Release: Amazon EC2 on 2012-07-31

Release Notes>Release: Amazon EC2 on 2012 07 31
This release of Amazon Elastic Compute Cloud (Amazon EC2) introduces a new Amazon Elastic Block Store (EBS) volume type: Provisioned IOPS (input/output operations per second). This release also introduces the ability to launch selected Amazon EC2 instance types as EBS-Optimized instances.


Release Date: August 1, 2012 4:00 AM GMT
Latest Version: 2012-07-20
Latest WSDL:
Created On: August 1, 2012 6:11 AM GMT
Last Updated: August 22, 2012 7:18 PM GMT

New Features

Provisioned IOPS Volumes Provisioned IOPS volumes are designed to meet the needs of I/O-intensive workloads, particularly database workloads, that are sensitive to storage performance and consistency in random access I/O throughput. You specify an IOPS rate when you create the volume, and Amazon EBS provisions that rate for the lifetime of the volume. Amazon EBS currently supports up to 1,000 IOPS per volume, with higher limits coming soon. You can stripe multiple volumes together to deliver thousands of IOPS per instance to your application.

EBS-Optimized Instances EBS optimization enables instances to fully utilize the IOPS provisioned on an Amazon EBS volume. EBS-Optimized instances deliver throughput dedicated to Amazon EBS, with options between 500 Mbps and 1,000 Mbps, depending on the instance type you use. When attached to an EBS-Optimized instance, Provisioned IOPS volumes are designed to deliver within 10 percent of their provisioned performance 99.9 percent of the time in a given year.

Resolved Issues

Issue Resolution
Elastic Network Interfaces Update (April 24, 2012): With Amazon-published Windows Server 2003 AMIs released since 12/27/2011, you can warm attach (when the instance is stopped) and hot attach (when the instance is running) network interfaces to Windows Server 2003 instances.

Version History

Release Date WDSL Description
2012-07-18 2012-06-15.ec2.wsdl Support for high I/O instances (hi1.4xlarge).
2012-07-11 2012-06-15.ec2.wsdl Support for multiple IP addresses for Amazon EC2 instances in Amazon VPC.
2012-06-11 2012-06-01.ec2.wsdl Support for launching an EC2 instance and associating an IAM role with the instance.
2012-06-07 2012-05-01.ec2.wsdl Support for new Spot Instance features that make it easier to get started and handle the potential of interruption. The new features include integration with Auto Scaling and AWS CloudFormation.
2012-05-25 2012-05-01.ec2.wsdl Support for exporting Windows Server instances.
2012-04-26 2012-04-01.ec2.wsdl Support for cc2.8xlarge instances in Amazon VPC.
2012-04-19 2012-04-01.ec2.wsdl Support for the AWS Marketplace.
2012-03-12 2012-03-01.ec2.wsdl Support for volume status and an API version: 2012-03-01.
2012-03-07 2011-12-15.ec2.wsdl Support for 64-bit option for all Amazon Machine Images, a new medium instance type, m1.medium and support for the MindTerm SSH client to allow customers to connect to their Linux instances through a web browser
2011-12-30 2011-12-15.ec2.wsdl Support for Reserved Instance Pricing Tiers and On-Demand price updates
2011-12-30 2011-12-15.ec2.wsdl Support for instance status checks and a new API version.
2011-12-01 2011-12-01.ec2.wsdl Support for New Elastic Network Interfaces (ENIs) for EC2 Instances in a VPCs.
2011-12-01 2011-11-01.ec2.wsdl Support for new choices of Reserved Instance offerings
2011-11-17 2011-11-01.ec2.wsdl Support for the DescribeInstanceStatus API
2011-10-11 2011-07-15.ec2.wsdl Support for EC2 Spot Instances in Amazon VPC
2011-09-15 2011-07-15.ec2.wsdl Support for EC2 VM Import CLI Updates
2011-08-24 2011-07-15.ec2.wsdl VM Import Support for Windows Server 2003 and VHD file format
2011-05-26 2011-05-15.ec2.wsdl Support for Amazon Spot Instances AZ Local Pricing Changes
2011-03-27 2011-02-28.ec2.wsdl Support for Dedicated Instances in a VPC
2011-03-15 2011-01-01.ec2.wsdl Support for Windows Server 2008 R2
2011-03-14 2011-01-01.ec2.wsdl Support for Amazon VPC Internet gateway and updated metadata
2010-12-16 2010-11-15.ec2.wsdl Support for Oracle enterprise applications on Amazon EC2
2010-12-15 2010-11-15.ec2.wsdl Support for VM Import
2010-12-02 2010-08-31.ec2.wsdl Support for Basic Monitoring for EC2 instances
2010-11-14 2010-08-31.ec2.wsdl Support for the new cluster GPU instance type (cg1.4xlarge)
2010-09-28 2010-08-31.ec2.wsdl Support for the AWS SDK for PHP
2010-09-19 2010-08-31.ec2.wsdl Support for tags, filters, idempotent RunInstance calls, and ImportKeyPair
2010-09-08 2010-06-15.ec2.wsdl Support for the new micro instance type
2010-09-02 2010-06-15.ec2.wsdl Support for AWS Identity and Access Management
2010-07-12 2010-06-15.ec2.wsdl Support for the new cluster compute instance type (cc1.4xlarge) and for specifying IP addresses in Amazon VPC
2010-06-14 2009-11-30.ec2.wsdl Support for Amazon CloudWatch monitoring for Amazon EBS volumes
2010-04-28 2009-11-30.ec2.wsdl Support for Asia Pacific (Singapore) Region
2010-03-22 2009-11-30.ec2.wsdl Support for the AWS SDK for Java
2010-02-22 2009-11-30.ec2.wsdl Support for the new High-Memory Extra Large instance type and for Reserved Instances with Windows
2009-12-14 2009-11-30.ec2.wsdl Support for Spot Instances

