Release: Amazon EC2 on 2010-09-08

Release Notes>Amazon EC2>Release: Amazon EC2 on 2010 09 08
This release introduces the new micro instance type.


Submitted By: cheriaws
Release Date: September 8, 2010 12:00 AM GMT
Latest WSDL:
Created On: September 8, 2010 4:47 PM GMT
Last Updated: September 9, 2010 7:24 PM GMT

New Features

New Instance Type Amazon EC2 now supports a new instance type: micro (t1.micro). Micro instances provide a small amount of consistent CPU resources and allow you to burst CPU capacity when additional cycles are available. They are well suited for lower throughput applications and web sites that consume significant compute cycles periodically.

Micro instances are available on both 32-bit and 64-bit platforms, but only as Amazon EBS-backed instances.

For more information about the new instance type, including appropriate applications for it, go to:

Known Issues

Current Limitations for Micro Instances Following are current limitations of micro instances:
  • They are not available for use with Amazon Virtual Private Cloud
  • They are not available for use with Amazon Elastic MapReduce
  • They are not available for use with Amazon DevPay
Current Limitations for Cluster Compute Instances Following are current limitations of cluster compute instances:
  • They support Linux/UNIX operating systems, but currently not Microsoft Windows Server
  • They are available only in the US-East (Northern Virginia) Region
  • Spot Instance requests for cluster compute instances are not supported
  • They are not available for use with Amazon Virtual Private Cloud
  • They are not available for use with Amazon DevPay
Current Limitations for Cluster Placement Groups Following are current limitations of cluster placement groups:
  • You can't currently use Auto Scaling to launch cluster compute instances into a cluster placement group
  • Reserved Instances are not currently available within a cluster placement group
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 where setting the TCP_MAXSEG socket option on TCP sockets to certain values (known values include 1500) causes the kernel to generate TCP Segmentation Offload (TSO) packets of invalid size that are then dropped by the NIC driver, resulting in very low network throughput. Don't set this socket option and let the kernel handle segmentation and Path Maximum Transmission Unit (PMTU) discovery using the default settings.
Query Version of ModifyInstanceAttribute The Query API ModifyInstanceAttribute request does not allow you to modify the block-device-mappings, and you can't modify the user-data attribute if it already contains data.
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 How to Attach the Volume to an Instance in the Amazon Elastic Compute Cloud User Guide.
Instance limit New users are limited to a maximum of 20 concurrent instances, but many of our customers use hundreds or thousands of instances. If you need a higher limit, go to
©2017, Amazon Web Services, Inc. or its affiliates. All rights reserved.