On 07/25/2014 06:56 AM, Robert Nichols wrote: > Unless you can figure out some way to move the start of the partition back > to make room for the RAID superblock ahead of the existing filesystem, the > answer is, "No." The version 1.2 superblock is located 4KB from the start > of the device (partition) and is typically 1024 bytes long. > > https://raid.wiki.kernel.org/index.php/RAID_superblock_formats Sadly, this is probably the authoritative answer I was hoping not to get. It would seem technically quite feasible to reshuffle the partition a bit to make this happen with a special tool (perhaps offline for a bit - you'd only have to manage something less than a single MB of data) but I'm guessing nobody has "felt the itch" to make such a tool. On 07/25/2014 08:10 AM, Les Mikesell wrote: > What happens if you mount the partition of a raid1 member directly > instead of the md device? I've only done that read-only, but it does > seen to work. > As I originally stated, I've done this successfully many times with a command like: mount -t ext{2,3,4} /dev/sdXY /media/temp -o rw Recently, it seems that RHEL/CentOS is smart enough to automagically create /dev/mdX when inserting a drive "hot" EG: USB or hot swap SATA, so I haven't had to do this for a while. You can, however do this, which seems to be logically equivalent: mdadm --manage /dev/mdX --stop; mount -t ext{2,3,4} /dev/sdXY /media/temp -o rw; -Ben