RAID-1 mirror has become a single hard disk

I have an HP N40L microserver, with 2 identical drives, I used the system to hardware-RAID them as a mirror. I then installed mint on the system about a year ago. This has been running perfectly, updating, etc. until I upgraded to Mint 17. I thought everything was fine, but I've noticed that mint is only using 1 of the drives to boot, then for some reason was showing the contents of the other drive. i.e. it boots sdb1, but df shows sda1. I'm *sure* df used to show a /dev/mapper/pdc_bejigbccdb1 drive which was the RAID array. Thus any updates to Grub go to sda1, but it boots sdb1 then loads the fs sda1. N40L marty # df Filesystem 1K-blocks Used Available Use% Mounted on /dev/sda1 233159608 113675036 107617644 52% / none 4 0 4 0% /sys/fs/cgroup /dev 2943932 12 2943920 1% /media/sda1/dev tmpfs 597588 1232 596356 1% /run none 5120 0 5120 0% /run/lock none 2987920 0 2987920 0% /run/shm none 102400 4 102396 1% /run/user From cat /etc/fstab N40L marty # cat /etc/fstab # /etc/fstab: static file system information. # # Use 'blkid' to print the universally unique identifier for a # device; this may be used with UUID= as a more robust way to name devices # that works even if disks are added and removed. See fstab(5). # # proc /proc proc nodev,noexec,nosuid 0 0 /dev/mapper/pdc_bejigbccdb1 / ext4 errors=remount-ro 0 1 /dev/mapper/pdc_bejigbccdb5 none swap sw 0 0 If I do ls /dev/mapper/ I get N40L marty # ls /dev/mapper total 0 crw------- 1 root root 10, 236 Jul 24 17:03 control How do I get my raid back and how do I get grub to boot to it? ---- Further update: N40L grub # dmraid -r /dev/sdb: pdc, "pdc_bejigbccdb", mirror, ok, 486328064 sectors, data@ 0 /dev/sda: pdc, "pdc_bejigbccdb", mirror, ok, 486328064 sectors, data@ 0 N40L grub # dmraid -s *** Set name : pdc_bejigbccdb size : 486328064 stride : 128 type : mirror status : ok subsets: 0 devs : 2 spares : 0 N40L grub # dmraid -ay -vvv -d WARN: locking /var/lock/dmraid/.lock NOTICE: /dev/sdb: asr discovering NOTICE: /dev/sdb: ddf1 discovering NOTICE: /dev/sdb: hpt37x discovering NOTICE: /dev/sdb: hpt45x discovering NOTICE: /dev/sdb: isw discovering DEBUG: not isw at 250059348992 DEBUG: isw trying hard coded -2115 offset. DEBUG: not isw at 250058267136 NOTICE: /dev/sdb: jmicron discovering NOTICE: /dev/sdb: lsi discovering NOTICE: /dev/sdb: nvidia discovering NOTICE: /dev/sdb: pdc discovering NOTICE: /dev/sdb: pdc metadata discovered NOTICE: /dev/sdb: sil discovering NOTICE: /dev/sdb: via discovering NOTICE: /dev/sda: asr discovering NOTICE: /dev/sda: ddf1 discovering NOTICE: /dev/sda: hpt37x discovering NOTICE: /dev/sda: hpt45x discovering NOTICE: /dev/sda: isw discovering DEBUG: not isw at 250059348992 DEBUG: isw trying hard coded -2115 offset. DEBUG: not isw at 250058267136 NOTICE: /dev/sda: jmicron discovering NOTICE: /dev/sda: lsi discovering NOTICE: /dev/sda: nvidia discovering NOTICE: /dev/sda: pdc discovering NOTICE: /dev/sda: pdc metadata discovered NOTICE: /dev/sda: sil discovering NOTICE: /dev/sda: via discovering DEBUG: _find_set: searching pdc_bejigbccdb DEBUG: _find_set: not found pdc_bejigbccdb DEBUG: _find_set: searching pdc_bejigbccdb DEBUG: _find_set: not found pdc_bejigbccdb NOTICE: added /dev/sdb to RAID set "pdc_bejigbccdb" DEBUG: _find_set: searching pdc_bejigbccdb DEBUG: _find_set: found pdc_bejigbccdb DEBUG: _find_set: searching pdc_bejigbccdb DEBUG: _find_set: found pdc_bejigbccdb NOTICE: added /dev/sda to RAID set "pdc_bejigbccdb" DEBUG: checking pdc device "/dev/sda" DEBUG: checking pdc device "/dev/sdb" DEBUG: set status of set "pdc_bejigbccdb" to 16 DEBUG: checking pdc device "/dev/sda" DEBUG: checking pdc device "/dev/sdb" DEBUG: set status of set "pdc_bejigbccdb" to 16 RAID set "pdc_bejigbccdb" was not activated WARN: unlocking /var/lock/dmraid/.lock DEBUG: freeing devices of RAID set "pdc_bejigbccdb" DEBUG: freeing device "pdc_bejigbccdb", path "/dev/sda" DEBUG: freeing device "pdc_bejigbccdb", path "/dev/sdb" So my system sees the two drives and sees they should be part of an array, but will not activate the array and this not create /dev/mapper/pdc_bejigbccdb so I cannot load grub to it and boot from it. How do I get dmraid to activate and create the mapper entry?