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Naruto Uzumaki
Asked: 2024-09-30 05:23:04 +0800 CST

Can't log in after changing default port 22 on Oracle Cloud VM Ubuntu Server

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I recently set up a virtual server on Oracle Cloud using Ubuntu. I wanted to enhance security by changing the default SSH login port from 22 to 777 (or any random port). So, I went into /etc/ssh/sshd_config and changed the Port 22 setting. Now, I’m unable to log back in via SSH, whether I try using the new port or the old one.

So can't use any commands... only the dashboard... which is a struggle in itself.

I’m using PuTTY for SSH access and have already contacted Oracle Cloud support. Unfortunately, their response was... unhelpful/useless/waste of time(to put it mildly) — they essentially just pointed me to basic Google search results, which I had already tried without success.

Has anyone else experienced this issue on Oracle Cloud’s free tier, or does anyone have advice on how to fix this? I didn’t take a backup (I know, my mistake, already feeling beyond stupid), and I really need to recover some important data from the server. Any suggestions would be greatly appreciated!

server

1 Answers

  1. Best Answer

    I found a solution to my problem, which involves using Oracle Cloud Shell to run commands directly. Here’s the process:

    1. First, create a backup of the boot volume.
    2. Next, detach the boot volume from the instance.
    3. Delete the instance, but ensure that the boot volume is saved and kept safe. All of this can be done through the Oracle Cloud dashboard.
    4. Now, create a new instance.
    5. Once the new instance is up and running, go to Cloud Shell and enter the following command:
    oci compute volume-attachment attach \
    --instance-id <target_instance_ocid> \
    --volume-id <boot_volume_ocid> \
    --type paravirtualized \
    --display-name "BootVolumeAsBlock"

    Replace <target_instance_ocid> with the new instance OCID and <boot_volume_ocid> with the OCID of the old boot volume (The one you were locked out of), which can be found in the Oracle Cloud dashboard. When you run this command, it will successfully attach the boot volume to your new instance.

    After that, simply mount the old boot volume to a directory, and you’ll be able to access all its files and folders, make changes, or retrieve any data.

    To do this follow these steps to access its files: (These commands are to be run on after connecting to the new instance you made and not in Oracle Cloud Shell like earlier commands)

    1. Run lsblk to list devices and find the new volume (e.g., /dev/sdb).
    2. Use sudo mkdir /mnt/boot-volume to create a directory.
    3. Mount the volume with sudo mount /dev/sdb1 /mnt/boot-volume.
    4. Navigate to the mount point (cd /mnt/boot-volume) and list files (ls).
    5. You can also join from filezilla and go to the directory you created to download anything from old volume.

    This method works if you've lost your SFTP key, forgotten your password, or are unable to access the instance for any other reason. Good luck!

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