Unable to boot the server configured with mdraid for /boot and root filesystems

Solution Verified - Updated -


  • We have a system which is configured to use mdraid devices for /boot and root filesystem, but after recent patching activity it started to fail in boot process. The console logs during boot process showed following errors before failure in boot process:

    [   10.192497] testhost1 systemd-udevd[925]: starting '/sbin/mdadm  -I /dev/sdm2'
    [   10.194130] testhost1 systemd-udevd[643]: '/sbin/mdadm  -I /dev/sdm1'(err) 'mdadm: we match both /dev/md/boot and /dev/md/boot - cannot decide which to use.'
    [   10.194665] testhost1 systemd-udevd[643]: '/sbin/mdadm  -I /dev/sdm1' [924] exit with return code 2
    [   10.195528] testhost1 systemd-udevd[644]: '/sbin/mdadm  -I /dev/sdm2'(err) 'mdadm: we match both /dev/md/rootvg and /dev/md/rootvg - cannot decide which to use.'
    [   10.196089] testhost1 systemd-udevd[644]: '/sbin/mdadm  -I /dev/sdm2' [925] exit with return code 2

    Below is the mdraid configuration used on server:

    $ cat  /etc/mdadm.conf 
    # mdadm.conf written out by anaconda
    MAILADDR root
    AUTO +imsm +1.x -all
    ARRAY /dev/md/boot level=raid1 num-devices=2 UUID=123456789:c001dee1:457829631:1d1cb1e1
    ARRAY /dev/md/rootvg level=raid1 num-devices=2 UUID=54a54ds6:554d54saa:da454s5ad:1d1cb222
    ARRAY /dev/md/boot  metadata=1.0 UUID=123456789:c001dee1:457829631:1d1cb1e1 name=testhost1:boot
    ARRAY /dev/md/rootvg  metadata=1.2 UUID=54a54ds6:554d54saa:da454s5ad:1d1cb222 name=testhost1:rootvg

    Once the boot process was failed and control was left at dracut prompt, we are able to activate the mdraid devices manually and start the system.


  • Red Hat Enterprise Linux 7.4
  • mdraid devices used for /boot and root

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