Verifying candidate host resources

Use this procedure to determine whether the hardware resources and installed operating system of a host are sufficient to serve as a Control Center master host.
  1. Log in to the candidate host as root, or as a user with superuser privileges.
  2. Verify that the host implements the 64-bit version of the x86 instruction set.
    uname -m
    • If the output is x86_64, the architecture is 64-bit. Proceed to the next step
    • If the output is i386/i486/i586/i686, the architecture is 32-bit. Stop this procedure and select a different host.
  3. Verify that the host has adequate storage space for Docker temporary files and audit logging.
    1. Display the amount of space available in /tmp.
      Docker requires 10GB of storage for temporary files, and the installation process includes instructions to link the Docker temporary directory to /tmp.
      df -h /tmp
      Typically, /tmp is mounted on the root filesystem, /.
    2. Display the amount of space available in /var/log.
      By default, Control Center requires 10GB of space for audit logging in /var/log. The amount of space required for audit logs, and their location, is configurable. For more information, refer to the Control Center Reference Guide.
      df -h /var/log
      Like /tmp, /var/log is typically mounted on the root filesystem, /.
    If the result does not include a minimum of 10GB of space for Docker temporary files and 10GB for audit logging, stop this procedure and select a different host.
  4. Determine whether the available memory and swap is sufficient.
    1. Display the available memory.
      free -h
    2. Compare the available memory and swap space with the amount required for a master host in your deployment.
      For more information, refer to the Control Center Planning Guide.
    If the result does not meet minimum requirements, stop this procedure and select a different host.
  5. Determine whether the CPU resources are sufficient.
    1. Display the total number of CPU cores.
      cat /proc/cpuinfo | grep -Ec '^core id'
    2. Compare the available resources with the requirements for a Control Center master host.
      For more information, refer to the Control Center Planning Guide.
  6. Determine whether the CPU resources support the AES instruction set.
    cat /proc/cpuinfo | grep -Ec '^flags.*aes'
    For optimal performance, the result of the preceding commands must match the total number of CPU resources available on the host. If the result is 0, performance is severely degraded.

    If the result is 0 and the candidate host is a virtual machine, the managing hypervisor may be configured in Hyper-V compatibility mode. Check the setting and disable it, if possible, or select a different host.

  7. Determine whether the installed operating system release is one of the releases that has been tested with Control Center.
    cat /etc/redhat-release
    • If the result includes 7.2, 7.3, or 7.4 proceed to the next step.
    • If the result does not include 7.2, 7.3, or 7.4, select a different host, and then start this procedure again.
  8. Ensure the host has a persistent numeric ID.
    Skip this step if you are installing a single-host deployment.
    Each Control Center host must have a unique host ID, and the ID must be persistent (not change when the host reboots).
    test -f /etc/hostid || genhostid ; hostid
    Record the ID for comparison with other Control Center hosts.
  9. Verify that name resolution works on this host.
    hostname -i
    If the result is not a valid IPv4 address, add an entry for the host to the network nameserver, or to /etc/hosts.
  10. Add an entry to /etc/hosts for localhost, if necessary.
    1. Determine whether 127.0.0.1 is mapped to localhost.
      grep 127.0.0.1 /etc/hosts | grep localhost
      If the preceding commands return no result, perform the following substep.
    2. Add an entry to /etc/hosts for localhost.
      echo "127.0.0.1 localhost" >> /etc/hosts
  11. Update the Linux kernel, if necessary.
    1. Determine which kernel version is installed.
      uname -r
      If the result is lower than 3.10.0-327.22.2.el7.x86_64, perform the following substep.
    2. Update the kernel, and then restart the host.
      The following commands require internet access or a local mirror of operating system packages.
      yum makecache fast && yum update kernel && reboot