Before Installing CentOS 7.2

The following considerations should be taken into account prior to installing CentOS 7.2

• If you want to preserve a workstation's installation of a previous version of the operating system, you must install CentOS 7.2 on a separate drive.
• It is recommended to disconnect all other disks - secondary drives, RAID disks, SAN volumes - before running the CentOS installer we provide.
• Some administrative commands have changed between CentOS 6 and CentOS 7. For a list of common administrative commands equivalencies between CentOS 6 and CentOS 7, see: Common Administrative Commands.
• There is an NFS incompatibility between CentOS 6/Red Hat and CentOS 7. Workstations on CentOS/RedHat 6.2 are unable to read data from a CentOS 7.2 workstation via NFS.
• If you use removable storage, it is strongly recommended to add the nofail argument to /etc/fstab. Without the nofail argument, the workstation will not boot if the removable storage is not present.
• The default filesystem format on CentOS 7.2 has changed. It is now XFS.
• If you use a Stornext SAN, you must be on filesystem version 5.3.1, to avoid compatibility issues.
• The Gnome Desktop environment does not work on CentOS 7.2. Flame Family products use the KDE environment by default.
• If using Infiniband on CentOS 7.2, make sure you are using it in Connected mode, as Datagram mode has performance issues. Going forward, this will be the default configuration for Flame Family products. In the Infiniband configuration file, make sure to add: CONNECTED_MODE=yes.
• If your /etc/exports file contains file paths that are no longer valid, the NFS service will be unable to start. Make sure the file only contains valid file paths.
• Multipath drivers are supported on CentOS 7.2, however the luns IDs must be reconfigured. To do this:
  1. From a shell, as root, cd to /opt/Autodesk/DKU/current/Utils/Storage/DH_Configurator_v1.12
  2. Run ./DH_config.sh -d.

     You are prompted for the drive's IP address. The default values are 10.0.0.2 for Controller A, and 10.0.0.3 for Controller B.

  3. Enter the IP address of the drive you want to configure (Controller A or B).
  4. Select Option 9 (Update luns ID) from the list of options.
  5. Reboot the workstation.