Serba-serbi Operating System

 Umar bin Khattab - Episode 2

Installing pip for Python 3 Ubuntu 18.04 ships with Python 3, as the default Python installation. Complete the following steps to install pip (pip3) for Python 3: Start by updating the package list using the following command: $ sudo apt update Use the following command to install pip for Python 3: $sudo apt install python3-pip The command above will also install all the dependencies required for building Python modules. Once the installation is complete, verify the installation by checking the pip version: $ pip3 --version The version number may vary, but it will look something like this: pip 9.0.1 from /usr/lib/python3/dist-packages (python 3.6) Installing pip for Python 2 Python 2 is not installed by default in Ubuntu 18.04. To install Python 2 and pip for Python 2, complete the following steps: Update the package index by running the following command: $ sudo apt update Install pip for Python 2 with: $ sudo apt install python-pip The command above will install Python2, Pip and all ...

FMW 12.2.1.3.0: "ONS configuration failed" or "oracle.ons.NoServersAvailable: Subscription time out" Solving To implement the workaround in the Configuration Wizard(config.sh) set the following environment variable before launching config.sh. $ export CONFIG_JVM_ARGS=-Doracle.jdbc.fanEnabled=false

To disable the firewall, run the following commands. # service iptables stop # chkconfig iptables off

To remove Oracle JDK, It could be done like this: Remove the link: $ sudo update-alternatives —remove "java" "/usr/lib/jvm/jdk[version]/bin/java"   $ sudo update-alternatives —remove "javac" "/usr/lib/jvm/jdk[version]/bin/javac"   $ sudo update-alternatives —remove "javaws" "/usr/lib/jvm/jdk[version]/bin/javaws" Then, remove the package in the /usr/lib/jvm: $ sudo rm -r /usr/lib/jvm/jdk[version]

After installing the Oracle 12c, I have created the new schema(s). Once I created the schema also installed the Oracle Sql Developer. I created the new connection but I am not able to connect through the Oracle sql developer. I am able to connect through sqlplus. while try to connect through the oracle sql developer am getting the error.  lo exception: The Network Adapter could not establish the connection Solution $ sudo systemctl stop  firewalld

Unicast: Say you have three servers (MS-1,MS-2,MS-3) in a cluster now if they have to communicate with each other they have to ping (i.e. heartbeats ) the cluster master for informing him that he is alive. If MS-1 is the master then MS-2 and MS-3 would send the ping to MS-1 Multicast: Here there is no cluster master each server has to ping each other to inform everyone that I am alive. So MS-1 would send the ping to MS-2 & MS-3 same way MS-2 would send the ping to MS-1 & MS-3 and MS-3 would ping MS-1 & MS-3. Thus if you see in multicast the congestion in sending the pings are more compared to unicast which makes multicast much heavier, thus WLS recommends using Unicast of less congestion in the network.

Windows Subsystem for Linux can use (mount): SD card USB drives CD drives (CDFS) Network drives UNC paths Local storage / drives Drives formatted as FAT, ExFAT or NTFS can be mounted in WSL. For this example, we assume the drive shows in Windows as F:\ If Windows changes the USB drive letter on a subsequent session, you need to repeat this process. The commands are typed into the Windows Subsystem for Linux Terminal. Create a mount location in WSL: $ sudo mkdir /mnt/f Mount the drive in WSL: $ sudo mount -t drvfs f: /mnt/f After this one-time setup, one can create and manipulate files from both Windows and WSL on the same drive. network storage Here we assume: networked storage is already showing in Windows under \\server\share we want to access this network storage from WSL as /mnt/share Create a mount location in WSL: $ sudo mkdir /mnt/share Mount the network share in WSL: $ sudo mount -t drvfs '\\server\share' /mnt/share

Backup / Cloning USB to Image: $ sudo dd if=/dev/sdb1 of=/home/ivanhoe/murrotal-advance.img bs=4M status=progress Restore Image to USB: $ sudo dd if=/home/ivanhoe/murrotal-advance.img of=/dev/sdb1 bs=4M status=progress

Let us see some examples and commands to change a user and group ID in Linux: To assign a new UID to user called foo, enter: # usermod -u 2005 foo To assign a new GID to group called foo, enter: # groupmod -g 3000 foo Verify that you changed UID and GID for given users with the help of ls command: # ls -l

How To Change SYS user password for oracle database instance If you have ever tried to change the SYS of a normal or ASM database instance Password, you would get errors as below : SQL> password Changing password for SYS Old password: New password: Retype new password: ERROR: ORA-00600: internal error code, arguments: [15051], [], [], [], [], [], [], [] SQL> select INSTANCE_NAME from v$instance; INSTANCE_NAME ---------------- +ASM SQL> ALTER USER sys IDENTIFIED BY [new_password] REPLACE [old_password]; ALTER USER sys IDENTIFIED BY [new_password] REPLACE [old_password] * ERROR at line 1: ORA-01109: database not open The following error also might occur: SQL> alter user sys identified by ; alter user sys identified by * ERROR at line 1: ORA-01031: insufficient privileges The reason behind these failures are – The password should be the one provided when the password file was created, also REMOTE_LOGIN_PASSWORDFILE should be se...

OPW-00005: File with same name exists - please delete or rename: Solving oracle@unknown:/u01/oracle/products/12/dbhome_1/dbs$ mv orapworcl orapworcl.bak oracle@unknown:/u01/oracle/products/12/dbhome_1/dbs$ orapwd file=$ORACLE_HOME/dbs/orapworcl password=passwordDB

ORA-12154: TNS:could not resolve the connect identifier specified: Solution Verify a TNSNames.ora file exists on the QuickConnect server By default, the TNSNames.ora file resides in <OracleInstallDirectory>\network\admin If the TNSNames.ora file does not exist, reference the following guide on how to create one: https://oracle-base.com/articles/misc/oracle-network-configuration Set the TNS_Admin environment variable if it is not set:     Navigate to Control Panel > System     Select Advanced System Settings     In the Advanced tab, select Environment Variables     Under System Variables, click New     In the Variable name text box, type TNS_ADMIN     In the Variable value text box, type the location of the TNSNames.ora file     Click OK to add the variable     Restart the server

ERROR ORACLE DB: The version 12.2.0.1.0 of the database that you are using is not a supported version or The specified user may not have sufficient privileges to perform this operation. User should have sysdba or dba privileges. Solution SQL> alter system set db_32k_cache_size = 512M scope=both;

How do I resolve this "ORA-01109: database not open" error? As the error states - the database is not open - it was previously shut down, and someone left it in the middle of the startup process. They may either be intentional, or unintentional (i.e., it was supposed to be open, but failed to do so). Solution Assuming that's nothing wrong with the database itself, you could open it with a simple statement: SQL> ALTER DATABASE OPEN;

BASH - Delete empty lines using sed command under Linux / UNIX: $ sed -i '/^$/d' file

BASH - Convert Date Time: $ date="20181108101344z"; echo -e "date -d \"${date[@]:0:8} ${date[@]:8:2}:${date[@]:10:2}:${date[@]:12:3}+0 hours\" '+%c'" Output: Kam 08 Nov 2018 05:13:44  WIB

BASH - Convert TimeStamp to Date: $ date -d @1560009306 Output: Sab Jun  8 22:55:06 WIB 2019

Install missing ifconfig command on Debian Linux: $ sudo apt-get install net-tools

BASH - Lowercase the word: $ echo "IVANHOE" | tr '[:upper:]' '[:lower:]' Output: ivanhoe