TwinStrata's CloudArray is a brokerage platform between enterprise networks and cloud storage services providers, and we found in testing that it's pretty clever.
CloudArray allows companies to expand their storage resources into the cloud storage provider's assets, subject to the bounds of budget, data rates, and realistic configurations. To operating systems and applications, the CloudArray platform appears as a simple iSCSI connection or CIFS share that's back-ended to the cloud.
CloudArray is simple enough to be installed and used by those with moderate skills. It potentially could be a nightmare for its ability to execute massive rogue data transfers. Fortunately, there are enough checks and balances to prevent hostile data theft. TwinStrata creates a long "paper trail" and secure tracking is done by the CloudArray portal.
CloudArray represents something of a milestone. For more than a decade, there have been connection brokers for OS terminal sessions. Then VMware broke new ground to offer live connection brokerage for virtual machine sessions. What TwinStrata proposes is to serve as a secure connection broker between network devices over iSCSI or CIFS shares that look like one more network hard drive -- of potentially gargantuan size. Our criticisms surround lack of deduplication, and limitations with high-availability/disaster recovery.
We tested TwinStrata with two different cloud storage providers, Amazon's S3 and HP's CloudServices and found that it does the connection brokerage well. It can augment high availability scenarios, but doesn't substitute for a more comprehensive inner network-outer cloud backup and retrieval system. Instead, it extends storage capacity for static, not dynamic data -- files, not necessarily the best for live storage to instances.
The cloud is not your active transparent hard drive with the speed of directly attached SSD -- yet.
How It Works
The TwinStrata platform is an appliance, either a proprietary piece of hardware or a virtual machine equivalent. TwinStrata uses a web interface, and a limited command line vocabulary, along with a configuration (config+keys) that can be saved -- and cache space. The appliance serves as a storage proxy machine between one network and another.
The traffic cop portion of the appliance is a bandwidth scheduler that can be set to lower the speed of network traffic use during peak periods, which is important we found, as CloudArray is both aperiodic and can be really heavy to the point of dominating available bandwidth. CloudArray can be throttled on a seven day, 24-hour basis to prevent its activity from overwhelming other site traffic as it sends data to its cloud destination.
In our tests, we used the virtual machine version of the CloudArray appliance. We configured the VM appliance with a primary and secondary virtual hard drive atop VMware ESXi 5.1, with a 75GB local cache. The cache in turn, goes to the cloud. Specific appliances are available for VMware, XenServer, and Hyper-V; a non-production/sample Windows version was also downloadable.
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