Gave up waiting for root device. Unable to launch VM's properly??

asked 2018-02-09 06:56:19 -0500

vathanlal gravatar image

updated 2018-02-12 09:58:33 -0500

Hello, In my OpenStack cluster I was able to launch VM's successfully until 2 days before. But yesterday onward Iam able to launch the VM's and is showing me active status. But iam not able to ssh into the newly launched VM's. I looked into all possible logs related to OpenStack and but I didnt find any errors. Then I checked the console log of the launched ubuntu VM's and I saw the errors as below.

 Begin: Running /scripts/local-block ... mdadm: CREATE group disk not found
    mdadm: No devices listed in conf file were found.
    done.
    done.
    Gave up waiting for root device.  Common problems:
     - Boot args (cat /proc/cmdline)
       - Check rootdelay= (did the system wait long enough?)
       - Check root= (did the system wait for the right device?)
     - Missing modules (cat /proc/modules; ls /dev)
    ALERT!  LABEL=cloudimg-rootfs does not exist.  Dropping to a shell!


    BusyBox v1.22.1 (Ubuntu 1:1.22.0-15ubuntu1) built-in shell (ash)
    Enter 'help' for a list of built-in commands.

    (initramfs) [6n

Iam not sure what could be the possible reason for this and how to solve this. Any information is really appreciated. Detail log when I use "nova console-log 736878e8-29c6-4ef0-8907-44b02b1b0ced" is as below

 [    6.496505]    avx       :  7652.000 MB/sec
    [    6.500568] async_tx: api initialized (async)
    [    6.519511] md: raid6 personality registered for level 6
    [    6.521283] md: raid5 personality registered for level 5
    [    6.523020] md: raid4 personality registered for level 4
    [    6.532680] md: raid10 personality registered for level 10
    done.
    Begin: Running /scripts/init-premount ... done.
    Begin: Mounting root file system ... Begin: Running /scripts/local-top ... done.
    Begin: Running /scripts/local-premount ... [    6.588774] Btrfs loaded
    Scanning for Btrfs filesystems
    done.
    Begin: Waiting for root file system ... Begin: Running /scripts/local-block ... mdadm: CREATE group disk not found
    mdadm: No devices listed in conf file were found.
    done.
    Begin: Running /scripts/local-block ... mdadm: CREATE group disk not found
    mdadm: No devices listed in conf file were found.
    done.
    Begin: Running /scripts/local-block ... mdadm: CREATE group disk not found
    mdadm: No devices listed in conf file were found.
    done.
    Begin: Running /scripts/local-block ... mdadm: CREATE group disk not found
    mdadm: No devices listed in conf file were found.
    done.
    Begin: Running /scripts/local-block ... mdadm: CREATE group disk not found
    mdadm: No devices listed in conf file were found.
    done.
    Begin: Running /scripts/local-block ... mdadm: CREATE group disk not found
    mdadm: No devices listed in conf file were found.
    mdadm: CREATE group disk not found
    mdadm: error opening /dev/md?*: No such file or directory
    mdadm: CREATE group disk not found
    mdadm: No devices listed in conf file were found.
    done.
    Begin: Running /scripts/local-block ... mdadm: CREATE group disk not found
    mdadm: No devices listed in conf file were found.
    done.
    Begin: Running /scripts/local-block ... mdadm: CREATE group disk not found
    mdadm: No devices listed in conf file were found.
    done.
    done.
    Gave up waiting for root device.  Common problems:
     - Boot args (cat /proc/cmdline)
       - Check rootdelay= (did the system wait long enough ...
(more)
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Comments

It seems that your VM/your image is configured with MD RAID for the root disk. To me, this makes no sense for a cloud server.

The VM also tries to find a disk labeled cloudimg-rootfs. At the initramfs prompt, check the content of fstab.

How did you start this instance? From which image?

Bernd Bausch gravatar imageBernd Bausch ( 2018-02-09 17:59:14 -0500 )edit

I used the ubunu xenial Image from https://docs.openstack.org/image-guid... I started the image from horizon dashboard and also from the cli without any volume parameter but same error. Question is updated please go through it.

vathanlal gravatar imagevathanlal ( 2018-02-12 02:47:52 -0500 )edit

Nova uses a Glance image metadata item hw_disk_busto determine virtio, SCSI etc.; see https://docs.openstack.org/python-gla....

Bernd Bausch gravatar imageBernd Bausch ( 2018-02-12 17:07:02 -0500 )edit

I am sure I am missing something, but can you access the interactive console? Something tells initramfs to assemble an MD array. A conf file is mentioned, probably /etc/mdadm.conf. Check the kernel command line for md. Does the disk have an MD superblock that confuses the initramfs program?

Bernd Bausch gravatar imageBernd Bausch ( 2018-02-12 17:18:13 -0500 )edit

If not the console, perhaps you find something snooping around on the disk /var/lib/nova/instances/b36b7e22-71e8-4c8e-ac2e-f6573a04dda0/disk.

Bernd Bausch gravatar imageBernd Bausch ( 2018-02-12 17:18:39 -0500 )edit