Review: Exablox OneBlox is a storage admin's dream

Network-attached storage servers typically offer similar feature sets, and they often deliver similar performance. RAID levels, networking protocols, and many hardware features are standard by nature, leaving little room for innovation in the NAS realm.

Exablox takes a different tack. Rather than compete directly on features and speed, Exablox focuses on simplifying scalability and data redundancy. The result is innovation rarely seen in a storage appliance.

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From a hardware standpoint, the Exablox OneBlox closely resembles other storage devices. A three-inch LCD on the front panel displays basic configuration information such as the management URL, hostname, public IP address, and the name of the OneBlox ring it has joined (more on that below). When this panel is flipped down, it reveals eight 3.5-inch drive bays, which support any combination of SATA or SAS drives. LEDs representing each drive bay show basic health information for each disk. The rear of the OneBlox features a standard power connector, power switch, and four Gigabit Ethernet ports, which automatically bond to the same IP address. The appliance is stackable and supports rack mounting.

OneBlox does include a few nice hardware features. For example, the OneBlox accelerates file access by storing the file index on an SSD. Likewise, a dedicated hardware encryption chip is included to create SHA-1 file hashes for the index and to encrypt the files themselves using AES-256 for data protection. The dedicated hardware allows the OneBlox to perform encryption, compression, and deduplication with minimal overhead.

Despite the apparent similarities, the OneBlox is not your typical NAS. First off, the OneBlox offers support for only the CIFS and SMB protocols -- no iSCSI or NFS to be found here. And whereas users would typically choose a RAID level appropriate for their use case, the OneBlox requires no such configuration. Instead, the OneBlox uses an object-based storage system. The use of object storage allows the OneBlox to provide inline, object-level data deduplication and forms the basis of the scalability and data protection advantages offered by the solution. 

Objects, rings, and meshes
By using an object-based file system, Exablox is able to keep duplicate data to a minimum, distribute copies of files for data protection, and offer dynamic scalability on multiple levels. First, more hard drives can be added to a OneBlox appliance while it is online, and files will be automatically distributed across the new drive as needed to maintain redundancy. Second, when other OneBlox appliances are brought online, the extra storage space is automatically integrated into what appears to users as a single, contiguous volume.

Exablox uses the concept of rings to scale up storage capacity as you increase the number of appliances. When you deploy a OneBlox, you add it to a ring. OneBlox units that form a ring will automatically pass data back and forth in order to ensure that redundant copies of files exist elsewhere in the event of a hardware failure. Up to six OneBlox appliances can comprise a single ring, and they don't have to be homogenous -- the amount and type of storage used can vary wildly across units. A ring appears to other computers on the network as a single entity, even sharing the same hostname and IP address.