1) Compute Instance

1. Unable to connect to Instance using SSH

Issue :- Unable to connect to Instance using SSH during instance creation

Root Cause :- Private SSH key was not saved during instance creation

Solution :- Downloaded both Public and Private SSH keys. I was able to successfully create the compute instance.

2. "Out of capacity" error for a specific shape

Issue :- "Out of capacity" error for a specific shape in the selected Availability domain and the fault domain, during instance creation

Root Cause :- There is not enough capacity for the listed shape in the selected Availability domain and the fault domain

Solution :- As suggested in the error message, created the instance without specifying a fault domain

3. "Target is busy" error while unmounting mounted volume

Issue :- "Target is busy" error is coming while trying to unmount a mounted volume in the server

Root Cause :- There is a process id attached to the mounted volume, which is preventing it from getting unmounted.

Solution :- The process id needs to be deleted after confirmation from the application team. Once deleted, the mount volume can be unmounted

4. Root login failed post Boot volume attachment to New Instance

Issue :- Unable to login to Root user with password, after attaching the Boot volume to the New Instance

Root Cause :- In /etc/ssh/sshd_config file, PasswordAuthentication parameter is set to No

Solution :- In /etc/ssh/sshd_config file, set "PasswordAuthentication yes". After that, login to Root user with password is successful.

4. Unable to login to New Instance as SSH keys lost

Issue :- Unable to login to Root user with password, after attaching the Boot volume to the New Instance

Root Cause :- In /etc/ssh/sshd_config file, PasswordAuthentication parameter is set to No

Solution :- In /etc/ssh/sshd_config file, set "PasswordAuthentication yes". After that, login to Root user with password is successful.

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2) VCN

1. Unable to see Subnets after VNC creation

Issue :- Unable to see Subnets(Public and Private) after VNC creation

Root Cause :- VCN was created in the incorrect compartment

Solution :- Old VCN deleted. Created New VCN in the correct compartment - NetworkCompartment. Both Subnets(Public and Private) are now visible after VNC creation

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5. Getting Connection timed out when connecting to any instance through Putty.

Root Cause :- In the Security List for the VCN, Ingress rule was set for the Old IP of the user system

Solution :- Update the Ingress rule with the current IP of the user system