[SOLVED] Boot failed when migrate system from single disk to raid1

Issue

Basically, I try to migrate a single disk linux system(Centos7) to raid1, refer to this link page: LVM Single Drive to LVM RAID 1 Mirror Migration

But it's failed when I reboot the second, the system enter dracut mode and I got some message by journalctl:

dracut-initqueue[305]: Warnging: dracut-initqueue timeout - starting timeout scripts
dracut-initqueue[305]: Warnging: Could not boot.
dracut-initqueue[305]: Warnging: /dev/mapper/rootvg-root does not exist
dracut-initqueue[305]: Warnging: /dev/rootvg/root does not exist
dracut-initqueue[305]: Warnging: /dev/rootvg/swap does not exist

All steps can summarized into two point, migrate /dev/sda1(/boot) to /dev/md0 and migrate /dev/sda2(lvm) to /dev/md1, here is my partitions before migrate /dev/sda2:

[root@~]# lsblk
NAME                MAJ:MIN RM   SIZE RO TYPE  MOUNTPOINT
sda                   8:0    0    50G  0 disk
├─sda1                8:1    0   500M  0 part
│ └─md0               9:0    0 499.7M  0 raid1 /boot
└─sda2                8:2    0  49.5G  0 part
  ├─rootvg-root   253:0    0  29.3G  0 lvm   /
  ├─rootvg-swap   253:1    0   3.9G  0 lvm   [SWAP]
  └─rootvg-docker 253:2    0   9.8G  0 lvm   /var/lib/docker
sdb                   8:16   0    50G  0 disk
├─sdb1                8:17   0   500M  0 part
│ └─md0               9:0    0 499.7M  0 raid1 /boot
└─sdb2                8:18   0  49.5G  0 part
  └─md1               9:1    0  49.5G  0 raid1

Exactly, the issue is happened after move lvm partitions to raid1, I make sure the system can boot after add /dev/sda1 to the first raid1 array /dev/md0.

So when I use pvmove, vgreduce and pvremove migrate /dev/sda2 to /dev/md1, the system can not boot (nomatter add /dev/sda2 to /dev/md1 or not)

I searched a lot and promise I'm not forget execute dracut(instead of mkinitrd) to generate initramfs, but I'm also concerned about if the arguments is incorrect, here is:

dracut --mdadmconf --lvmconf --fstab --add-drivers "raid1" --filesystems "ext4 xfs" --force /boot/initramfs-$(uname -r).img $(uname -r)
grub2-mkconfig -o /boot/grub2/grub.cfg
grub2-install /dev/sda
grub2-install /dev/sdb

Thanks in advance:)

Solution

Finally I found the answer: We have to change /etc/default/grub and add rd.md.uuid before we exec grub2-mkconfig to update our grub configuration file. that will help us make raid array at grub step when system boot, then also your system can rightly identify the lvm, everything is ok.

I test it on Centos7, it works.

Answered By - Mer