.65 GB)
   Raid Devices : 5
  Total Devices : 4
    Persistence : Superblock is persistent

  Intent Bitmap : Internal

    Update Time : Sat May  4 17:12:54 2019
          State : clean, degraded
 Active Devices : 4
Working Devices : 4
 Failed Devices : 0
  Spare Devices : 0

         Layout : left-symmetric
     Chunk Size : 512K

           Name : Media2:0
           UUID : 47c55f8f:44a21514:9ec18c58:4e083225
         Events : 750444

    Number   Major   Minor   RaidDevice State
       0       8       17        0      active sync   /dev/sdb1
       1       8       65        1      active sync   /dev/sde1
       2       8       49        2      active sync   /dev/sdd1
       3       0        0        3      removed
       5       8       33        4      active sync   /dev/sdc1