Large Active Archives: Data Tape Libraries are Highly Cost-Effective
It is hard to beat the cost per TB of data tape libraries for organizations that have large active archives, whether those organizations are public cloud providers or users with large volumes of data. This is due to the low cost per TB of the cartridges themselves and low system power requirements. It means that tape storage is often an important element, alongside disk and management software, in high capacity active archive systems.
For smaller active archives, cloud object storage offers a level of convenience and cost that makes it attractive. Unlike tape-based storage, a cloud archive can be implemented without need to purchase any additional hardware. It can be up and running very easily and, if there is an adequate Internet connection, it will work well. However, as the amount of archived content goes up, the operating costs of a cloud archive increase almost linearly. Yes, there are discounts for committed cloud capacities, but these are relatively small.
When comparing the cost of tape versus cloud for an active archive, the different purchasing models should be considered in the analysis. A tape-based archive is typically a capital expenditure, whereas cloud is usually an operating expense. After crunching the numbers, the cross-over point where tape and cloud cost about the same is around 100 TB. And for an active archive with one petabyte of stored content, cloud is four or five times higher in cost relative to a tape library solution.
These same economic factors apply to cloud storage providers. Many public cloud providers have introduced object storage with very low-cost archive tiers that take perhaps an hour or more to restore a file. Often these providers use data tape as part of the storage mix. However, many potential users of cloud archive tiers are put off by the very high cost of egress fees, not just for routine restores, but the potentially massive cost if they ever want to move their content to another provider. On-premises tape-based active archives are typically not subject to egress fees and will continue to be attractive to users that have more than 100 TB of content.
But, in the same way that most of life is not black and white, the decision to go with either a tape-based or a cloud-based archive can be much more nuanced. There are hybrid archives that combine the best of both worlds. In the media and advertising industry, large active video archives may take advantage of data tape for storing large high resolution media files but also use cloud storage for collaboration or to take advantage of some of the tools that are available in the cloud. For example, just low resolution proxy files may be stored in the cloud to use AI techniques such as facial recognition and other metadata extraction capabilities that have been developed by the cloud providers. And by using a hybrid storage approach, which stores most content on data tape, costs are kept under control.
Phil Storey, XenData CEO