NWA-PCUG Newsletter Article, September 2012
Amazon "Glacier" Offers Ultra Low Cost
Backup Storage

By Ira Wilsker, Radio Show Host,
Columnist, College Professor and deputy sheriff
(click to email author)


Amazon has developed a well earned reputation as a seller of goods. Originally an online book seller, Amazon diversified into consumer and institutional goods, digital books and music, and a variety of other services. Recently, Amazon announced what may be the lowest cost, commercially available "cloud" data storage for long term archival or backup services. Amazon has enormous data capacity, with countless servers and related data storage located in many places around the globe. With the price of data storage plunging precipitously, Amazon has entered the commercial data storage and backup business. As Amazon has had a reputation of supplying goods at highly competitive prices, this new backup service, known as "Glacier" substantially undercuts its competitors in terms of price, with storage being available for as little as a penny per gigabyte per month; at that price a terabyte of storage (1024 gigabytes) would cost only $10.24 per month at the base rate. According to a recent article in "Digital Inspiration", " If your hard drive has 100 GB of data videos, photos, and other important files that you would like to preserve forever, you can transfer all these files to Amazon Glacier and the annual bill would just be a little over $10."

"Glacier" is an appropriate moniker, as this service is intended to be long term "cold storage", rather than storage that is frequently accessed. According to Amazon, there are no up-front costs to set up a storage account and you "Pay only for what you use. There is no minimum fee." While anyone may use Glacier, it is most appropriate for large agencies or businesses, rather than for personal data storage. For those who desire rapid and frequent access to stored data, Amazon offers its "S3" backup and storage service, which is much more expensive. Using the same 100 GB example above, storing that amount of data on S3 would cost about $150 per year, compared to Glacier's $10 per year, but on S3, the data is much more accessible.

Because of its geographic diversity, as Amazon sells its goods and services in many countries, Amazon offers this Glacier storage at five locations, Virginia, Oregon, California, Ireland, and Tokyo. Glacier is designed to be an extremely low cost service that provides secure storage of data for backup and archiving. Glacier is not intended to be used like a hard drive, where data can be quickly accessed and processed, but is instead intended for data that is infrequently accessed, and where immediate access to stored data is not necessary; Amazon says that it may take "several hours" to retrieve data from this system. There is no minimum or maximum amount of storage that must be purchased, and all of the data, regardless of quantity or size, is stored for as little as a penny per gigabyte per month with the user only charged for the space actually used, and an additional fee for data that is accessed or downloaded. There are no advanced or other up-front charges to use Glacier, and the user may freely increase or decrease storage space as needed, again only paying for space that is actually used. There is a very nominal one-time data transfer fee for transferring your files from your personal drive to Glacier, called an "Upload and Retrieval Request" of five cents per 1000 requests, meaning that 10,000 files can be uploaded for a one-time charge of fifty cents. For those who have a large volume of data that needs to be securely stored in Glacier, but who do not have adequate bandwidth or upload speed to efficiently send Glacier massive amounts of data, Amazon offers an alternative to uploading the data via the internet. The user can send Amazon a digital device, such as a hard drive, USB flash drive, or other form of digital media; Amazon will then upload the files directly into its S3 servers, and then return the device to the user. Once on Amazon's S3 servers, the data can be quickly transferred to the more cost efficient (but less accessible) Glacier service, or remain on the more expensive S3 servers. Amazon charges a flat rate of $80 to copy a storage device, plus $2.50 per hour of loading time, so larger capacity devices are more cost efficient for the user. Using the same 100 gb example above, Amazon would charge about $85 (complete) for it to load the 100 gb drive to the server; the $80 device fee, and about 2 hours of load time at $2.50 per hour. there are no limits on how many devices can be sent to Amazon for uploading.

From the user side, Amazon provides the "AWS Management Console" to setup the storage, and upload data. AWS is an acronym for "Amazon Web Services", a web based utility that, " ... provides convenient management of your computer, storage, and other cloud resources." Data is stored in Glacier as "archives" which may contain a single file, or many files, and is uploaded as a single unit or archive. In order to store data in Amazon's Glacier, a vault is created and named. While the volume of data storage is unlimited, the user is limited to creating a maximum of 1000 vaults in each of Amazon Glacier's five regions (Virginia, Oregon, California, Ireland, Tokyo). Into each vault the user can upload countless archives, with the 40TB limit per archive. The archive packages are securely stored and organized in virtual "vaults". These vaults are created by the user using the AMS Management Console. Each archive is limited to 40 terabytes, and there is no limit to the number of archives that can be stored on Glacier. The vaults are heavily encrypted (AES-256), and accessible by using Amazon's "IAM" Identity and Access Management service.

According to a blog posting by Werner Vogels, Amazon's chief technology officer, "The service redundantly stores data in multiple facilities and on multiple devices within each facility." Amazon claims that with the redundant storage in the cloud, files will have an " ... average annual durability of 99.999999999%", meaning that if 100 billion files or other objects are stored in Glacier, only one will be lost in any year.

Since Glacier is intended as stable, long term cold storage, retrieving files and data from Glacier is slower, and entails some cost. To retrieve an archive from Glacier requires that a job is initiated, which may take three to five hours to complete. There may be a fee for retrieving data in excess of 5% of the amount of data stored; up to 5% of stored files may be retrieved each month for free. Past that 5% free data retrieval cap, Amazon charges 12 cents per gigabyte downloaded, for the first 10 terabytes, with a descending rate for downloads greater than that. There is also a three cents per gigabyte fee for deleting newly uploaded files within 90 days.

Amazon offers a variety of other data storage and retrieval services, one of the most popular being its Simple Storage Service, known as S3. As stated previously, the data stored on the S3 servers are more accessible than they are on Glacier, but at a price. S3 offers a Free Usage Tier, where new Amazon Web Services (AWS) customers receive 5 GB of Amazon S3 storage, 20,000 Get Requests, 2,000 Put Requests, and 15GB of data transfer out each month for one year. Beyond the Free Usage Tier, up to a terabyte of storage is available for 12.5 cents per gigabyte per month for redundant storage, and 9.3 cents per gigabyte per month for a reduced redundancy storage system; the rate decreases significantly with larger volumes of storage. There are no inbound fees for uploading data to S3, but there are fees for downloading data, starting at 12 cents per gigabyte, again decreasing with volume.

There are some free alternatives available for remote backup and storage; Microsoft offers its free SkyDrive service (skydrive.live.com), with a 7 GB limit on free storage (users who signed up earlier this year had a 25 GB limit), and Google offers its Google Drive (drive.google.com), free for the first 5 GB of storage. Several other online services also offer free online backups with various limits on the amount of free storage. There are many other sellers of commercial backup services, with varying prices and services.

With the three most important words in computing being, "Backup !, Backup !, Backup !", Amazon, Google, Microsoft, and other providers of backup services provide a cost effective and secure alternative to the more traditional on-site backup methods. These cloud based backup services are very worthy of consideration.

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