To view earlier EC2 Release Notes please see EC2.

Known Issues

Current Limitations for VM Import

Following are current limitations of VM Import:

  • The following types of images currently cannot be imported into Amazon EC2:
    • VMware Workstation VMDK images
    • Encrypted, compressed, or read-only images
    • Started or suspended images
    • Linked clones
    • Images with multiple virtual disks
  • When you import a disk image to an Amazon EC2 instance, the instance appears in the AWS Management Console before the conversion process finishes. To determine when the process is complete and the instance is available to use, use the ec2-describe-conversion-tasks command.
Current Limitations for Cluster Instances Following are current limitations of cluster compute and cluster GPU instances:
  • All cluster instance types are available in the US East (N. Virginia) Region. In addition, the cc2.8xlarge instance type is also available in the EU (Ireland) and US West (Oregon) Regions.
  • Amazon DevPay is not supported.
Current Limitations for Cluster Placement Groups Following are current limitations of cluster placement groups:
  • Reserved Instances are not currently available within a cluster placement group
Current Limitations for Tags and Filters You currently cannot tag the following resources:
  • Elastic IP addresses
  • Key pairs
  • Placement groups
You can currently filter your resources in the AWS Management Console by tag, but not by the other filters that are available to use with Describe* actions through the command line tools or API.
Current Limitations for Micro Instances Following are current limitations of micro instances:
  • Amazon Virtual Private Cloud is not supported
  • Amazon Elastic MapReduce is not supported
  • Amazon DevPay is not supported
Setting the TCP_MAXSEG Socket Option The 2.6.18-164.15.1 kernel used in the CentOS 5.4 reference AMI (ami-7ea24a17) contains a known issue: Setting the TCP_MAXSEG socket option on TCP sockets to certain values (e.g., 1500) causes the kernel to generate TCP Segmentation Offload (TSO) packets with invalid sizes that the NIC driver then drops. The impact is significantly lower network throughput. As a workaround, don't set this socket option and let the kernel use the default settings to handle segmentation and Path Maximum Transmission Unit (PMTU) discovery.
Query Version of ModifyInstanceAttribute The ModifyInstanceAttribute action currently does not allow you to modify the block device mapping for the instance.
Paid AMIs Backed by Amazon EBS Amazon EBS-backed AMIs are not currently supported by Amazon DevPay.
Windows AMI Launch Times Windows AMIs take longer to launch than Linux/UNIX instances due to larger AMI sizes and multiple reboots.
Windows AMI Sizes Installing software on Amazon S3-backed Windows AMIs can cause them to become large and easily reach the 10 GB limit. Before bundling, check the size of the C:\ volume.
Limitation on Drive Mapping There are limitations on devices available for storage attachment. For more information, go to Attaching the Volume to an Instance in the Amazon Elastic Compute Cloud User Guide.
Instance Limit New AWS accounts are limited to a maximum of 20 concurrent instances (of which 2 may be CG1 instances), but many of our customers use hundreds or thousands of instances. If you need a higher limit, go to Request to Increase Amazon EC2 Instance Limit (
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