Amazon Glacier FAQs

Q: What is Amazon Glacier?

Amazon Glacier is an extremely low-cost storage service that provides secure, durable, and flexible storage for data backup and archival. With Amazon Glacier, customers can reliably store their data for as little as $0.01 per gigabyte per month. Amazon Glacier enables customers to offload the administrative burdens of operating and scaling storage to AWS, so that they don’t have to worry about capacity planning, hardware provisioning, data replication, hardware failure detection and repair, or time-consuming hardware migrations.

Q: How can businesses, government and other organizations benefit from Amazon Glacier?

Amazon Glacier enables any business or organization to easily and cost effectively retain data for months, years, or decades. With Amazon Glacier, customers can now cost effectively retain more of their data for future analysis or reference, and they can focus on their business rather than operating and maintaining their storage infrastructure.

Q: How should I choose between Amazon Glacier and Amazon Simple Storage Service (Amazon S3)?

Amazon S3 is a durable, secure, simple, and fast storage service designed to make web-scale computing easier for developers. Use Amazon S3 if you need low latency or frequent access to your data. Use Amazon Glacier if low storage cost is paramount, your data is rarely retrieved, and data retrieval times of several hours are acceptable.

Amazon S3 now provides a new storage option that enables you to utilize Amazon Glacier’s extremely low-cost storage service for data archiving. You can define S3 lifeycycle rules to automatically archive sets of Amazon S3 objects to Amazon Glacier to reduce your storage costs. You can learn more by visiting the Object Lifecycle Management topic in the Amazon S3 Developer Guide.

Q: What kind of data can I store?

You can store virtually any kind of data in any format. Please refer to the Amazon Web Services Licensing Agreement for details.

Q: What does Amazon do with my data in Amazon Glacier?

Amazon will store your data and track its associated usage for billing purposes. Amazon will not otherwise access your data for any purpose outside of the Amazon Glacier offering, except if required to do so by law. Please refer to the Amazon Web Services Licensing Agreement for details.

Q: How do I use Amazon Glacier?

Amazon Glacier provides a simple, standards-based REST web services interface as well as Java and .NET SDKs. The AWS Management console can be used to quickly set up Amazon Glacier. Data can then be uploaded and retrieved programmatically. View our documentation for more information on the Glacier APIs and SDKs.

Q: How durable is Amazon Glacier?

Amazon Glacier is designed to provide average annual durability of 99.999999999% for an archive. The service redundantly stores data in multiple facilities and on multiple devices within each facility. To increase durability, Amazon Glacier synchronously stores your data across multiple facilities before returning SUCCESS on uploading archives. Glacier performs regular, systematic data integrity checks and is built to be automatically self-healing.

Q: How is data within Amazon Glacier organized?

You store data in Amazon Glacier as an archive. Each archive is assigned a unique archive ID that can later be used to retrieve the data. An archive can represent a single file or you may choose to combine several files to be uploaded as a single archive. You upload archives into vaults. Vaults are collections of archives that you use to organize your data.

Q: How much data can I store?

There is no maximum limit to the total amount of data that can be stored in Amazon Glacier. Individual archives are limited to a maximum size of 40 terabytes.

Q: What is the minimum amount of data that I can store using Amazon Glacier?

There is no minimum limit to the amount of data that can be stored in Amazon Glacier and individual archives can be from 1 byte to 40 terabytes.

Q: Does the AWS Management Console support Amazon Glacier?

Yes. The AWS Management Console allows you to create and configure vaults, allowing you to easily and quickly setup Glacier. Click here to go the AWS Management Console.

Q: How do vaults work?

You use vaults to organize the data you store in Amazon Glacier. Each archive is stored in a vault of your choice. You may control access to your data by setting vault-level access policies using the AWS Identity and Access Management (IAM) service. You can also attach notification policies to your vaults. These enable you or your application to be notified when data that you have requested for retrieval is ready for download. Click here to learn more about setting up notifications using the Amazon Simple Notification Service (Amazon SNS).

Q: How many vaults can I create?

You can create up to 1,000 vaults per account per region.

Q: How do I delete a vault?

