compaction
1) In a data center, compaction is the reduction or consolidation of hardware to make better use of physical floor space. Although the goal of compaction is to be cost-effective and maximize real estate, increased hardware compaction puts more demands on power consumption and cooling requirements, two major cost elements in maintaining a large data center.
2) In storage area management (SAM), compaction is the automatic removal of expired data from a storage area network (SAN) to condense the existing archive and make room for new data.