Nasuni Filer

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A Virtual NAS Appliance: The Cloud in a Familiar Package

To deliver the benefits of the cloud quickly, inexpensively, and without disruption to local systems, Nasuni downloads its Filer, packaged as a virtual machine, onto a host server in the customer’s office. No additional hardware is needed. Setup is fast, and because the Filer resembles a Windows File Server and supports Active Directory, IT Administrators immediately find themselves in a familiar environment.

During installation, Nasuni prompts the customer to select a cloud storage provider or offers a default cloud. Once installation is complete and the technology becomes active, the Filer encrypts files and sends them to the chosen cloud. A copy of the working set is then cached back into the local infrastructure, giving users the fast access they are used to. Deduped snapshots are sent to the cloud, so changes in the working set are safe, protected in the cloud with second copies, along with the rest of the customer’s files.

Core Technology
The Nasuni Filer encompasses our core technology, the Unity File System (UniFS™), along with File Services that allow UniFS™ to function as a virtual NAS device. UniFS™ strengthens security by encrypting both data and metadata with the customer’s keys at the customer’s site, ensuring that others cannot read those files.

High-performance caching algorithms ensure that client files will be present in the cache most of the time, guaranteeing local speeds for all but the least frequently accessed data. If a requested file is not instantiated locally, and has to be pulled back from the cloud, the Unity File System’s chunking and compressi on techniques ensure that it will be retrieved in the fastest way possible, in smaller bits rather than massive blocks of data. Then the file will be re-instantiated in the cache, restoring local speeds.

The cache ends up accelerating the cloud—data is retrieved up to 40 times faster.

Provisioning is automatic: No more adding NAS units or paying for unnecessary space. Instead, UniFS™ ensures that storage expands in tune with each customer’s needs.

Unity File System
The Unity File System consists of four pieces. File Manager handles client read/write requests. Cache Manager runs high-performance algorithms that ensure a high cache hit-rate and performs periodic snapshots. Crypto Layer encrypts files and metadata before forwarding them to the cloud and decrypts data retrieved from the cloud. Finally, Volume Manager interfaces with the cloud providers.

The Unity File System provides the key benefits—including automatic provisioning, snapshots, fast restore, caching, and end-to-end encryption—through these four components.

File Manager
The Unity File System’s first layer, File Manager, receives requests for I/O through CIFS File Services. In the case of a write, File Manager stores the data locally in the cache. With a read, File Manager retrieves the data locally from the cache and sends it back to the client. The performance difference between pulling data out of the cache and doing so from another local disk will be imperceptible to the user. In the event of a cache miss, File Manager defers to Cache Manager.

Cache Manager
Cache Manager relays requests for data that has been evicted from the cache to Volume Manager, then passes that data back to File Manager when it is retrieved from the cloud. Cache Manager also handles one of the core features of Nasuni’s virtual appliance: snapshotting. Periodically, Cache Manager takes a snapshot that essentially forks the file system in an instant. The snapshot is a sub-second operation, so there is no performance hit. Users can continue reading and writing to the cache while Cache Manager works.

Any data that has been saved to the cache but has not yet been copied and pushed to the cloud is considered dirty. Cache Manager is constantly tracking changes to data as they occur and tags dirty data, which includes files created since the last push, or chunks of existing files that were altered in that same interval.

Because Cache Manager is regularly pushing dirty files to the cloud, there is always plenty of clean data that can be evicted if the cache begins filling up. Cache Manager continually monitors how much space it has available on disk. If the cache is getting full, clean data that has already been pushed is deleted. If there is not enough clean data, the system initiates a forced push to the cloud ahead of schedule. Then, some of that newly clean data can be deleted. The end result is that the cache, in effect, never fills up.

Crypto Layer
As large, dirty files move from Cache Manager to Volume Manager, they are segmented into chunks. Each chunk of data is then compressed and encrypted, using OpenPGP with AES-256. Customers have the choice of generating and keeping their own OpenPGP keys, making it impossible for anyone outside of their organization to see their data. Each compressed and encrypted chunk is then forwarded to Volume Manager.

Volume Manager
Volume Manager interfaces with the customer’s chosen cloud provider(s). It pushes chunked and encrypted data to the assigned cloud, then receives and holds the keys required to retrieve that data. Volume Manager takes requests for data from Cache Manager, uses the keys to pull those chunks out of the cloud, and then relays the metadata and files back to Cache Manager.

The metadata is re-instantiated first, so that the file’s critical information appears quickly, and the remains of the file stream back in compressed chunks. These segments are then decrypted and routed through Cache Manager. Because large files flow back in pieces, rather than all at once, the user will begin seeing the file, and be able to work with it, much sooner. This also makes Nasuni’s fast restore possible.

File Services
The Nasuni Filer supports Windows CIFS Shares and Active Directory. As a result, the virtual appliance communicates and integrates with the system like any other NAS device.

Administration Services
This portion controls local NAS administration as well as cloud operations. Nasuni will recommend how much local disk space to assign to the appliance. IT Administrators can create new volumes, manage user shares, monitor system capacity and health, control snapshot frequency, adjust local network bandwidth usage, subscribe to alerts, manage security settings, and run software updates.

The final piece is the Nasuni Connector. Customers do not interact with the Nasuni connector; it is used to perform billing and support functions.