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Use M3 Instances

This is documentation for AWS M3 instances. This new generation of EC2 instances provides high frequency processors and offer SSD-based instance storage for fast instance store I/O performance.

General Purpose (M3)

The 64-bit instance types, available in all AWS regions, and optionally as dedicated instances, are:

  • Medium
  • Large
  • Extra Large*
  • 2x Extra Large* Hidden behind feature flag

* Extra large and double extra large instances are also available as EBS optimized instances.

Get started with M3 instances on Engine Yard

This document describes how to use M3 instances with Engine Yard.


  • This article assumes you already have an Engine Yard account. If not, see Sign up for an Engine Yard Account.
  • You must add a new instance to use this feature. You cannot modify an existing instance / volume.
  • You must use 64-bit instances (32-bit instances are not supported).
  • If you are using the Engine Yard Gentoo 2009 stack, you must click Update for the April 3, 2014 stable-v2 stack upgrade to gain M3 instances support.
  • If you are using the Engine Yard Gentoo 12.11 stack, you must click Update for the April 3, 2014 stable-v4 stack upgrade to gain M3 instances support.

Configure M3 instances

You can configure M3 instances when you add new instances to a new or existing environment.

Note: We recommend testing in a staging environment before applying changes in a production environment.

To add a new M3 instance

  1. Ensure that you meet all the prerequisites above.

  2. Add an instance in the usual way.

    See the database docs for more information about adding a database instance to an environment.

  3. Select the appropriate General Purpose M3 instance size in the list.



    • Some instance sizes may not be available by default. Please contact Engine Yard Support if you do not see the necessary instance sizes.
    • Dedicated instances might not appear if you have had an Engine Yard account for awhile. See the notes in More information.
  4. Click Add to Cluster (or Boot This Configuration, if you are re-booting an existing environment).

    See the related documentation for more information on adding instances to your environment.

    Note: If you are adding a M3 database instance, you also need to click Apply to update the database.yml file.

Verify M3 instances

Note: When you are testing in staging, consider the differences between your test and production loads.

To verify M3 instances

  1. Ensure that instance provisioning worked and the instance is running.

    In general, that is enough of an indication that the M3 instance is working fine.

  2. Review the Troubleshooting tips below for more information.
  3. If this is a staging environment and you are finished with testing, be sure and stop any M3 instances to avoid unnecessary charges.
  4. Stop any unneeded M3 instances to avoid unnecessary charges.


You might have these questions about M3 instances.

How can I use the SSDs on these instances?

You can leverage the SSDs as needed via custom Chef; be aware that there is no ability to create snapshots of SSDs.

How much does it cost?

See the pricing page for details.


This table contains troubleshooting tips related to M3 instances.

The M3 dedicated instances do not appear in the drop-down list. If you have had an Engine Yard account for a while, you might need to create a new Engine Yard account in order to use the dedicated instances feature in your region. This is because it is part of the AWS default VPC feature set. Check the AWS "default VPC" region release dates or contact Engine Yard Support if you need help. See the dedicated instances doc and this note for more information.
When I clicked HTTP on the app server, I received a 500 Internal Server Error. If this is the first time provisioning, wait a few minutes and try again.

More information

This table provides other resources related to M3 instances.

For more information about...See...
Adding an instance to an environment Add Instances to an Environment
Adding a database instance to an environment Add a database replica (slave) to an existing environment
EBS optimized instances EBS optimized instances
Dedicated instances Dedicated instances

If you have feedback or questions about this page, add a comment below. If you need help, submit a ticket with Engine Yard Support.

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  • Avatar
    Fernando Calatayud

    How much does it cost? The pricing page doesn't say nothing about M3 instances, and with the C3 pricing your margin raised a lot for the same services


  • Avatar
    Tasha Drew

    Hi Fernando, 

    Here are our current prices for M3s. To anyone reading this in the future, please check out http://www.engineyard.com/pricing to be sure you're seeing the latest prices.

    BoxUsage:m3.medium  $0.14 

    BoxUsage:m3.large  $0.25 

    BoxUsage:m3.xlarge  $0.45 

    BoxUsage:m3.2xlarge  $0.81 

    DedicatedUsage:m3.medium  $0.15 

    DedicatedUsage:m3.large  $0.28 

    DedicatedUsage:m3.xlarge  $0.49 

    DedicatedUsage:m3.2xlarge  $0.89 

    Also, our website pricing page is about to be fully updated with all the C3 and M3 pricing info.


  • Avatar
    Mikel Kew

    FYI: It mentions "You can leverage the SSDs as needed via custom Chef" for both m3 and c3 instances. To save time for those looking how to do this, there is a little more to it... SSD support must be enabled by EY support as a feature flag for the environment/account, and can be requested via a support ticket.

  • Avatar
    Tasha Drew

    Hi Mikel, 


    Thanks for the note! 

    SSD support is not behind a feature flag, although it does require custom chef. 

    You may be recalling when M3/C3 instances were behind a feature flag and in early access? They have now been GA'd and are available directly from the drop down without enabling a flag.

    Thanks, Tasha 

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