Move a Running EBS Boot Instance to New Hardware on Amazon EC2


NOTE: Though this method works and there is useful information in this article about things you can do with EBS boot instances, there is a simpler way to move an instance to new hardware.

Amazon EC2 has been experiencing some power issues in a portion of one of their many data centers. Even though the relative percentage of people affected might be small, when you have as many customers as AWS does, a small fraction can still be a large absolute number of customers who are affected.

Naturally, some customers will be upset about not having access to their systems, but in the time it takes to write a complaint, you might be able to move your server to new hardware within EC2 and go on with your business

First, lets assume that you are running an EBS boot instance. If you didn’t think they were the way to go before reading this article, I expect to convince you with this one example (and there are a number of other benefits).


For this demo, I’m going to start an instance. In your situation this instance represents the currently running server that you are depending on and which has valuable software, configuration, and perhaps data on its EBS volume(s). I’m also going to drop a note on the EBS root disk on my running instance so that I know it is the one I wanted to preserve. Again, this is just setting things up for the demo:

sshkey=.ssh/$keypair.pem # or wherever you keep it
region=us-west-1 # pick your region
zone=${region}a # pick your availability zone
type=m1.small # pick your size
amiid=ami-cb97c68e # Ubuntu 10.04 Lucid, 32-bit, EBS boot in that region
oldinstanceid=$(ec2-run-instances   --key $keypair   --region $region   --availability-zone $zone   --instance-type $type   $amiid |
  egrep ^INSTANCE | cut -f2)
echo "instanceid=$oldinstanceid"

while host=$(ec2-describe-instances --region $region "$oldinstanceid" | 
  egrep ^INSTANCE | cut -f4) && test -z $host; do echo -n .; sleep 1; done
echo host=$host

echo "save the volume" | ssh -i $sshkey ubuntu@$host tee README.txt

Moving to a New Instance

Now, we pretend that the above created instance has failed in some way and we can no longer access it. Here’s how we get our server running on a new instance:

  1. If you can, stop the old instance. This increases your chance of keeping the file system consistent on the EBS volume. If the instance has really failed and this step does not work, then skip it.

    ec2-stop-instances --region $region $oldinstanceid
  2. Run a new instance with the same startup parameters as your old instance.

    newinstanceid=$(ec2-run-instances   --key $keypair   --region $region   --availability-zone $zone   --instance-type $type   $amiid |
      egrep ^INSTANCE | cut -f2)
    echo "newinstanceid=$newinstanceid"
  3. Wait until the new instance is running and then stop (not terminate) the new instance and detach the EBS boot volume from it. Delete the volume as it has nothing of importance, having just been created.

    ec2-stop-instances --region $region $newinstanceid
    newebsroot=$(ec2-describe-instances --region $region $newinstanceid |
      grep ^BLOCKDEVICE | grep /dev/sda1 | cut -f3)
    ec2-detach-volume --force --region $region $newebsroot
    ec2-delete-volume --region $region $newebsroot
  4. Detach the old (valuable) EBS root volume from the old (broken) instance.

    oldebsroot=$(ec2-describe-instances --region $region $oldinstanceid |
      grep ^BLOCKDEVICE | grep /dev/sda1 | cut -f3)
    ec2-detach-volume --force --region $region $oldebsroot
  5. Attach the old (valuable) EBS root volume to the new (stopped) instance.

    ec2-attach-volume   --region $region   -d /dev/sda1   -i $newinstanceid   $oldebsroot

    If you had multiple EBS volumes attached to the old instance, you would move each one over in a similar manner.

  6. Restart the new instance which is now going to boot with the original volume.

    ec2-start-instances --region $region $newinstanceid

Voila! You have moved your server from an old, perhaps broken instance to new (or at least different) hardware keeping the same file system, and it took only a few minutes! If you’d like, ssh to the new instance and make sure that your valuable information is still there.

If you had an Elastic IP address associated with the old instance, you would move it to the new instance.


You may terminate the old instance if you are comfortable that you won’t need it any more. If you were following this demo as an exercise, you should also terminate the new instance. Since you manually attached the old volume to the new instance yourself, it will not be deleted automatically when the instance is terminated. You can modify the instance attributes to change the delete-on-termination flag for the volume or simply delete it manually.

# BEWARE! Don't copy these blindly, but think about what you should do
ec2-terminate-instances --region $region $oldinstanceid
ec2-terminate-instances --region $region $newinstanceid
ec2-delete-volume --region $region $oldebsroot


This above process can also be used when your instance is running fine, but you want to move to a different instance type (size) of the same architecture. For example, you could move from m1.small up to c1.medium, or from m2.4xlarge down to c1.xlarge. Update: I wasn’t thinking clearly when I wrote that last sentence. It is possible to change the instance type much more easily: Simply stop the instance, use ec2-modify-instance-attribute, and start it up again. Read more about this method.

You can also resize the root disk of a running EC2 instance using the same basic principle of swapping out an EBS root volume on a running instance.

[Update 2011-02-07: Point out simpler method to move to new hardware.]
[Update 2012-01-08: Link to article on changing instance type.]


