static private String computePartitions(int redundancyPerGroup, int numGroups) {
            StringBuilder sb = new StringBuilder();
            for (int i = 0; i < numGroups - 1; ++i) {
                sb.append(redundancyPerGroup);
                sb.append("|");
            }
            sb.append("*");
            return sb.toString();
        }
This returns a partition string which specifies equal distribution between all groups
config-model/src/main/java/com/yahoo/vespa/model/content/StorageGroup.java