How to reslove GRUB prompt error of EC2 server by Raj Gupat

If our EC2 server giving the below error:-

 GNU GRUB version 0.97 (629760K lower / 0K upper memory) [ Minimal BASH-like line editing is supported. For the first word, TAB lists possible command completions. Anywhere else TAB lists the possible completions of a device/filename. ]
grubdom> 

Root Caused:-

If server is Amazon EBS-backed

• Missing GRUB configuration file.
• Incorrect GRUB image used, expecting GRUB configuration file at a different location.
• Unsupported filesystem used to store your GRUB configuration file (for example, converting your root file system to a type that is not supported by an earlier version of GRUB).

If server is Instance store-backed

• Missing GRUB configuration file.
• Incorrect GRUB image used, expecting GRUB configuration file at a different location.
• Unsupported filesystem used to store your GRUB configuration file (for example, converting your root file system to a type that is not supported by an earlier version of GRUB).

Solution:-

A.  If server is Amazon EBS-backed:-

Option 1: Modify the AMI and relaunch the instance: 

1. Modify the source AMI to create a GRUB configuration file at the standard location (/ boot/grub/menu.lst). 

2. Verify that your version of GRUB supports the underlying file system type and upgrade GRUB if necessary. 

3. Pick the appropriate GRUB image, (hd0-1st drive or hd00 – 1st drive, 1st partition). 

4. Terminate the instance and launch a new one using the AMI that you created.

Option 2: Fix the existing instance: 

1. Stop the instance. 

2. Detach the root filesystem. 

3. Attach the root filesystem to a known working instance. 

4. Mount filesystem. 

5. Create a GRUB configuration file. 

6. Verify that your version of GRUB supports the underlying file system type and upgrade GRUB if necessary. 

7. Detach filesystem. 

8. Attach to the original instance. 

9. Modify kernel attribute to use the appropriate GRUB image (1st disk or 1st partition on 1st disk). 10.Start the instance

B. If server is Instance store-backed:-

Option 1: Modify the AMI and relaunch the instance:

1. Create the new AMI with a GRUB configuration file at the standard location (/boot/grub/ menu.lst). 

2. Pick the appropriate GRUB image, (hd0-1st drive or hd00 – 1st drive, 1st partition). 

3. Verify that your version of GRUB supports the underlying file system type and upgrade GRUB if necessary. 

4. Terminate the instance and launch a new instance using the AMI you created.  

Option 2: Terminate the instance and launch a new instance, specifying the correct kernel.

Note :- To recover data from the existing instance, contact AWS Support.