1. audit

lsscsi -s
[0:0:0:0]    disk    ATA      MTFDDAK240MBB-1A MB33  /dev/sda    240GB
[1:0:0:0]    cd/dvd  HL-DT-ST RW/DVD MU10N     1.05  /dev/sr0        -
[5:0:0:0]    disk    JMicron                   0000  /dev/sdb   4.00TB
fdisk -l /dev/sdb
Disk /dev/sdb: 3.7 TiB, 4000787030016 bytes, 7814037168 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disklabel type: gpt
Disk identifier: 7B86B6FF-30BD-46EE-AD2B-2B531135A3F1

Device       Start        End    Sectors  Size Type
/dev/sdb1     2048    4982527    4980480  2.4G Linux RAID
/dev/sdb2  4982528    9176831    4194304    2G Linux RAID
/dev/sdb5  9453280 7813830239 7804376960  3.6T Linux RAID
mdadm -E /dev/sdb5
/dev/sdb5:
          Magic : a92b4efc
        Version : 1.2
    Feature Map : 0x0
     Array UUID : ea184280:8651a5e3:3b29dee4:c957cc20
           Name : DiskStation:2
  Creation Time : Tue Feb 21 15:55:57 2017
     Raid Level : raid1
   Raid Devices : 2

 Avail Dev Size : 7804374912 (3721.42 GiB 3995.84 GB)
     Array Size : 3902187456 (3721.42 GiB 3995.84 GB)
    Data Offset : 2048 sectors
   Super Offset : 8 sectors
   Unused Space : before=1968 sectors, after=0 sectors
          State : clean
    Device UUID : f438ba9a:de56a419:8b37175f:571da70e

    Update Time : Tue Feb 21 16:45:43 2017
       Checksum : a212c9d2 - correct
         Events : 2


   Device Role : Active device 0
   Array State : AA ('A' == active, '.' == missing, 'R' == replacing)
mdadm --detail --scan
INACTIVE-ARRAY /dev/md127 metadata=1.2 name=DiskStation:2 UUID=ea184280:8651a5e3:3b29dee4:c957cc20
cat /proc/mdstat
Personalities :
md127 : inactive sdb5[0](S)
      3902187456 blocks super 1.2

unused devices: <none>

2. mount

mdadm --stop /dev/md127
mdadm: stopped /dev/md127
mdadm: Cannot get exclusive access to /dev/md127:Perhaps a running process, mounted filesystem or active volume group?
vgchange -a n vg1000
mdadm --assemble --scan
mdadm: /dev/md/DiskStation:2 has been started with 1 drive (out of 2).
vgscan
  Reading volume groups from cache.
  Found volume group "vg1000" using metadata type lvm2
  Found volume group "v01" using metadata type lvm2
mount /dev/mapper/vg1000-lv /mnt/everest/