SSH service runs on 22 port number. You can change this port number for security. If you use Oracle Linux 7, Centos 7 or Red Hat Linux 7 versions, you can change port number with below operations. If selinux is enabled, you have to add new port number to selinux configuration because of the fact that selinux allows only 22 port number for ssh connections.
Step 1 : Change Port Number
[root #] vi /etc/ssh/sshd_config
Save and Exit
Step 2 : Change Selinux Configuration
[root #] semanage port -a -t ssh_port_t -p tcp 2290
[root #] semanage port -l | grep ssh
Step 3 : Restart SSHD Service to Activate New Confiuration
Logical Volume Manager is a disk partitioning solution on linux systems. This architecture provides advantages. You can extend disk size easyly with lvm without losing exist data. But, If you use fdisk that is classical method for partition, you can not resize this partitions without losing data.
You can follow below steps to configure lvm.
LVM Creation Steps
1- Disk partition “cfdisk”
2- Create physical volume “pvcreate”
3- Create virtual group “vgcreate”
4- Create logical volume “lvcreate”
5- Format logical volume “mkfs.ext4″
6- Add Fstab “vi /etc/fstab”
If you mount disk with wrong uuid or wrong text in fstab file, you get an error when system restart. Your system can not open. If you want to change fstab, you can not change this file because of read only. You can change this status with “mount -o remount,rw /” command. This command provides that system takes maintenance mode. /etc/ directory’s below files will be writable.
If you want to change Oracle Enterprise Manager port number, you can use “emca -reconfig ports -DBCONTROL_HTTP_PORT ” command, this is simple. You can use to take security measure for Oracle EM. I will give 1820 as port for Oracle EM as example.
Oracle Wallet Manager is a password protected stand-alone Java application tool used to maintain security credentials and store SSL related information such as authentication and signing credentials, private keys, certificates, and trusted certificates.
1- Create Wallet Directory
[oracle@testdb ~] cd $ORACLE_HOME
[oracle@testdb db_home] mkdir -p ORA_WALLETS
2- Write Wallet Location Information in sqlnet.ora File
[oracle@testdb ~] cd $ORACLE_HOME/network/admin
[oracle@testdb db_home] vi sqlnet.ora
You can move datafiles to different directory. You have to make offline tablespace or take mount mode database to change datafiles location. System, temporary and rollback tablespace can move only when database is mount mode.
Show Tablespaces And Datafiles With Locations
SQL> select tablespace_name, file_name from dba_data_files;
Change Location Of Normal Datafile
SQL> alter tablespace TS_TEST offline;
[oracle@testdb oradata] mv /oradata/ts_test01.dbf to /oradata2/
SQL> alter tablespace TS_TEST rename datafile ‘/oradata/ts_test01.dbf’ to ‘/oradata2/ts_test01.dbf';
SQL> alter tablespace online;