You may delete any Glacier vault that does not contain any archives using the AWS Management Console, the Amazon Glacier APIs or the SDKs. Once a vault has been deleted, you can then re-create a vault with the same name. If your vault contains archives, you must delete all the archives before deleting the vault.

Q: What is an archive?

An archive is a durably stored block of information. You store your data in Amazon Glacier as archives. You may upload a single file as an archive, but your costs will be lower if you aggregate your data. TAR and ZIP are common formats that customers use to aggregate multiple files into a single file before uploading to Amazon Glacier. The total volume of data and number of archives you can store are unlimited. Individual Amazon Glacier archives can range in size from 1 byte to 40 terabytes. The largest archive that can be uploaded in a single Upload request is 4 gigabytes. For items larger than 100 megabytes, customers should consider using the Multipart upload capability. Archives stored in Amazon Glacier are immutable, i.e. archives can be uploaded and deleted but cannot be edited or overwritten.

Q: How do I delete archives?

You can delete an archive at any time. You will stop being billed for your archive when your delete request succeeds at which point the archive itself will be inaccessible. Archives that are deleted within 3 months of being uploaded will be charged a deletion fee (see billing section for more details).

Q: How do I upload large archives?

When uploading large archives (100MB or larger), you can use multi-part upload to achieve higher throughput and reliability. Multi-part uploads allow you to break your large archive into smaller chunks that are uploaded individually. Once all the constituent parts are successfully uploaded, they are combined into a single archive.

Q: How can I retrieve data from the service?

You can download data directly from the service using the service’s REST API. When you make a request to retrieve data from Glacier, you initiate a retrieval job. Once the retrieval job completes, your data will be available to download for 24 hours. Retrieval jobs typically complete within 3-5 hours.

Q: What operations initiate jobs and why?

To retrieve an archive or a vault inventory, you first initiate a job (Click here for more information about vault inventories). Once you initiate a job, you can call the DescribeJob API to monitor its progress. You can also have notifications automatically sent to you once a job completes. Jobs will typically complete in 3-5 hours. Once a job completes successfully, you can download the data requested or access it using Amazon Elastic Compute Cloud (Amazon EC2).

Q: How long does it take for jobs to complete?

Most jobs will take between 3 to 5 hours to complete.

Q: Can I retrieve part of an archive?

Yes, range retrievals enable you to retrieve a specific range of an archive. Range retrievals are similar to regular retrievals in Amazon Glacier. Both require the initiation of a retrieval job that typically completes within 3-5 hours (See How can I retrieve data? for more information). You can use range retrievals to reduce or eliminate your retrieval fees (See How much data can I retrieve for free?)

When initiating a retrieval job using range retrievals, you provide a byte range that can start at zero (which would be the beginning of your archive), or at any 1MB interval thereafter (e.g. 1MB, 2MB, 3MB, etc). The end of the range can either be the end of your archive or any 1MB interval greater than the beginning of your range.

Q: Why would I retrieve only a range of an archive?

There are several reasons why you might choose to perform a range retrieval. For example, you may have aggregated several files and uploaded them as a single archive. You may then need to retrieve a small selection of those files, in which case you could retrieve only the ranges of the archive that contained the required files. Another reason you could choose to perform a range retrieval is to manage how much data you download from Amazon Glacier in a given period. When data is retrieved from Amazon Glacier, a retrieval job is first initiated, which will typically complete in 3-5 hours. The data retrieved is then available for download for 24 hours. You could therefore retrieve an archive in parts in order to manage the schedule of your downloads. You may also choose to perform range retrievals in order to reduce or eliminate your retrieval fees. If you exceed your free retrieval allowance, you pay a retrieval fee that is based on your peak retrieval rate. Spreading out a retrieval of an archive in smaller parts could therefore allow you reduce your retrieval fees, by reducing your peak retrieval rate. (Click here to learn more about what it costs to retrieve data from Amazon Glacier).

Q: How do I view my jobs?

You can list your ongoing jobs for any of your vaults by calling the ListJobs API. The list of jobs provides information including the job’s creation time and date and the job’s status (e.g. in-progress, completed successfully, or not in which case reasons for the job not succeeding are provided). The progress of a single job can be tracked by calling the DescribeJob API and providing the corresponding job ID. The status of the job will be returned immediately.

