$ sudo mdadm --detail /dev/md0
/dev/md0:
           Version : 1.2
     Creation Time : Sat Jan  9 15:52:00 2021
        Raid Level : raid1
        Array Size : 244065408 (232.76 GiB 249.92 GB)
     Used Dev Size : 244065408 (232.76 GiB 249.92 GB)
      Raid Devices : 2
     Total Devices : 2
       Persistence : Superblock is persistent
     Intent Bitmap : Internal
       Update Time : Sat Jan  9 15:52:21 2021
             State : clean, resyncing
    Active Devices : 2
   Working Devices : 2
    Failed Devices : 0
     Spare Devices : 0
Consistency Policy : bitmap
     Resync Status : 1% complete
              Name : dev-machine:0  (local to host dev-machine)
              UUID : 833033c5:cd9b78de:992202ee:cb1bf77f
            Events : 4
    Number   Major   Minor   RaidDevice State
       0     259        2        0      active sync   /dev/nvme0n1p1
       1       8       33        1      active sync writemostly   /dev/sdc1