Plasmon's UDO2 is a second-generation Ultra-Density Optical (UDO) archive, which doubles its storage capacity from 30 to 60 GB. All UDO products are backward compatible, eliminating the need to migrate data. The UDO Archive Appliance is a network-attached archiving system, or a plug-n-play ‘library,’ increasing its storage space from 32 pieces of media to 638.