md: Autodetecting RAID arrays.
md: autorun ...
md: considering sdb1 ...
md: adding sdb1 ...
md: adding sda1 ...
md: created md0
md: bind<sda1>
md: bind<sdb1>
md: running: <sdb1><sda1>
md: kicking non-fresh sda1 from array!
md: unbind<sda1>
md: export_rdev(sda1)
raid1: raid set md0 active with 1 out of 2 mirrors
The md0 raid kicked sda1 out because either I never synced it before rebooting or it was "halted" because md1 was rebuilding.
mdadm --manage /dev/md0 --add /dev/sda1
After it syncs you'll see it shows both disks as active and up:
md0 : active raid1 sdb1[0] sda1[1]
307202816 blocks [2/2] [UU]
As you can see below, md1 was just fine:
md: autorun ...
md: considering sda1 ...
md: adding sda1 ...
md: md0 already running, cannot run sda1
md: export_rdev(sda1)
md: ... autorun DONE.
md: md1 stopped.
md: bind<sda2>
md: bind<sdb2>
raid1: raid set md1 active with 2 out of 2 mirrors
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