Ubuntu – EC2 instance ssh connection not working

amazon ec2fstabsshUbuntu

I tried to connect to my EC2 Ubuntu LTS instance but I failed.
The error message I got like below:
ssh: connect to host ec2-79-125-83-13.eu-west-1.compute.amazonaws.com port 22: Connection refused

I checked the instance log, the last lines like below:

The disk drive for /dev/xvdf is not ready yet or not present. 
Continue to wait, or Press S to skip mounting or M for manual recovery

What could be the problem here?

Could you help me please?

Best Answer

Probably an /etc/fstab issue. Ubuntu is trying to mount a partition present in /etc/fstab and yet not able to find that partition i.e. /dev/xvdf.

In order to troubleshoot this, you need to -

1) shutdown this instance

2) Launch another instance

3) Attach the root EBS of this instance to the new instance from step(2)

4) mount the EBS from step(3) , say in /mnt/ebs

5) Check fstab for any inconsistency , /mnt/ebs/etc/fstab. If there is any inconsistency, backup that file, modify it, unmount the partition, and re-attach it to the instance in step(1) and launch it.

Related Solutions

SSH – Bad Owner or Permissions on ~/.ssh/config

I needed to have rw for user only permissions on config. This fixed it.

chmod 600 ~/.ssh/config

As others have noted below, it could be the file owner. (upvote them!)

chown $USER ~/.ssh/config

If your whole folder has invalid permissions here's a table of possible permissions:

Path	Permission
.ssh directory (code)	0700 (drwx------)
private keys (ex: `id_rsa`) (code)	0600 (-rw-------)
`config`	0600 (-rw-------)
public keys (*.pub ex: `id_rsa.pub`)	0644 (-rw-r--r--)
`authorized_keys` (code)	0644 (-rw-r--r--)
`known_hosts`	0644 (-rw-r--r--)

Sources:

openssh check-perm.c
openssh readconf.c
openssh ssh_user_config fix_authorized_keys_perms

SSH login fails for EC2 instances created from image of working EC2

I suspect this is an SELinux problem. Check the context of the folder you are using, I expect it won't be correct for holding keys.

Im afraid I no longer have access to a Redhat box to establish exactly what the context should be. That said, try this:

ls -lZ /root/.ssh

This will yield the selinux context that your new folder needs to be. If I remember correctly it should be something like system_u:system_r:sshd_t

Then we need to apply that security context to your new authorized keys location:

semanage fcontext -a -t system_u:system_r:sshd_t “/etc/ssh/keys(/.*)?”

Which associated the correct context with the new keys location. Finally, we can apply the context to the new location

restorecon -Rv /etc/ssh/keys

Best Answer

Related Solutions

SSH – Bad Owner or Permissions on ~/.ssh/config

SSH login fails for EC2 instances created from image of working EC2

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