have a problem on the start server some services do not work and I have tried many things to solve I could not get there so I decided to ask the university for help I thank you
If the above solution did not work, Here is another tips:
1. Make sure that you are using compatible and fixed database.
2. Make sure that your server files is connecting properly on your database.
To test all connectivity between your server and your database in a perfect way, you can use Telnet on your Linux server to create TCP connection. Telnet will tell you if the connection of database to your server is working or failing.
How to install Install Telnet?
Some hosting provider are including pre-installed Telnet, But if not, Here it is.
Check if you have telnet installed. You can do it by running this command:
Command: telnet ?
If it gives return message like this:
usage: telnet [-l user] [-a] [-s src_addr] host-name [port]
then you have it ready to use.
But if it gives "Command not found" then, You will be needing to install it.
You can install it by simply running this command on your CentOs:
Command: yum install telnet
To troubleshoot on your database host side, You can try this.
- Log in to the database server
- Run the it "/as sysdba" command to connect to the database
- Run the select INSTANCE_NAME, STATUS from v$instance; command to check the status of database instances.
PS: If you are lazy to learn how to troubleshoot Database problems, Then, I suggest to just use clean database shared here on RZ.