How best to re-sync raid1 array? zero superblock on removed disk and let it rebuild?

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All,

I had a disc-controller failure on a server running several raid1 arrays. The disks are fine, but I have had the root partition come up in degraded mode. What is the best way to tell mdraid to resync the disks? Here are the symptoms:

# cat /proc/mdstat
Personalities : [raid1]
md1 : active raid1 sdb7[1]
      52396032 blocks super 1.2 [2/1] [_U]

md3 : active raid1 sdb6[1] sda6[0]
      1047552 blocks super 1.2 [2/2] [UU]

md2 : active raid1 sda8[0] sdb8[1]
      922944192 blocks super 1.2 [2/2] [UU]
      bitmap: 0/7 pages [0KB], 65536KB chunk

md0 : active raid1 sda5[0] sdb5[1]
      204608 blocks super 1.2 [2/2] [UU]

unused devices: <none>

# mdadm --misc --detail /dev/md1
/dev/md1:
        Version : 1.2
  Creation Time : Wed Nov 27 04:35:49 2013
     Raid Level : raid1
     Array Size : 52396032 (49.97 GiB 53.65 GB)
  Used Dev Size : 52396032 (49.97 GiB 53.65 GB)
   Raid Devices : 2
  Total Devices : 1
    Persistence : Superblock is persistent

    Update Time : Fri Aug 28 04:12:18 2015
          State : clean, degraded
 Active Devices : 1
Working Devices : 1
 Failed Devices : 0
  Spare Devices : 0

           Name : archiso:1
           UUID : 320d86f7:22999af5:5eeefee1:35cd8970
         Events : 100308

    Number   Major   Minor   RaidDevice State
       0       0        0        0      removed
       1       8       23        1      active sync   /dev/sdb7

Reading, it looks like one approach is the boot the install media and then zero the superblock on /dev/sda7 and then reboot. Will that force a rebuild, or do I need to fail and remove the disk first? I was thinking:

# mdadm --zero-superblock /dev/sda7

should set it up for a rebuild without more. Is this a sane approach?

--
David C. Rankin, J.D.,P.E.
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