I would like to know how mdadm identifies physical disks of raid1 .
I think it is managed by uuids not device file like /dev/sdc2 /dev/sdd2.
But I can`t confirm such information of raid1.
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Each Linux RAID volume (RAID-1 or otherwise) contains a superblock which, amongst other things, contains a UUID that is common between all the physical volumes underlying one array, and which is different from the UUID of any other array. For dissymmetric RAID arrangements (i.e. all but RAID-1), the volumes also contain information that tell