Hi I have a disk which two of the partitions are part of a RAID1 setup. I'm trying to rename the the second raided partition mdadm -E /dev/sdc4 /dev/sdc4: Magic : a92b4efc Version : 1.2 Feature Map : 0x1 Array UUID : 83d7657b:ebfddcb7:36b0fa14:d29a350c Name : oldname:2 Creation Time : Tue Aug 30 15:25:10 2016 Raid Level : raid1 Raid Devices : 2 Avail Dev Size : 486696960 (232.08 GiB 249.19 GB) Array Size : 243348480 (232.08 GiB 249.19 GB) Data Offset : 262144 sectors Super Offset : 8 sectors Unused Space : before=262056 sectors, after=0 sectors State : clean Device UUID : 97aba979:dd4cf85c:f6dbf4f6:f1e9ccab Internal Bitmap : 8 sectors from superblock Update Time : Fri Sep 23 14:21:00 2016 Bad Block Log : 512 entries available at offset 72 sectors Checksum : 749e26a8 - correct Events : 7319 Device Role : Active device 0 Array State : A. ('A' == active, '.' == missing, 'R' == replacing) For the first partition I stopped the RAID using mdadm --stop /dev/md127 and then reassembeld using mdadm --assemble /dev/md127 --name=newname_boot --update=name /dev/sdc2 The first partition was easy as the system had started the RAID, but the second parition the system does start, and when I try to assemble it, it tells me it's already active:- mdadm --assemble --uuid=83d7657b:ebfddcb7:36b0fa14:d29a350c --name=newname2 --update=name /dev/md2 /dev/sdc4 mdadm: Found some drive for an array that is already active: /dev/md/oldname:2 So any ideas on how i can rename this ? Thanks Phil.