Last week, Data Domain announced the highest performance inline deduplication system in the industry with the DD690. EMC and Quantum followed hastily with their own announcements.
Nothing has changed
EMC is repacking the Quantum 7500 in the EMC DL3D line. But the inline dedupe rate is still about 150 MB/sec., according to this discussion, after which the only rates we can know for sure are to and from their non-dedupe cache. So the effective capacity, the amount you can dedupe in a backup day, is something less than 13 TBs (dedupe rate x 24 hours). If you don't finish deduping in a day, it will compromise tomorrow's throughput and backup window. So the only way you could use 150 TB of this disk for dedupe is if your backup window is more than two weeks long.
Why offer 148-180 TB in this architecture? Because it is not a dedupe system, it is a traditional VTL (even if it has a NAS interface) -- a disk-based, short-term-retention I/O buffer for data on the way to tape. The extra storage baggage? Call that dupestorage. It is not meaningful for sizing dedupe or replication. Data Domain's dedupe speed and resulting effective capacity is greated by more than a factor of two.
Seems like everything's still the same:
- Data Domain is still the deduplication performance leader;
- EMC and Quantum are still selling traditional VTLs based on dedupe storage;
- EMC is still selling massively over-provisioned disk systems;
- Quantum is really trying to sell tape libraries above all.
Oh, I guess one thing has changed. Inline deduplication used to be considered too slow compared to a post-process. I guess that has changed. The non-dedupe write speed of the EMC DL3D 3000, at 1.44 TB/hour, s about the same as the inline dedupe speed of the DD690. If post-process isn't even faster than inline, why bother?
