Amazon Glacier vs. On-Premise Tape -

Amazon Glacier vs. On-Premise Tape

Storage requirements for backup and long-term archiving for data protection and disaster recovery are growing at an unmanageable rate. Enterprises of all types need to back up active data regularly to avoid losses, stay compliant, and preserve data integrity. However, legacy data protection approaches such as tape backup are expensive and have become increasingly difficult to manage due to the large number of tapes frequently required for a restore procedure. Plus, new regulatory requirements are putting increasing pressure on existing legacy solutions that were not designed to meet the new realities of today's world.

In addition, enterprises frequently face a challenge getting their backup data offsite on a regular basis. The traditional solution has been to periodically send backup tapes to a records warehouse run by companies, such as Iron Mountain. That creates a lot of work for backup administrators, as they have to create and manage additional jobs to duplicate backup data to tapes for offsite storage, then box up the tapes and deal with the courier. The result is that most companies send tapes offsite only once a week to once a month, which leaves their data highly vulnerable.

AWS Glacier Overview

The latest offering in the Amazon Web Services (AWS) portfolio is a new class or tier of storage service called Glacier, which (as its name implies) has reduced performance and enables support for very large datasets. In other words, Glacier enables very cost-effective support of inactive or seldom-accessed data in exchange for a longer RTO. Specifically, in exchange for an RTO in the order of 3-5 hours, Glacier offers baseline storage costs as low as 1 cent per Gigabyte (GB) or 12 cents per year per GB, in addition to optional fees for access to stored data.

Glacier is designed to help reduce the costs companies typically over-pay for archiving data. It eliminates the requirement that a company must purchase an expensive archiving solution (which does not include the ongoing cost for operational expenses such as power, facilities, staffing, and maintenance). By providing an elastic low-cost storage solution, businesses do not have to guess what their archiving capacity requirements and corresponding costs will be. This eliminates concerns about over-provisioning or under-provisioning these environments while correctly estimating the respective budgets tied to these projects. With Amazon Glacier, you pay only for what you use.

Backup and Archiving ROI Evaluation

This section provides an estimate of the operational cost savings of using Amazon Glacier and traditional on-premise tape backup methods for a typical data backup and archiving scenario. Using such a model, it becomes possible to analyze the ROI of using Glacier as well as tape-based cloud backup and archiving and the possibility of reducing operational costs by investing in a cloud implementation for an actual real world scenario. The model also delineates additional soft benefits that, although difficult to quantify in financial terms, have very real value to a corporation that need to be considered in the cloud backup/archiving deployment model.

Operational Cost Overview: Tape backup systems

A range of enterprises utilize tape for data backup and long-term archiving—and continue to invest in on-premise tape-based backup solutions. With tape-based backup and recovery, IT is responsible for the following tasks:

· Backing up to a tape-based system, then storing the tapes onsite or transporting them to offsite storage. In a remote office, non-technical staff may have to perform this work.

· Recovering data from tapes for restoration to end users or in response to discovery requests.

When preparing the business case showing the ROI for moving to cloud-based backup/archiving, the operational costs of a tape-based backup and recovery system need to be documented.  These cost categories include:

· Labor, whether performed by in-house staff or by contracted services

· Offsite backup tape pickup, storage, and maintenance

The first operational cost category is for labor costs (whether performed by in-house staff or by contracted services) for the range of functions comprising tape-based backup/recovery including:

· Ongoing daily tasks such as running backups, tape management, reviewing logs, and tracking down causes for backup errors.

· Hours spent per month recovering or restoring files for users (both end users and requests for electronic discovery).

· Tasks performed on a periodic basis; for example, performing functional tests to validate that backups run correctly and that data can be restored within an acceptable amount of the time.

The second category of operational costs for tape-based backup and archiving is for offsite backup tape pickup, storage, and maintenance service costs. Such costs are based on the frequency of pickup, storage fees, and charges for maintaining an offsite backup tape collection, including an estimate for the number of times a recovery tape may need to be requested during one year.

Operational Cost Overview: Amazon Glacier for backup/archiving

Glacier-based data backup/recovery and archiving services are uniquely suited to address data protection and long-term preservation and offer the following benefits:

· Backup and archive data moves to an offsite location simplifying data management.

· The cloud option leverages Amazon’s infrastructure and expertise in data durability and availability.

·  Freed from attending to cumbersome, labor-intensive management of tape backup systems, IT personnel can align themselves better with business goals.

Following are the cost efficiencies of a Glacier-based data protection and preservation service:

First, there are no on-going costs for implementing cloud-based data protection and archiving, aside from IT staff’s time spent deciding which types of files to back up, how often to back them up, and how long to retain them. Any costs to manage the life cycle for backup and archive data are borne by Amazon, rather than Glacier customers.

Second, the cloud option does not require any maintenance and media costs for storage infrastructure. Storage fees for backup and archive data (per backup schedule and data retention rules) are included in Glacier monthly fees. Importantly, Glacier passes on its massive economies of scale to customers in the form of very low, competitive rates.

Third, the cloud option allows significant savings for access to backup and archive data. Data on backup tapes is often unrecoverable, and independent studies suggest that a majority of recoveries fail because of errors in the backup process. Unlike the laborious task of tracking errors in tape-based backups for implementing restores, Amazon Glacier provides average annual data durability of 99.999999999% or at an “11 nines” level, so that customers can rest assured that their data will be completely safe while stored within Glacier.

Fourth, with automatic backup and archival to an offsite, highly secure location, there is no additional cost to transport tapes offsite.


For the Glacier option, the operational costs include the costs of storing backup and archival data in Glacier. For the tape backup case, the costs include the costs of tape cartridge hardware, labor costs for managing the tape infrastructure as well as the on-going costs for offsite tape vaulting. The ROI model can be applied to customer scenarios having different base-level assumptions, such as initial source data size, growth data and deduplication ratio, to calculate potential savings that Amazon Glacier may deliver.

Saqib Jang is the founder and principal with Margalla Communications.

Photo courtesy of Shutterstock.

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