This reference states that class of service is supported in a logical system, but another reference disagrees. This may be a disparity between versions, but I have notoiced there is no class of service stanza in a logical system on 12.3. Does the global CoS config apply to logical systems; will the following work as imagined?
set logical-systems prod interfaces ge-1/1/1 unit 0
set class-of-service interfaces ge-1/1/1 unit 0 rewrite-rules dscp default