Instance reachability check failed.

Question

We set up an EC2 instance (SLES 15) for an ERP sandbox more than a month ago and just decided to create an EC2 instance scheduler to stop and start the instance on a predefined schedule.  The instance scheduler functioned as expected, but the EC2 instance reported a check failure "Instance reachability check failed" under Instance Status Checks.
![Instance reachability check failed](/media/postImages/original/IM5nPYk1iNQgiqkCDBk8PsSA)

We tried to investigate further but were unable to connect via SSH, stopped and restarted the instance with no luck, and tried the EC2 serial interface to get into the instance but it requested the root password, which we had not set in the first place.
![EC2 Serial Console](/media/postImages/original/IMM2FstCFnQ8mTUhLEGJvs5A)

I wanted to attach the logs here but couldn't find a way, so I'll simply provide a link:
[https://drive.google.com/file/d/1Oebr7Cw8uqbeCwqQR2KjpBjbf0k0p2xe/view?usp=sharing]()

Please excuse my lack of technology experience, but I would want to ask the community if there are any other solutions we may try to address this problem.

Thanks.

Accepted Answer

Hello.

Looking at the log, it appears that EBS is not being accessed properly as shown below.  
Did you change any settings in "/etc/fstab" etc. before the error occurred?  
```
 [K[ [0;1;31m TIME  [0m] Timed out waiting for device  [0;1;39m/dev/nvme1n1p1 [0m.
 [K[ [0;1;38;5;185mDEPEND [0m] Dependency failed for  [0;1;39m/hana/data [0m.
[ [0;1;38;5;185mDEPEND [0m] Dependency failed for  [0;1;39mLocal File Systems [0m.
[ [0;1;38;5;185mDEPEND [0m] Dependency failed for  [0;1;39mEarly Kernel Boot Messages [0m.
[ [0;1;31m TIME  [0m] Timed out waiting for device  [0;1;39m/dev/nvme1n1p4 [0m.
[ [0;1;38;5;185mDEPEND [0m] Dependency failed for  [0;1;39m/usr/sap [0m.
[ [0;1;31m TIME  [0m] Timed out waiting for device  [0;1;39m/dev/nvme1n1p2 [0m.
[ [0;1;38;5;185mDEPEND [0m] Dependency failed for  [0;1;39m/hana/log [0m.
[ [0;1;31m TIME  [0m] Timed out waiting for device  [0;1;39m/dev/nvme1n1p3 [0m.
[ [0;1;38;5;185mDEPEND [0m] Dependency failed for  [0;1;39m/hana/shared [0m.
[ [0;32m  OK   [0m] Stopped  [0;1;39mDispatch Password …ts to Console Directory Watch [0m.
[ [0;32m  OK   [0m] Reached target  [0;1;39mTimer Units [0m.
[ [0;32m  OK   [0m] Reached target  [0;1;39mCloud-init target [0m.
         Starting  [0;1;39mRestore /run/initramfs on shutdown [0m...
```

If you have changed the settings, please create a rescue EC2 and troubleshoot according to the document below.  
https://repost.aws/knowledge-center/ec2-linux-emergency-mode

Instance reachability check failed.

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