[ec2] Can't contact instance

Eric Hammond ehammond at thinksome.com
Wed Aug 5 04:26:31 BST 2009


Almost everything I know about building Ubuntu AMIs is in code form in

There should be a few minor changes if you are running on the Canonical
kernels (e.g., kernel modules) but if you go through this code something
there might trigger an idea to test.

You don't need to set up /etc/hostname or set any hostname in /etc/hosts
other than the usual "localhost".  DHCP can set the regular hostname for
you using info from Amazon.

Eric Hammond
ehammond at thinksome.com

Tom Haddon wrote:
> On Tue, 2009-08-04 at 15:23 -0700, Eric Hammond wrote:
>> Tom:
>> I had, perhaps incorrectly, assumed you built your AMI by rebundling a
>> running instance of a public AMI.
>> Did you build your AMI from scratch using vmbuilder,
>> ec2ubuntu-build-ami, or by hand?
> I built it from scratch. 
>> There are various EC2 specific boot tasks that need to be taken care of
>> without which you cannot connect to the instance.
> Yeah, the ones that I'd been doing were working fine on my i386 images,
> just things didn't seem to be working for this amd64 image (the first
> I'd created). Basically my process was:
> - Create a sparse file
> - Mount the sparse file as a loopback device (let's say it's mounted at
> dir_name)
> - debootstrap --arch amd64 hardy dir_name
> - In the chroot:
>  - add /sbin/ldconfig to /etc/rc.local
>  - create /etc/ld.so.conf.d/xen.conf with: hwcap 0 nosegneg
>  - add /etc/init.d/ec2-ssh-host-key and run update-rc.d per
> http://paste.ubuntu.com/247568/
>  - add my own user accounts/ssh authentication/sudo setup
>  - any other setup/packages you want for the particular AMI
> - bundle and upload to AWS
> I think there may have been a mismatch between /etc/hosts
> and /etc/hostname - I've fixed that and will be re-uploading the image
> and trying again.
> Thanks, Tom
>> --
>> Eric Hammond
>> ehammond at thinksome.com
>> Tom Haddon wrote:
>>> On Mon, 2009-08-03 at 19:44 -0700, Eric Hammond wrote:
>>>> Tom:
>>>> Right about the time you reported this, a higher than usual number of
>>>> other people reported similar problems on the EC2 forum.  There may have
>>>> been a localized networking or systems issue.
>>>> Amazon's AWS status board has not shown any problems at this point, so
>>>> it may have been temporary or isolated.
>>>> I would recommend trying to start new instances, perhaps in multiple
>>>> availability zones, to see if the problem is really with your AMI or the
>>>> environment.
>>> I tried starting instances of the AMI in all four availability zones and
>>> none of the instances were contactable. I'm going to try comparing my
>>> AMI with the stock ubuntu amd64 hardy AMI and see if I can see any major
>>> differences.
>>> Thanks, Tom
>>>> --
>>>> Eric Hammond
>>>> ehammond at thinksome.com
>>>> Tom Haddon wrote:
>>>>> Hi Folks,
>>>>> I'm getting a very strange issue with a particular AMI I've created.
>>>>> It's a x86_64 image, and I'm using the stock Ubuntu AKI/ARI
>>>>> (aki-6f709706/ari-61709708). I start an instance of my AMI and get the
>>>>> following console output:
>>>>> http://paste.ubuntu.com/246739/
>>>>> I can't login to the instance, or contact it via ping, even though:
>>>>> http://paste.ubuntu.com/246741/
>>>>> Any ideas what could be going on? From what I can see of the console
>>>>> output the machine has booted okay, but then I just can't contact it at
>>>>> all...
>>>>> Thanks, Tom

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