Distributing the software upgrade files involves unpacking the software files and loading the new software. When you perform a distribution, the NIOS appliance loads the new software code into an alternate disk partition, which overwrites any previously saved version of code that is already there. Therefore, starting the distribution disables the appliance from reverting to a release prior to the current version.

The time this process takes depends on the number of appliances to which the software is distributed; the more appliances, the longer it takes. Therefore, you might want to schedule the Grid distribution to times when your network is less busy. You can distribute the software immediately or schedule the distribution of the software upgrade file.

The following are some operational guidelines for performing a distribution:

• You cannot create new upgrade groups, add members to a group, or remove members from a group after a distribution starts.

• You can skip a member that is currently offline from a distribution. When both nodes of an HA pair are online, the skip member function is not available.

• A Grid member that joins the Grid after the distribution phase does not get validated during the test upgrade phase.

Software Distribution Process

The following series of events occur after a Grid distribution starts:

• The appliance checks if a NIOS software upgrade was uploaded.

  • If the upgrade files are not uploaded, the distribution stops. The appliance displays an error message and if the distribution is scheduled, the appliance deactivates the distribution schedule.

  • If the upgrade files are uploaded, the distribution proceeds.

• The Grid Master uploads the file to a backup partition and unpacks the contents, which overwrite any existing backup software that might have been there. For an HA Grid Master, it is the active node that uploads the file to a backup partition and unpacks the contents.

  • The Grid Master (or active node of an HA Grid Master) sends a command to all nodes that are online to copy their database and software to a backup software partition.

  • For an HA Grid Master, the active node sends the command to the passive node as well.

  • The nodes perform resynchronization on their backup partition, retrieving only the changed files from the Grid Master.

  • After the active node of an HA member receives the software, it then distributes it to the passive node.

When the distribution successfully completes, the appliance updates the distribution status and sets the schedule, if configured, to inactive. The new software is now staged on all member appliances and is ready for use. Grid Manager displays the software version in the Distribution field in the Grid Version Information section.