dba

---setup new instance named (gescom)
$ cd $ORACLE_HOME/dbs
$ cp init.ora initgescom.ora
$ gedit initgescom.ora (modifier 3Lih - https://pastebin.com/U14eyGiC)
$ mkdir -p /u01/app/ora11g/admin/gescom/adump

---launch
$ export ORACLE_SID=gescom
$ sqlplus / as sysdba
SQL> startup nomount