mdadm --examine /dev/sd*?

/dev/sda:
   MBR Magic : aa55
Partition[0] :    419430400 sectors at         2048 (type 83)
Partition[1] :     80685744 sectors at    419432448 (type 83)
mdadm: No md superblock detected on /dev/sda1.
mdadm: No md superblock detected on /dev/sda2.
/dev/sdb:
          Magic : a92b4efc
        Version : 1.2
    Feature Map : 0x1
     Array UUID : a36e6432:795a1551:a0b0428c:e9a81645
           Name : pc.home:0  (local to host pc.home)
  Creation Time : Fri Jun  3 08:46:55 2016
     Raid Level : raid5
   Raid Devices : 4

 Avail Dev Size : 1953263024 (931.39 GiB 1000.07 GB)
     Array Size : 2929893888 (2794.16 GiB 3000.21 GB)
  Used Dev Size : 1953262592 (931.39 GiB 1000.07 GB)
    Data Offset : 262144 sectors
   Super Offset : 8 sectors
   Unused Space : before=262056 sectors, after=432 sectors
          State : active
    Device UUID : 163e636e:daea0d9e:0515cab0:d1218d80

Internal Bitmap : 8 sectors from superblock
    Update Time : Sat Jul 16 15:43:26 2016
  Bad Block Log : 512 entries available at offset 72 sectors
       Checksum : 75dc4f26 - correct
         Events : 27763

         Layout : left-symmetric
     Chunk Size : 512K

   Device Role : Active device 0
   Array State : AAA. ('A' == active, '.' == missing, 'R' == replacing)
/dev/sdc:
          Magic : a92b4efc
        Version : 1.2
    Feature Map : 0x1
     Array UUID : a36e6432:795a1551:a0b0428c:e9a81645
           Name : pc.home:0  (local to host pc.home)
  Creation Time : Fri Jun  3 08:46:55 2016
     Raid Level : raid5
   Raid Devices : 4

 Avail Dev Size : 1953263024 (931.39 GiB 1000.07 GB)
     Array Size : 2929893888 (2794.16 GiB 3000.21 GB)
  Used Dev Size : 1953262592 (931.39 GiB 1000.07 GB)
    Data Offset : 262144 sectors
   Super Offset : 8 sectors
   Unused Space : before=262056 sectors, after=432 sectors
          State : active
    Device UUID : ebef84e6:3fa78e65:67b04f60:8adf2076

Internal Bitmap : 8 sectors from superblock
    Update Time : Sat Jul 16 15:43:26 2016
  Bad Block Log : 512 entries available at offset 72 sectors
       Checksum : 5a98167c - correct
         Events : 27763

         Layout : left-symmetric
     Chunk Size : 512K

   Device Role : Active device 1
   Array State : AAA. ('A' == active, '.' == missing, 'R' == replacing)
mdadm: No md superblock detected on /dev/sdd.
/dev/sde:
          Magic : a92b4efc
        Version : 1.2
    Feature Map : 0x1
     Array UUID : a36e6432:795a1551:a0b0428c:e9a81645
           Name : pc.home:0  (local to host pc.home)
  Creation Time : Fri Jun  3 08:46:55 2016
     Raid Level : raid5
   Raid Devices : 4

 Avail Dev Size : 1953263024 (931.39 GiB 1000.07 GB)
     Array Size : 2929893888 (2794.16 GiB 3000.21 GB)
  Used Dev Size : 1953262592 (931.39 GiB 1000.07 GB)
    Data Offset : 262144 sectors
   Super Offset : 8 sectors
   Unused Space : before=262056 sectors, after=432 sectors
          State : active
    Device UUID : 58cf6b72:6c9def35:232282fc:028f68f3

Internal Bitmap : 8 sectors from superblock
    Update Time : Sat Jul 16 15:43:26 2016
  Bad Block Log : 512 entries available at offset 72 sectors
       Checksum : d05a0d4b - correct
         Events : 27763

         Layout : left-symmetric
     Chunk Size : 512K

   Device Role : Active device 2
   Array State : AAA. ('A' == active, '.' == missing, 'R' == replacing)
/dev/sdf:
          Magic : a92b4efc
        Version : 1.2
    Feature Map : 0x1
     Array UUID : a36e6432:795a1551:a0b0428c:e9a81645
           Name : pc.home:0  (local to host pc.home)
  Creation Time : Fri Jun  3 08:46:55 2016
     Raid Level : raid5
   Raid Devices : 4

 Avail Dev Size : 1953263024 (931.39 GiB 1000.07 GB)
     Array Size : 2929893888 (2794.16 GiB 3000.21 GB)
  Used Dev Size : 1953262592 (931.39 GiB 1000.07 GB)
    Data Offset : 262144 sectors
   Super Offset : 8 sectors
   Unused Space : before=262056 sectors, after=432 sectors
          State : clean
    Device UUID : 212d9261:8e3ba4fb:0e1276ae:d5613fcc

Internal Bitmap : 8 sectors from superblock
    Update Time : Mon Jun 20 23:06:25 2016
  Bad Block Log : 512 entries available at offset 72 sectors
       Checksum : fdc8986 - correct
         Events : 2346

         Layout : left-symmetric
     Chunk Size : 512K

   Device Role : Active device 3
   Array State : AAAA ('A' == active, '.' == missing, 'R' == replacing)