As tested by Twitter user @schmidtcw, this technique works for Windows instances as well.

Instead of going to the trouble of creating a new instance and moving the boot volume, can't you just stop the old instance, change the instance type, and restart? It seems that should move you to new hardware even faster?

You should also note that bot of these processes will lose all the data on your ephemeral disks.


Tom: Yes, I caught this myself and updated the document before I received your comment, but thanks for pointing it out. Your observation on the local storage is also a good one. I tend not to think about it much since most everything I do is on EBS volumes these days.

Impecable timing. I received a notice yesterday about a hardware failure on one of my instances. Thanks to all your other tutorials and this helpful reminder, I was up and running on a different instance in no time.

The only catch for me was that I couldn't get the instance to stop, not could I detach the volumes. Fortunately I was able to create snapshots and go from there.

jedwood: ec2-detach-volume --force usually gets the job done, but I have seen cases where hardware failure prevents detaching. If you go the snapshot route, it might be easier to just register the snapshot as a new AMI and run an instance of it. My approach above (transferring the volume without a snapshot) is optimized for time to recovery, but snapshot AMIs are a bit easier.

As per my earlier comment, I am running a drupal site on an EBS Lucid instance. When I try to relaunch an AMI created from the original instance, nothing works - apache is not running, nor is mysql etc... Would it be because its still transferring data from s3?

I can't debug your issue from here, but if you post complete instructions on how to reproduce your problem to somebody might have some ideas.

Hi Eric,

I did the dry run of your steps here. If I am able to stop the system than, I can detach all EBS volumes including Root vol. But, if I am not stopping the system, I am able to only detach non-root EBS vols which makes sense.

So, If I have a system which suddenly becomes inaccessible and I am not able to stop the system, I should be able to detach the non-root EBS volumes. Than, I can fire a new system with my private root partition image and attach this non-root volumes to the new system.

In case I am not able to detach any of the volumes, than we need to recover from snapshots of EBS volumes. The only issue here is that the system can not be used for production due to poor response time till all the blocks are copied from snapshots which can take upto 4-5 hrs for a 500GB vol.

Is there any better way to recover quickly if you are not able to salvage your EBS vols from inaccessible/hosed/failed system ?



anil: If you set up the root EBS volume to persist after instance termination, then you might be able to terminate the instance and force detach the EBS root volume.

If your project requires rapid recovery times, you might want to keep a hot spare standing by, updating live from the master, and ready for a fast failover, perhaps even automated.

This doesn't seem to work for me. I'm able to get as far as attaching the old volume to the new instance - the instance even shows the root device /dev/sda1 as being attached to the volume. Booting the instance leaves it in "running" state, however sshd now rejects all connections. Sadface.

If you're moving to a t1.micro using the current Ubuntu 10.04 AMIs, you'll need to first apply a workaround as described in

The fix for this bug is in the process of being released, but in the meantime we need to manually account for the fact that t1.micro do not have ephemeral store.

This works perfect, I was also able to use a modified approach to this steps (simply by creating a snapshot of the old EBS and then spawning a new volume in the proper zone) to "move" an instance from one availability zone to another one (useful for the classic mistake when purchasing a reserved instance in a different AZ...)

Hi Eric, thank you for this post. I discovered that its possible to do a lot of these steps directly in the AWS control panel (which might be easier for some users).

Boris: Yep. Most of the steps I describe using AWS command line tools can be done through the AWS console, third party web UIs, or through direct API calls in your favorite programming language. I prefer demonstrating with command line examples so folks can copy and paste, and because it is easier to automate procedures with commands or the corresponding direct API calls.


Nice idea, thanks!

Leave a comment

Ubuntu AMIs

Ubuntu AMIs for EC2:

