Instance reachability check failed


This is one error you do not want to see when you are booting up an EC2 instance the dreaded

Instance reachability check failed. Pass 0/2 checks or 1/2 check. Especially when this is you backup copy of a live system.

Believe me when I tell you that this strategy is being changed very quickly and S3 will be used for backup sets.

So how the hell do you fix this issue. Well if you are in the following situation all may not be lost.

This is based on the Ec2 instance being EBS backed if it is S3 then sorry not sure how you will get it working.

This method will allow you to get you data from the system and then allow you to rebuild the server, e.g. apache webserver.

This has worked on a Linux server, I have not tried it on a Windows server but it should work. Hopefully I will nerver have to try 🙂

Start by creating  a disk volume from the snapshot

When the dialogue shows enter the details in terms of size. I made the volume the same size as the snapshot.

Make a note of the zone as you will need to launch an instance in this zone.

Yes to create the Volume.

Now Launch a new instance in the zone when the volume was created, this is where the micro instance come into their own. Once this is operational you need to attach the newly created volume to the instance.

Navigate to the volume screen and pick the volume, at the top of the screen use the drop down box to display Attach Volume and pick the newly created instance.

This will attach the volume to the server.

Log-on to the server, since this is Linux you need to mount the disk.

To make this complete and just in case you are a bit rusty, this is how you do this.

fdisk -l

will give you an output something like this

Disk /dev/xvda1: 8589 MB, 8589934592 bytes
255 heads, 63 sectors/track, 1044 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x00000000

Disk /dev/xvda1 doesn’t contain a valid partition table

Disk /dev/xvdf: 8589 MB, 8589934592 bytes
255 heads, 63 sectors/track, 1044 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Sector size (logical/physical): 512 bytes / 512 bytes

I/O size (minimum/optimal): 512 bytes / 512 bytes

Disk identifier: 0x00000000

Disk /dev/xvdf doesn’t contain a valid partition table

The important line is the /dev/xvdf – this indicated the mounted volume

To mount the volume, as root (sudo su)

cd /

mkdir u10

mount -t ext4 /dev/xvfd /u10 

Note if you get an error regarding the format change to ext3 or another disk format, but this should work.

 

You can now cd into u10 and you have access to the file system.

 

Good luck if this has happened to you

 

Alistair

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2 Comments on “Instance reachability check failed”

  1. sai.pathi6 says:

    Hi
    I taken a space in AWS AMAZON. As per my client request, installing Active Directory in that machine. i connected remotely to that system , trying to installing active directory. But unfortunately i changed the ip address and , subnet mask and Dns in that system (where i connected in remotely , cloud system), immediately its disconnected. And i am unable to connect to it in remote. i went to that website and login , the server os is running and its hows the “instance failure” message. but its showing the os is running. How can i start my system, please help me. if any one give phone number , i will explain it.
    please help me .


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