Q: Can I be notified when a job is completed?

Yes. You can optionally configure vaults to send notifications to you or your application when jobs complete. Notifications will be delivered via the Amazon Simple Notification Service (Click here to learn more about Amazon SNS).

Q: Can I see what archives I have stored in Amazon Glacier?

Yes. Although you will need to maintain your own index of data you upload to Amazon Glacier, an inventory of all archives in each of your vaults is maintained for disaster recovery or occasional reconciliation purposes. The vault inventory is updated approximately once a day. You can request a vault inventory as either a JSON or CSV file and will contain details about the archives within your vault including the size, creation date and the archive description (if you provided one during upload). The inventory will represent the state of the vault at the time of the most recent inventory update.

Q: Can I obtain a real time list of my vaults?

Yes, you can list your vaults stored in Amazon Glacier using either the AWS Management Console or by calling the ListVaults API. As well as a list of vault names, you will also be able to see when the vault’s inventory was last updated and a summary of the vault’s contents at that time, as well as the vault’s creation date and creator.

Q: How do I control access to my data?

By default, only you can access your data. In addition, you can control access to your data in Amazon Glacier by using the AWS Identity and Access Management (AWS IAM) service. You simply set up an AWS IAM policy that specifies which users within an account have rights to operations on a given vault.

Q: Is my data encrypted?

Yes, all data in the service will be encrypted on the server side. Amazon Glacier handles key management and key protection for you. Amazon Glacier uses one of the strongest block ciphers available, 256-bit Advanced Encryption Standard (AES-256). 256-bit is the largest key size defined for AES. Customers wishing to manage their own keys can encrypt data prior to uploading it.

Q: Does Amazon Glacier support IAM permissions?

Yes, Glacier will support API-level permissions through AWS Identity and Access Management (IAM) service integration

For more information about IAM, go to:

• AWS Identity and Access Management
• AWS Identity and Access Management Getting Started Guide
• Using AWS Identity and Access Management

Q: How much does Amazon Glacier cost?

With Amazon Glacier, storage is priced from $0.01 per gigabyte per month, and you pay for what you use. There are no setup fees, and for most archive use cases your total costs will primarily be made up of your storage cost.

Upload and Retrieve requests are priced from $0.05 per 1,000 requests. For large retrievals, there is also retrieval fee starting at $0.01 per gigabyte. In addition, there is a pro-rated charge of $0.03 per gigabyte for items that are deleted prior to 90 days. As Amazon Glacier is designed to store data that is infrequently accessed and long lived, these charges will likely not apply to most of you.

We charge less where our costs are less. Some prices vary across Amazon Glacier Regions and are based on the location of your vault. There is no Data Transfer charge for data transferred between Amazon EC2 and Amazon Glacier within the same Region. Data transferred between Amazon EC2 and Amazon Glacier across all other Regions (e.g. between the Amazon EC2 Northern California and Amazon Glacier US East North Virginia Regions) will be charged at Internet Data Transfer rates on both sides of the transfer.

To learn more about Glacier pricing, please visit the Glacier pricing page.

Q: How is my storage charge calculated?

The volume of storage billed in a month is based on the average storage used throughout the month, measured in gigabyte-months (GB-Months). The size of each of your archives is calculated as the amount of data you upload plus an additional 32 kilobytes of data for indexing and metadata (e.g. your archive description). This extra data is necessary to identify and retrieve your archive. Here is an example of how to calculate your storage costs using US East (Northern Virginia) Region pricing:

If you upload 100,000 archives that are 1 gigabyte each, your total storage would be:

1.000032 gigabytes for each archive x 100,000 archives = 100,003.20 gigabytes

If you stored the archives for 1 month, you would be charged:

100,003.20 GB-Months x $0.01 = $1,000.03

If you upload 200,000 archives that are 0.5 gigabytes each, your total storage would be:

0.500032 gigabytes for each archive x 200,000 archives = 100,006.40 gigabytes

If you stored the archives for 1 month, you would be charged:

