Space-optimized snapshots do not contain complete physical images of the original data objects they represent. Space-optimized instant snapshots record changed regions in the original volume to a storage cache. As the original volume is written to, VxVM preserves its data in the cache before the write is committed. As the storage cache typically requires much less storage than the original volume, it is referred to as space-optimized. Space-optimized snapshots consume storage and I/O bandwidth in proportion to how much data on the original volume is updated during the life of the snapshot.

The benefits of space-optimized instant snapshots include immediate availability for use, quick refreshment, and easier configuration and administration. Because space-optimized snapshots consume less storage and I/O bandwidth than full-copy snapshots, you can take the snapshots much more frequently. This makes them well-suited for recovering from data corruption.

Space-optimized snapshots naturally tend to grow with age, as more of the data in the original objects changes, so they are inherently better-suited for shorter lifetimes.

Space-optimized snapshots cannot be taken off-host for auxiliary processing.