vSphere Data Protection fails to boot due to MCS service failing to start
search cancel

vSphere Data Protection fails to boot due to MCS service failing to start


Article ID: 326789


Updated On:


VMware vSphere ESXi



  • vSphere Data Protection fails during the boot process.
  • Manually starting the MCS service fails.
  • Running the command dpnctl status all returns similar to:

    Identity added: /home/dpn/.ssh/dpnid (/home/dpn/.ssh/dpnid)
    dpnctl: INFO: gsan status: up
    dpnctl: INFO: MCS status: down.
    dpnctl: INFO: Backup scheduler status: down.
    dpnctl: INFO: axionfs status: down.
    dpnctl: INFO: Maintenance windows scheduler status: enabled.
    dpnctl: INFO: Unattended startup status: enabled.
    dpnctl: INFO: [see log file "/usr/local/avamar/var/log/dpnctl.log"]

  • In the var/log/vmkernel file you see an entry similar to:

    == BEGIN === check.mcs (prestart)
    ERROR: check.mcs: [vdp_fqdn] checking if localhost is correctly defined in /etc/hosts CHECK FAILED: localhost entry for IPv4 and IPv6 networks not found in /etc/hosts.
    - - - - - - - - - - - - - - - END


This issue occcurs due to the /etc/hosts not properly creating a local loop entry


To resolve this issue, modify the /etc/hosts file to have the correct loopback entry.
  1. Connect to the VMware Data Appliance with an SSH session using root credentials.
  2. Open the /etc/hosts file with a text editor using this command:

    vi /etc/hosts

    Example output:
    # Generated by av_boot.rb
    # this file is generated by dpnnetutil, it will be overwritten vdpserver.domain.com vdpserver
    ## vdpserver.domain.com vdpserver vdpserver
    ##::1 vdpserver.domain.com vdpserver localhost ip6-localhost ip6-loopback
  3. Edit the and ::1 lines to this: localhost.localdomain localhost
    ::1 localhost ipv6-localhost ipv6-loopback

  4. Save changes to the file and exit
  5. Start the MCS service with this command:

    dpnctl start mcs

Additional Information

MCS サービスが起動できないため、vSphere Data Protection が起動に失敗する
由于启动 MCS 服务失败,无法引导 vSphere Data Protection