100,006.40 GB-Months x $0.01 = $1,000.06

Your storage is measured in “TimedStorage-ByteHrs,” which are added up at the end of the month to generate your monthly charges. For example, if you store an archive that is 1 gigabyte (inclusive of the 32 kilobyte overhead) for one day in the US East (Northern Virginia) Region, your storage usage would be:

1,073,741,824 bytes x 1 day x 24 hours = 25,769,803,776 Byte-Hours

Converting this to GB-Months (assuming a 30 day month) gives:

25,769,803,776 Byte-Hours x (1 GB / 1,073,741,824 bytes) x (1 month / 720 hours) = 0.03 GB-Months

So your storage charge for that day would be:

0.03 GB-Months x $0.01 = $0.0003

To learn more about Glacier pricing and view prices for other regions, please visit the Glacier pricing page.

Q: Why do prices vary depending on which Amazon Glacier Region I choose?

We charge less where our costs are less. For example, our costs are lower in the US East (North Virginia) Region than in the US West (Northern California) Region.

Q: How will I be charged and billed for my use of Amazon Glacier?

There are no setup fees to begin using the service. At the end of the month, your credit card will automatically be charged for that month’s usage. You can view your charges for the current billing period at any time on the Amazon Web Services web site, by logging into your Amazon Web Services account, and clicking “Account Activity” under “Your Web Services Account”.

Q: How much data can I retrieve for free?

You can retrieve up to 5% of your data stored in Glacier for free each month. Typically this will be sufficient for backup and archival needs. Your 5% monthly free retrieval allowance is calculated and metered on a daily prorated basis. For example, if on a given day you have 12 terabytes of data stored in Glacier, you can retrieve up to 20.5 gigabytes of data for free that day (12 terabytes x 5% / 30 days = 20.5 gigabytes, assuming it is a 30 day month).

Your daily allowance is calculated based on the amount of data you have stored in Glacier, as per your vault inventories. See the Glacier developer guide for more details about vault inventories

Q: How will I be charged when retrieving large amounts of data from Amazon Glacier?

You can retrieve up to 5% of your average monthly storage, pro-rated daily, for free each month. For example, if on a given day you have 75 TB of data stored in Amazon Glacier, you can retrieve up to 128 GB of data for free that day (75 terabytes x 5% / 30 days = 128 GB, assuming it is a 30 day month). In this example, 128 GB is your daily free retrieval allowance. Each month, you are only charged a Retrieval Fee if you exceed your daily retrieval allowance. Let's now look at how this Retrieval Fee - which is based on your monthly peak billable retrieval rate - is calculated.

Let’s assume you are storing 75 TB of data and you would like to retrieve 140 GB. The amount you pay is determined by how fast you retrieve the data. For example, you can request all the data at once and pay $21.60, or retrieve it evenly over eight hours, and pay $10.80. If you further spread your retrievals evenly over 28 hours, your retrievals would be free because you would be retrieving less than 128 GB per day. You can lower your billable retrieval rate and therefore reduce or eliminate your retrieval fees by spreading out your retrievals over longer periods of time.

Below we review how to calculate Retrieval Fees if you stored 75 TB and retrieved 140 GB in 4 hours, 8 hours, and 28 hours respectively.

First we calculate your peak retrieval rate. Your peak hourly retrieval rate each month is equal to the greatest amount of data you retrieve in any hour over the course of the month. If you initiate several retrieval jobs in the same hour, these are added together to determine your hourly retrieval rate. We always assume that a retrieval job completes in 4 hours for the purpose of calculating your peak retrieval rate. In this case your peak rate is 140 GB/4 hours, which equals 35 GB per hour.

Then we calculate your peak billable retrieval rate by subtracting the amount of data you get for free from your peak rate. To calculate your free data we look at your daily allowance and divide it by the number of hours in the day that you retrieved data. So in this case your free data is 128 GB /4 hours or 32 GB free per hour. This makes your billable retrieval rate 35 GB/hour – 32 GB per hour which equals 3 GB per hour.

To calculate how much you pay for the month we multiply your peak billable retrieval rate (3 GB per hour) by the retrieval fee ($0.01/GB) by the number of hours in a month (720). So in this instance you pay 3 GB/Hour * $0.01 * 720 hours, which equals $21.60 to retrieve 140 GB in 3-5 hours.

