Review: Cloud storage

Nasuni raises the bar for hybrid cloud storage

hybrid cloud

As growth in cloud-based storage products continues to accelerate, enterprise vendors have taken cloud storage to the next level. The hybrid model, which utilizes both local and offsite storage, offers organizations a way to more seamlessly scale up and manage large amounts of data with a single-vendor service.

We tested Version 6 of Nasuni’s hybrid solution, which it calls Enterprise Storage as a Service. The components of Nasuni’s subscription-based service include a local storage appliance (Nasuni Filer), management tools, built-in antivirus, cloud gateway/cloud broker and cloud storage, currently offered on either the Microsoft Azure or Amazon EC2 cloud platforms.

The Nasuni Filer is available as a hardware appliance or virtual machine. We tested the Nasuni Filer appliance NF-440 model 2U unit with 20+ 600 GB drives, which is similar to the standard subscription of 12TB. We also tested the Filer configured as a virtual appliance on a server running Windows Server 2008 R2 hypervisor, and the Nasuni Management Console (NMC), also configured as a VM.

The basic startup and configuration of the Nasuni Filer was quick and uncomplicated. Using DHCP we were able to access the Filer’s Web GUI over SSL in less than 10 minutes from power up. There are only a couple of steps involved in getting the Filer ready for first use, such as configuring the network, providing a user name and password and assigning a serial number, which starts the process of registering the Filer on the Nasuni network.

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Once the home page appears you have the option of uploading your own encryption keys, integrating with Active Directory security and performing other basic setup tasks such as setting date/time and adding an email for notification purposes.

The Filer comes with a default volume named ‘files’ already created, which the user can rename or create additional new volumes. With no data yet stored in the cloud, the Filer starts out as essentially a file server or attached storage on the local network. Volumes are mapped just like a regular file server or other storage device. However with over 13TB (22 x 600 GB drives), the local storage capacity of the Nasuni Filer we tested was truly impressive, worth all 80+ pounds. But of course local storage is only part of the story.

Once data is copied to a volume, the Filer goes to work uploading snapshots to the cloud. The initial snapshot copies all data currently on the Filer to the cloud and subsequent snapshots only synchronize changes made since the initial snapshot. Data that has been moved to the cloud is saved back to the local cache when requested as opposed to being accessed directly from the cloud. The default interval for snapshots is once per hour, but this can be modified to as frequent as every minute. Our initial batch of data, which was about 3GB, including several files in the hundreds of megabytes, initially took over 12 hours to be copied to the cloud. At first we were concerned about the seemingly sluggish transfer, but a deeper dive showed that we needed to tweak a few settings to boost performance.

pros cons for cloud storage Nasuni

Settings can be applied by volume or by Filer. As data is stored to the Filer it is in what Nasuni calls the cache, stored locally. The percentage reserved for new incoming data can be set from 5% to 90%; a larger number means less data is stored locally and more data is moved to the cloud. The default setting is ‘automatic’, meaning the Filer manages the best use of the cache. In order to keep the local cache from filling up, data is ‘evicted’ to the cloud as needed. In order to keep certain data always available in the local cache, you can "pin" folders, and if "pinned" data is taking up too much storage, an alert is issued.

The system is designed to ensure that frequently used data is stored on a local Filer for rapid retrieval, using what Nasuni refers to as a Least Recently Used (LRU) algorithm. Some of the settings depend on the intended usage of the Filer; one organization may only want to use the Filer for backup purposes whereas another may use it as their primary file storage or for high performance shared applications. It is also possible to set up different volumes for different purposes, customized for each task.

After specifying a more frequent snapshot interval on our Filer, and using QoS settings to allocate more bandwidth for the cloud transfer, performance on our test Filer increased dramatically. With a shorter snapshot duration, smaller files were sent to the cloud almost immediately, making the Filer seem almost like local storage. However unlike local storage, the Nasuni Filer only sends snapshots to the cloud one volume at a time.

Each Nasuni Filer can be managed individually using a built-in Web interface. Multiple Filers can be centrally managed using the Nasuni Management Console (NMC). We set up the NMC as a virtual machine under Windows Server 2008 Hyper-V. After setting the Filer to be centrally managed by the NMC, we noticed that some of the previously-available configuration options in the local management interface had been disabled. This is by design, as the NMC at that point has taken over the bulk of management tasks.

