While Exablox describes its object-based OneBlox appliance as a production storage system, many of its customers use it for backup. This week the vendor added a useful backup feature – variable-length deduplication.
Variable-length deduplication is an alternative to fixed-length deduplication. Variable-length dedupe breaks a file system into chunks of various sizes while fixed-length breaks all files into chunks that are the same size. Because it can use smaller chunks, variable length dedupe can get better reduction ratios.
Exablox senior director of products Sean Derrington said he expects a backup on OneBlox with variable-length dedupe to typically provide a 10:1 ratio compared to 3:1 for fixed length.
EMC’s Data Domain and Avamar, and Quantum DXi disk backup systems also use variable block dedupe.
Exablox storage is object based, but users access data through an NFS or SMB file share. All of its dedupe and compression occur inline, and it also supports continuous snapshots and replication between boxes.
Exablox supported fixed-length dedupe on OneBlox from the start. Derrington said he expects some customers will still use fixed-length for primary storage but variable-block will be the more popular option for backup. Customers can use fixed- length and variable-length for different applications inside the same storage pool.
“For any applications that they’re storing on OneBlox, customers can define storage policies on a per share basis or application basis,” Derrington said. “They can decide if they want fixed-length or variable-length dedupe, if they want compression on or off, snapshots on or off, or remote replication on or off. They can use fixed-length dedupe because it’s better suited for primary data and turn compression off on videos or images because they don’t compress well. They can turn snapshots off if the application does [snapshots].”
Derrington said a customer using fixed-length dedupe now can switch to variable-length, and get the full benefit of the better ratios after the current retention period passes. “If they have a 14-day retention period, on Day 15 all the data that’s been backed is on variable-length dedupe,” he said.
Tim Stammers, a senior analyst at 451 Research, said Exablox offers “simple cheap and deep storage” with a twist. “It’s unusual to have native NFS and SMB on an object box,” he said. “Exablox supports existing apps and leaves you with object storage underneath.”
Exablox also added an on-premise option for managing OneBlox appliances. Private OneSystem proactively monitors and identifies potential problems. It is deployed as a virtual machine inside a customers’ data center. From the start, Exablox used a cloud-based OneSystem for storage management. Now customers can choose between on-prem and cloud management.