Comparing Cloud Storage and LTO for Creative Video

We launched our Cloud File Gateway at NAB in Las Vegas last week and discussed its place in the storage hierarchy with many of the visitors to our booth. We focused on the merits of cloud storage versus a more conventional local LTO library for archived video content.

From my NAB discussions, it was clear that there is often a misunderstanding about the positioning of cloud storage. It is typically thought of as being a low cost, low performance alternative. This perception is likely due to the free entry-level offerings such as OneDrive from Microsoft and iCloud from Apple. In reality, enterprise class cloud storage is neither lower cost nor lower performance when compared with LTO.

The XenData Cloud File Gateway writes to and restores from Microsoft’s Azure blob storage which is highly scalable in both capacity and transfer rates. If your Internet bandwidth is high enough, the performance is amazing with instant access to your content and fast transfer rates. Of course, Internet bandwidth is usually not cheap.

Using Azure blob storage as an example, the monthly cost depends on a number of factors:

  • Capacity – the volume of data held in the cloud
  • Data Retrieval and Download Bandwidth – the volume of data restored from the cloud
  • Data Write – the volume of data written to the cloud
  • Operations – transactions such as delete, index operations, etc.

Feedback from NAB discussions told me that there is need for a clear description of Azure pricing and this will be the topic for another blog posting. The cost for capacity is easy to understand and estimate. Data writes and operations are typically relatively inexpensive but if you download a lot of content, data retrieval costs can skyrocket.

As an example, the Azure monthly cost for 50 TB held in the cool tier of Azure blob storage can be as low as $512 per month without uploading or downloading any data. Each TB uploaded will add less than $2 to the bill. However, restoring 1TB incurs an additional cost of almost $100. With a good Internet connection, the restore performance is excellent but the restores are pricey!

The XenData Gateway functionality is aimed at getting the most from cloud storage at the lowest cost. It will manage up to 256 TB of RAID held on-premises which minimizes the need to restore from the cloud. Furthermore it supports partial file restore (PFR) which means that just a portion of a large file can be downloaded to create a video clip, saving on download cost.

In summary, the common perception that cloud storage is the lowest cost and lowest performance tier of storage is incorrect. Think of cloud as a higher performance and higher cost alternative to a local LTO library.