First we calculate your peak retrieval rate. Again, for the purpose of calculating your retrieval fee, we always assume retrievals complete in 4 hours. If you request 70GB of data at a time with an interval of at least 4 hours, your peak retrieval rate would then be 70GB / 4 hours = 17.50 GB per hour. (This assumes that your retrievals start and end in the same day).

Then we calculate your peak billable retrieval rate by subtracting the amount of data you get for free from your peak rate. To calculate your free data we look at your daily allowance and divide it by the number of hours in the day that you retrieved data. So in this case your free data is 128 GB /8 hours or 16 GB free per hour. This makes your billable retrieval rate 17.5 GB/hour – 16 GB per hour which equals 1.5 GB/hour. To calculate how much you pay for the month we multiply your peak hourly billable retrieval rate (1.5 GB/hour) by the retrieval fee ($0.01/GB) by the number of hours in a month (720). So in this instance you pay 1.5 GB/hour x $0.01 x 720 hours, which equals $10.80 to retrieve 40 GB.

If you spread your retrievals over 28 hours, you would no longer exceed your daily free retrieval allowance and would therefore not be charged a Retrieval Fee.

As you can see, you are able to significantly reduce, or eliminate, your retrieval fees when longer retrieval periods are suitable, as is often the case for archived data.

To learn more about Glacier pricing, please visit the Glacier pricing page.

Q: How will I be charged when retrieving only a range of an archive?

Range retrievals are priced in precisely the same way as regular retrievals from Amazon Glacier. The amount of data that you specify in your range retrieval requests are summed in order to determine whether your retrievals fall within your daily free retrieval tier. (See How much data can I retrieve for free to learn more). Range retrievals make it even easier for you to retrieve data without paying any retrieval fees. In the event that you do exceed your daily free retrieval tier, it is the range that you request that will determine your retrieval rate. (See How will I be charged when retrieving large amounts of data from Amazon Glacier? to learn more).

Q: How will I be charged for deleting data that is less than 3 months old?

Amazon Glacier is designed for use cases where data is retained for months, years, or decades. Deleting data from Amazon Glacier is free if the archive being deleted has been stored for three months or longer. If an archive is deleted within three months of being uploaded, you will be charged an early deletion fee. In the US East (Northern Virginia) Region, you would be charged a prorated early deletion fee of $0.03 per gigabyte deleted within three months. So if you deleted 1 gigabyte of data 1 month after uploading it, you would be charged a $0.02 early deletion fee. If, instead you deleted 1 gigabyte after 2 months, you would be charged a $0.01 early deletion fee.

To view prices for other regions, visit the Glacier pricing page.

Q: What can I expect the total cost of ownership (TCO) to be?

In a typical archive use case, data is retained for many years with the data often going months without being accessed. When data is retrieved, it is often a small subset of the total data stored. For example, let’s assume you upload 1 petabyte of data to Glacier, and each archive is 10 megabytes. If you retain your data for three years, and retrieve up to 10TB a month, retrieving less than your free allowance each day (i.e. less than 3.3 terabytes a day), your monthly TCO over the 3 year period would be $ $10,689 or ~$0.01 per gigabyte per month.

To learn more about Glacier pricing, please visit the Glacier pricing page.

Q: Do your prices include taxes?

Except as otherwise noted, our prices are exclusive of applicable taxes and duties, including VAT and applicable sales tax. For customers with a Japanese billing address, use of the Asia Pacific (Tokyo) Region is subject to Japanese Consumption Tax. Learn more.

Q: What are data retrieval policies?

Amazon Glacier data retrieval policies let you define your own data retrieval limits with a few clicks in the AWS console. You can limit retrievals to “Free Tier Only”, or if you wish to retrieve more than the free tier, you can specify a “Max Retrieval Rate” to limit your retrieval speed and establish a retrieval cost ceiling. In both cases, Amazon Glacier will not accept retrieval requests that would exceed the retrieval limits you defined. To learn more please read Configuring Data Retrieval Policies in the Amazon Glacier developer’s guide.

Q: How do I set up data retrieval policies?

