I'm not sure why, but after I restarted my ec2 instance, /dev/md0 didn't start as it normally would. after I saw what's available in /dev/md*, instead of seeing /dev/md0, there is a device there named /dev/md127. I updated fstab to reflect the new device and was able to mount it successfully. Looking at /proc/mdstat, it is using the correct underlying ephemeral volumes that the RAID was originally created on:
[root@ip-10-0-1-21 ~]# cat /proc/mdstat Personalities : [raid0] md127 : active raid0 xvdc1 xvdb1 870336512 blocks super 1.2 512k chunks unused devices: <none>
Yet when I run a
mdadm --detail --scan a difference device name shows up:
[root@ip-10-0-1-21 ~]# mdadm --detail --scan ARRAY /dev/md/ip-10-0-1-21:0 metadata=1.2 name=ip-10-0-1-21:0 UUID=543098de:1e9dc96e:4ce2444c:934bdfdf
Is it normal for the device name to change? Do I have to update /etc/fstab with the new device name? Is it critical that I re-run /etc/mdadm.conf with the new information? Is this device name /dev/md127 or dev/md/ip-10-0-1-21:0? I suppose I'm not sure what's going on here. Some insight would be great.