Network Appliance’s latest virtual tape library (VTL) appliances offer compression and high performance, but the company is holding off on adding data de-duplicationuntil it can do so without affecting performance.
Virtual tape “needs to be really, really fast to get the backups done,” says Krish Padmanabhan, general manager of NetApp’s heterogeneous data protection business unit. “We’re working on de-duplication, but we won’t compromise performance.” He expects NetApp to add the technology over the next year.
With the help of technology it acquired from Alacritus, Padmanabhan said NetApp’s new NearStore offerings boast a simpler architecture than competitors, with tighter tape library integration.
NetApp says the new NearStore VTL300, VTL700 and VTL1400 use compression to double or triple the amount of backup data that can be stored on disk while also increasing VTL write performance by more than 50 percent over their predecessors, the VTL600 and VTL1200.
With 2-to-1 hardware compression enabled, the VTL700 and VTL1400 deliver sustained write performance of 850 and 1700MB/sec, respectively. Padmanabhan said competitors such as Diligent and Data Domain offering de-duplication can see performance slow to less than 100MB/sec. However, de-duplication offers a much greater compression ratio of about 20-to-1.
Enterprise Strategy Group analyst Heidi Biggar said that by doing compression in hardware instead of software, “NetApp not only avoids the common performance pitfalls that go along with software compression — which often causes users to not compress data — but it also gets a significant performance boost, since fewer bits are being moved to disk. It’s a win-win situation for NetApp and, importantly, for users: reduced capacity requirements and better performance.”
NetApp’s approach was also tried by now-defunct Neartek, said Biggar, but most other vendors use software-based compression — although some of those competitors also offer de-duplication.
“So all in all, for end users — particularly higher-end customers where NetApp VTL is focused — hardware compression is a big deal not only because of the capacity reduction, but because of the performance advantage,” said Biggar. “When NetApp adds data de-dupe, they’ll have an even more compelling solution for the enterprise.”
The 500MB/sec VTL300 lists for $99,000 and can scale from 10TB to 53TB. The VTL700 lists for $154,000 and can scale from 10TB to 128TB, while the dual-head VTL1400 lists for $238,000 and scales from 20TB to 256TB.
Jim Lyons, product marketing manager for NearStore VTL, said the VTL600 and 1200 will continue to be supported, but he expects NetApp customers to upgrade to the new models.