You can set up data retrieval policies in the Amazon Glacier console or via the Amazon Glacier APIs. To learn more please read Configuring Data Retrieval Policies in the Amazon Glacier developer’s guide.

Q: Are data retrieval policies specific to each AWS region?

Yes. You can set one data retrieval policy for each AWS region which will govern all data retrieval activities in the region under your account. Data retrieval policies are region-specific because data retrieval costs vary across AWS regions and the 5% free retrieval tier is also computed based on your storage within the region. Please visit Amazon Glacier Pricing for more information.

Q: Can I use data retrieval policies to “slow down” my retrievals or spread them out?

No, data retrieval policies such as “Free Tier Only” and “Max Retrieval Rate” will not accept a data retrieval request which would exceed your predefined data retrieval limit to help you manage data retrieval cost. Data retrieval policies will not change the 3 to 5 hour data retrieval latency or spread out your retrievals. You can leverage Amazon Glacier’s range retrieval feature to spread out retrievals and lower the peak retrieval speed. Learn more.

Q: How is my storage charge calculated if I set a “Max Retrieval Rate” and my retrievals exceed the free tier?

Let’s suppose you have 10 GB of free retrieval allowance per day and you set a “Max Retrieval Rate” of 20 GB/hr which shows a data retrieval cost estimate of “$144.00/month or less” in the AWS console (assuming US East region and a 30 day month).

Now let’s walk through a few scenarios, assuming this is a new month.

On day 1, you issued a retrieval request for an 8 GB archive. Since 8 GB was less than the free retrieval allowance for the day, your retrieval request was accepted and the data retrieval was free.

On day 2, your coworker accidentally issued a retrieval request for a 100 GB archive by mistake. Because the retrieval rate (based on 4 hour completion) would be 100 GB/4 hours = 25 GB/hr, exceeded the 20 GB/hr “Max Retrieval Rate”, the request was rejected and there was no data retrieval charges incurred.

On day 3, you issued a retrieval request for a single 40 GB archive. Since all data retrieval billing assumes the retrievals complete in 4 hours, 40 GB/ 4 hours yielded a retrieval rate of 10 GB/hr which was below the 20 GB/hr “Max Retrieval Rate” you set, so your retrieval request was accepted. Your peak billable retrieval rate for the day was (40 GB – 10 GB free tier) divided by 4 hours which yielded 7.5 GB/hr. Your estimated data retrieval bill at this point would be 7.5 GB/hr * $0.01 per GB* 720 hours per month = $54 for the month and was below the data retrieval cost estimate of $144.00/month shown in the console.

On day 4, you issued a retrieval request for a 40 GB archive immediately followed by another request for a 44 GB archive. The request for the 40 GB archive was accepted because the retrieval rate (based on 4 hour completion) was 40 GB/4 hours = 10 GB/hr, which was less than the 20 GB/hr “Max Retrieval Rate”. The second request to retrieve a 44 GB archive however, was rejected because while the request alone only yielded 44 GB/4 hours = 11 GB/hr of retrieval rate, the first retrieval request was still in progress. If the second request was accepted, then the combined peak retrieval rate would have been 10 GB/hr + 11 GB/hr = 21 GB/hr and would exceed the 20 GB/hr Max Retrieval Rate you specified. You decided to wait till the next day to retrieve the 44 GB archive.

On day 5, you learned that the 44 GB archive, along with another 36 GB archive both needed to be available as soon as possible for a customer request. This meant that you needed to retrieve both archives at the same time, equivalent to issuing an 80 GB retrieval request that would yield a 20 GB/hr retrieval rate, which was equal to the “Max Retrieval Rate” you set. You issued both requests and they were both accepted. Your billable peak retrieval rate was (80 GB – 10 GB free tier) / 4 hours = 17.5 GB/hr and your estimated data retrieval cost was 17.5 GB/hr * $0.01 per GB* 720 hours per month = $126.00/month, less than the $144.00/month estimate shown in the AWS console based on a 20 GB/hr Max Retrieval Rate. This new estimate overrides the cost estimate of $54/month on day 3. If you incurred no additional data retrieval cost for the rest of the month, your data retrieval cost for the month would be $126.00, again less than the $144.00/month estimate shown in the console.