Irreverence

posted on 30 July 2008 05:14

Speculation and expectations about a refreshed and deduplicating NetApp VTL (Virtual Tape Library) line are coalescing around an August announcement.

NetApp's VTL line has three members: VTL300 storing 70GB; VTL700 storing 336GB; and VTL1400 storing 672GB. The number is the number of SATA disk drives supported. Unlike other NetApp storage systems the VTL line runs the Linux-based NetApp VTL OS and not Data ONTAP, its platform OS.

The line was refreshed in a major way in October 2006. It features hardware compression but not deduplication. The hardware compression provides a 2:1 data reduction and NetApp has mentioned that the VTL's could have a 20:1 deduplication ratio over time with compression doubling that.

NetApp says that the VTL OS is a totally NetApp-owned technology. Its Data ONTAP OS has A-SIS sub-file-level deduplication. The expectation is that some or all of this technology will be ported to VTL OS.

Competing VTLs typically have a deduplicating capability; for example, Data Domain and Overland Storage products, Quantum's DXi7500, and the EMC DL3D product line.

Typically NetApp provides a significant hardware refresh of its products every 18 months or so. A 2006 presentation deck from the company mentions that the VTL OS provides a VTL personality for its FAS hardware.

In June the FAS3000 line was upgraded with dual-core CPUs and additional RAM in the controllers.

If NetApp were to add inline deduplication, which operates as data is ingested, then more powerful CPUs would be needed compared to post-ingestion dedupe, in order to reduce the backup time. Data Domain provides inline deduplication and both EMC and Quantum offer this as an option.

Post-ingestion dedupe requires less disk space to hold incoming and undeduplicated data and offers the fastest backup time. A-SIS is a post-ingestion deduplication process.

NetApp says it has more than 2,500 customers with 10,000 systems in the field using its A-SIS deduplication.

^{[Chris Mellor.]}