Amazon Glacier and the Future of Backup and Archiving in the Cloud

Amazon’s AWS group announced a new low-cost cloud-based storage service that offers replicated storage for as low as $0.01 per GB (note: I say as low as because it costs 10% to 20% more in the western United States and outside the United States – but that’s still only 1.1 to 1.2 cents per month per gigabyte.) There are a plethora of other charges as well – for more information see the Amazon Glacier Pricing link.

Here’s what we know about Amazon Glacier so far:

• It’s not tape.
• It’s intended to replace tape.
• Data stored in Glacier takes 3-5 hours to access.
• It is built upon cheap commodity hardware
• It offers replication within a single facility.
• It offers multi-region data replication.
• It supports 256-bit AES encryption.
• It has a claimed 99.999999999% annual data durability guarantee per object.
• AWS import/export is supported for bulk data migration.
• Multi-part uploading is supported.
• AWS will eventually offer an automatic migration system between its S3 storage with lifecycle policies.

Amazon’s AWS S3 pricing is uneffected, so it $0.13/GB to $0.06/GB along with I/O costs (Microsoft’s Azure pricing starts at $0.125.)

So how does this impact backup and archiving? I don’t think that there’s any doubt that this makes public cloud backup a more attractive tertiary destination for backup data. In essence, for small and medium businesses as well as some large enterprises, this makes D2D2C (Disk-to-Disk-to-Cloud) more compelling than D2D2T (Disk-to-Disk-to-Tape.) I can easily see managing your last copy of data within S3 and then using Glacier for all retained data that isn’t on-premise.

At the same time, DRaaS (Disaster Recovery as a Service) is growing in importance – so the management of two-levels of cloud storage will become critical (faster cloud-based spin-up storage versus slower archival storage for system-level data.)

With Glacier costing $10 per terabyte per month ($120 per terabyte per year or $360 for three years), the natural comparison is going to be with LTO-5. A 1.5TB LTO-5 tape can be bought for $50, so that’s about $33/TB, so if you don’t assume reuse, then after 3.3 months, the tape drive will break even in terms of cost. Of course, you have to buy the LTO-5 tape drive, which can put you back $1500 or more – so you’re going to have to store a lot of data in order to get a quick return on investment. Also your operating expenditure is going to dramatically be in favor of cloud-based Glacier.

With that said, I see buyers and customers every day who struggle with 1.5Mbps T1 lines – so in small and medium enterprises I don’t see the bandwidth for cheap storage swap occurring all that quickly.

So what do you think – is Glacier is going to kill tape?