RAID 1 problem on boot disk

[daveboulter42]

Hi,

I have managed to build a new Centos server on a HPE DL120G9 platform. It has 2 x 2TB drives for OS and 2 x 4TB drives for data. All drives are SATA. To test the RAID1 I took the first drive out and server did not boot. Obviously as per below, I think. It looks like sdb has not mirrored sda. How can I fix this without having to rebuild from scratch again?

[xxxxx@xxxxxsvr ~]$ lsblk
NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT
sda 8:0 0 1.8T 0 disk
├─sda1 8:1 0 200M 0 part /boot/efi
├─sda2 8:2 0 1G 0 part /boot
└─sda3 8:3 0 1.8T 0 part
└─md127 9:127 0 1.8T 0 raid1
├─centos-root 253:0 0 50G 0 lvm /
├─centos-swap 253:1 0 7.6G 0 lvm [SWAP]
└─centos-home 253:2 0 1.8T 0 lvm /home
sdb 8:16 0 1.8T 0 disk
└─sdb1 8:17 0 1.8T 0 part
sdc 8:32 0 3.7T 0 disk
└─md1 9:1 0 3.7T 0 raid1
└─md1p1 259:0 0 3.7T 0 md /data
sdd 8:48 0 3.7T 0 disk
└─md1 9:1 0 3.7T 0 raid1
└─md1p1 259:0 0 3.7T 0 md /data
[xxxxx@xxxxxsvr ~]$

[daveboulter42]

and output from mdadm:

[xxx@xxxsvr ~]$ sudo mdadm --verbose --detail -scan
[sudo] password for tradmin:
ARRAY /dev/md/pv00 level=raid1 num-devices=2 metadata=1.2 name=emmwebsvr.localdomain:pv00 UUID=35a6134a:f063b925:f090dfcd:aacd6da7
devices=/dev/sda3
ARRAY /dev/md/1 level=raid1 num-devices=2 metadata=1.2 name=emmwebsvr.localdomain:1 UUID=a1a25608:f34aad67:44db7ef4:7c4771fe
devices=/dev/sdc,/dev/sdd
[xxx@xxxsvrsvr ~]$