More Entries

When Are Your SSL Certificates Expiring on AWS?
If you uploaded SSL certificates to Amazon Web Services for ELB (Elastic Load Balancing) or CloudFront (CDN), then you will want to keep an eye on the expiration dates and…
Throw Away The Password To Your AWS Account
reduce the risk of losing control of your AWS account by not knowing the root account password As Amazon states, one of the best practices for using AWS is Don’t…
AWS Community Heroes Program
Amazon Web Services recently announced an AWS Community Heroes Program where they are starting to recognize publicly some of the many individuals around the world who contribute in so many…
EBS-SSD Boot AMIs For Ubuntu On Amazon EC2
With Amazon’s announcement that SSD is now available for EBS volumes, they have also declared this the recommended EBS volume type. The good folks at Canonical are now building Ubuntu…
EC2 create-image Does Not Fully "Stop" The Instance
The EC2 create-image API/command/console action is a convenient trigger to create an AMI from a running (or stopped) EBS boot instance. It takes a snapshot of the instance’s EBS volume(s)…
Finding the Region for an AWS Resource ID
use concurrent AWS command line requests to search the world for your instance, image, volume, snapshot, … Background Amazon EC2 and many other AWS services are divided up into various…
Changing The Default "ubuntu" Username On New EC2 Instances
configure your own ssh username in user-data The official Ubuntu AMIs create a default user with the username ubuntu which is used for the initial ssh access, i.e.: ssh ubuntu@<HOST>…
Default ssh Usernames For Connecting To EC2 Instances
Each AMI publisher on EC2 decides what user (or users) should have ssh access enabled by default and what ssh credentials should allow you to gain access as that user.…
New c3.* Instance Types on Amazon EC2 - Nice!
Worth switching. Amazon shared that the new c3.* instance types have been in high demand on EC2 since they were released. I finally had a minute to take a look…
Query EC2 Account Limits with AWS API
Here’s a useful tip mentioned in one of the sessions at AWS re:Invent this year. There is a little known API call that lets you query some of the EC2…
Using aws-cli --query Option To Simplify Output
My favorite session at AWS re:Invent was James Saryerwinnie’s clear, concise, and informative tour of the aws-cli (command line interface), which according to GitHub logs he is enhancing like crazy.…
Reset S3 Object Timestamp for Bucket Lifecycle Expiration
use aws-cli to extend expiration and restart the delete or archive countdown on objects in an S3 bucket Background S3 buckets allow you to specify lifecycle rules that tell AWS…
Installing aws-cli, the New AWS Command Line Tool
consistent control over more AWS services with aws-cli, a single, powerful command line tool from Amazon Readers of this tech blog know that I am a fan of the power…
Using An AWS CloudFormation Stack To Allow "-" Instead Of "+" In Gmail Email Addresses
Launch a CloudFormation template to set up a stack of AWS resources to fill a simple need: Supporting Gmail addresses with “-” instead of “+” separating the user name from…
New Options In ec2-expire-snapshots v0.11
The ec2-expire-snapshots program can be used to expire EBS snapshots in Amazon EC2 on a regular schedule that you define. It can be used as a companion to ec2-consistent-snapshot or…
Replacing a CloudFront Distribution to "Invalidate" All Objects
I was chatting with Kevin Boyd (aka Beryllium) on the ##aws Freenode IRC channel about the challenge of invalidating a large number of CloudFront objects (35,000) due to a problem…
Email Alerts for AWS Billing Alarms
using CloudWatch and SNS to send yourself email messages when AWS costs accrue past limits you define The Amazon documentation describes how to use the AWS console to monitor your…
Cost of Transitioning S3 Objects to Glacier
how I was surprised by a large AWS charge and how to calculate the break-even point Glacier Archival of S3 Objects Amazon recently introduced a fantastic new feature where S3…
Running Ubuntu on Amazon EC2 in Sydney, Australia
Amazon has announced a new AWS region in Sydney, Australia with the name ap-southeast-2. The official Ubuntu AMI lookup pages (1, 2) don’t seem to be showing the new location…
Save Money by Giving Away Unused Heavy Utilization Reserved Instances
You may be able to save on future EC2 expenses by selling an unused Reserved Instance for less than its true value or even $0.01, provided it is in the…
Installing AWS Command Line Tools from Amazon Downloads
This article describes how to install the old generation of AWS command line tools. For the most part, these have been replaced with the new AWS cli that is…
Convert Running EC2 Instance to EBS-Optimized Instance with Provisioned IOPS EBS Volumes
Amazon just announced two related features for getting super-fast, consistent performance with EBS volumes: (1) Provisioned IOPS EBS volumes, and (2) EBS-Optimized Instances. Starting new instances and EBS volumes with…
Which EC2 Availability Zone is Affected by an Outage?
Did you know that Amazon includes status messages about the health of availability zones in the output of the ec2-describe-availability-zones command, the associated API call, and the AWS console? Right…
Installing AWS Command Line Tools Using Ubuntu Packages
See also: Installing AWS Command Line Tools from Amazon Downloads Here are the steps for installing the AWS command line tools that are currently available as Ubuntu packages. These include:…
Ubuntu Developer Summit, May 2012 (Oakland)
I will be attending the Ubuntu Developer Summit (UDS) next week in Oakland, CA. ┬áThis event brings people from around the world together in one place every six months to…
Uploading Known ssh Host Key in EC2 user-data Script
The ssh protocol uses two different keys to keep you secure: The user ssh key is the one we normally think of. This authenticates us to the remote host, proving…
Seeding Torrents with Amazon S3 and s3cmd on Ubuntu
Amazon Web Services is such a huge, complex service with so many products and features that sometimes very simple but powerful features fall through the cracks when you’re reading the…
There are a number of CloudCamp events coming up in cities around the world. These are free events, organized around the various concepts, technologies, and services that fall under the…
Use the Same Architecture (64-bit) on All EC2 Instance Types
A few hours ago, Amazon AWS announced that all EC2 instance types can now run 64-bit AMIs. Though t1.micro, m1.small, and c1.medium will continue to also support 32-bit AMIs, it…
ec2-consistent-snapshot on GitHub and v0.43 Released
The source for ec2-conssitent-snapshot has historically been available here: ec2-consistent-snapshot on using Bazaar For your convenience, it is now also available here: ec2-consistent-snapshot on GitHub using Git You are…