Himanshu Sinha - Oracle Apps DBA , Oracle DBA, Oracle Cloud DBA , Enterprise Architect.

Recovering opc user SSH Key on OCI ===================================== Today i came across the situation where my colleague has created UNIX instance on oci and then she lost opc user private keys.  Due to that she was not able to login to that instance and no one has access to this instance as well. It can happen with any one who is trying to connect into their Oracle Cloud Infrastructure instance but either you forgot which key you used or, for some unknown reason, your opc user SSH key got corrupted or deleted. It might be scary at first, but the process to recover an opc user SSH key on Oracle Cloud Infrastructure is easy. So if you get a "Permission denied (publickey,gssapi-keyex,gssapi-with-mic)" error when trying to connect via SSH, follow this process to recover your key. Summary ( High Level Steps Stop the instance that you can't log in to. Detach the boot volume. Attach the boot volume to a running Linux instance. Run the iSCSI commands to attac...

Running Graphical Applications Securely Oracle Cloud Infrastructure     Some Linux applications and installers require a graphical interface instead of a simple command line. Some reasons for this requirement are the complexity of the installation or application, requirements for data entry, or to provide a better user experience. By default, Oracle Cloud Infrastructure Linux instances are used by entering the command line via an SSH session. To get a graphical application to run, the typical process is to install VNC, open the TCP port in the security list, and start running. When run in this way, however, VNC can present a security problem, particularly when run over a direct connection to the instance via the internet.     Please follow below link . All steps has documented in detail:   https://cloud.oracle.com/iaas/whitepapers/run_graphical_apps_securely_on_oci.pdf     Happy Learning . 

Monitoring a Database with Enterprise Manager Express - OCI In this article we will see how we can enable Enterprise Manager Express tool in OCI . EM express console is not enabled on version 18c, 12c database by default. You can enable it using below method on Oracle Cloud Infrastructure. Steps mentioned for 1- and 2-node RAC DB Systems You must also update the security list and iptables for the DB system  as well. When you enable the console, you'll set the port for the console. The procedure below uses port 5500(default or you can choose different port as well in my case i am choosing 5501), but each additional console enabled on the same DB system will have a different port. To enable the EM Express console for 1 RAC Node To set the required permissions on a 2-node RAC DB system To open ports on the DB system To connect to the EM Express console To enable the EM Express console for 1 RAC Node 1. SSH to the DB system, log in as opc, sudo to the oracle user, and lo...

Database Creation Issue on DBaaS Service in OCI Issue : Invalid Parameter - VCN RESOLVER FOR DNS AND DNS LABEL must be enabled for all subnets used to launch the specified shape. This issue was caused by a configuration of the custom DNS resolver option in Oracle Cloud Infrastructure virtual cloud network (VCN) settings. This post explains the issue and how to resolve it. When customers configure a subnet within a VCN, they can choose Internet and VCN Resolver or Custom Resolver when configuring the DHCP options. The default is Internet and VCN Resolver. If customers want to use their on-premises DNS servers across the FastConnect or IPSec VPN, they can select Custom Resolver. Generally, most enterprise customers put a DNS relay in the VCN within a shared services subnet. Typically the subnets within the VCN reflect this configuration. This works great for the applications. However, the issue starts when customers try to provision an Oracle Database Cloud ...

OCI Database connection from SQL Developer. In last article we have seen how to create database service and how to make connection from VM. If you don't see please refer to below article : https://himanshusinhadba.blogspot.com/2019/02/database-as-service-dbaas-create.html Login to OCI Console. Now DB System is ready.     Click on DB system name :       Now We have public IP, Private IP of DB Instance and DB name . That’s we Need for Client Connection. Connection from SQL Developer is 2 Phase process :   Make SSH connection to Server VM. Make SQL Net connection using SSH connection.   Requirement : Public IP Private IP DB SID Name Let’s GO : 1. Make SSH connection to Server :   Open SQL Developer from client machine.         Click on SSH , Right Click on SSH.             Verify DB Connection now : Right Cl...