Initially, the NMC displays an overview of the storage environment; e.g. how many Filers and volumes are under management, how much storage is used and how much is available. It also displays graphs showing live network traffic, file types and the health status of each managed Filer. A notification system displays system alerts.

Ours kept reminding us that one of our virtual machines was low on memory until we allocated more. On the hardware Filer, we forgot to plug in one of the power supplies and the Filer kept notifying us of this condition until we corrected it. Notifications can be sorted by various parameters, such as severity and date, and each notification must be acknowledged in order to drop off the list.

Overall, we found the web-based NMC and Nasuni support to be among the best we’ve ever tested. We called customer support on a Sunday evening to resolve an issue with the VM used for the management console. We were pleasantly surprised to get a call back in less than 10 minutes and several pointers to get the issue resolved. However it was later explained to us that late night phone support is usually reserved for more critical issues like unresponsive systems and situations more serious than ours. Throughout the test experience we found the Nasuni support teams to be knowledgeable and responsive to the few issues we encountered.

Depending on subscription levels, Nasuni cloud storage can be virtually limitless, provided you don’t exceed the subscription capacity at any given time. With north of 12TB of available cache space on our Filer we did not run into a problem with this. Snapshots settings offer granularity that will fit most common storage scenarios.

For instance, you can customize the ‘Quality of Service’ setting, which is essentially the bandwidth made available for uploads/downloads, depending on the time of day. With QoOS settings, snapshots taken during business hours could be limited to give precedence to user traffic, and re-prioritized during non-peak hours to allow snapshots to be performed at a faster pace.

In addition to accessing Nasuni-managed data as a shared volume, it can also be accessed via FTP, Web browser and mobile devices. Mobile access is available for Android and iOS devices through respective Nasuni apps available for both platforms. Currently only CIFS-enabled volumes are accessible from mobile devices. Most file operations can be performed by mobile users, such as viewing, deleting, uploading and downloading. There is also a Nasuni desktop client that provides portal access to a Nasuni Filer. It is available for Linux, Windows and OS X. The only downside is that the desktop version only allows access to one Filer at a time.

On the security front, Nasuni-managed data is encrypted over SSL both locally and in the cloud. Encryption keys are generated and kept by the user, rendering the data useless and unreadable without the proper key. User access can be defined on a more granular level by assigning roles and read/write permissions to volumes on the Filer. The Filer also has built-in antivirus protection that, if enabled, scans each new or modified file saved to the Filer. For external monitoring, the Filer supports SNMP access.

New features in Nasuni 6.0 include global locking, file virtualization and desktop file synchronization. Global locking takes traditional locking typically used with a local file server and extends it across multiple geographic locations. Global locking can be configured on the folder level allowing for granular control where it is needed. When a file lock is requested, it is submitted to the Nasuni Global Locking Service. If no lock is already present, a lock is issued. The local cache is then checked to make sure the latest version of the file is available and updates from the cloud are merged if necessary before the file is opened.

Data virtualization uses Nasuni’s patented UniFS Global File System to make the same data globally available to all users by storing only one master source of the data. This is accomplished without physically replicating the data, thus reducing the need to locally manage end-user file data. In combination with caching on local filers, data virtualization provides "global" access essentially the same as if the data was accessed from a local file server.

Desktop File Synchronization gives users the ability to create a local folder that is synchronized to the Nasuni cloud. This synchronized folder provides global access to user files from multiple devices such as tablets, smartphones and computers.

Strategically, Nasuni views its solution as a best fit for organizations currently using NAS storage that have 5TB or more of data to manage across multiple locations. A starter bundle of 5TB of licensed storage, five virtual filers and a mid-range physical filer, start-up services, and ongoing maintenance, support and upgrades is $25,000.

Aimed at smaller businesses with less data to manage, Nasuni is introducing a lower-cost Filer, the NF-100, with exact specs and pricing to be announced. There is also a new desktop Filer in the works, slated for release in the fourth quarter of 2014.

Perschke is the CEO of Arc Seven Technology, a niche provider of managed web hosting and data-driven cloud apps. When not chained to a desk, Susan is out camping with a high-level corporate exec (OK, he’s her husband) and snapping nature shots with her Nikon D3100. She can be reached at

Copyright © 2014 IDG Communications, Inc.

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