ORACLE DATABASE PROBLEM AND SOLUTIONS

Wednesday, May 24, 2023

How to Install podman on RHEL ?

Install podman on RHEL

[root@10.1.1.1 ~]#

[root@10.1.1.1 ~]# yum install podman

Updating Subscription Management repositories.

Unable to read consumer identity

This system is not registered with an entitlement server. You can use subscription-manager to register.

Last metadata expiration check: 0:48:48 ago on Tue 23 May 2023 10:55:23 PM IST.

Dependencies resolved.

==============================================================================================================================

Package Arch Version Repository Size

==============================================================================================================================

Installing:

podman

[root@10.1.1.1 ~]#

[root@10.1.1.1 ~]# podman pull docker.io/publici/httpd

Trying to pull docker.io/publici/httpd:latest...

Getting image source signatures

Copying blob 0af70aecf67e done

Copying blob a3ed95caeb02 done

Copying blob efd26ecc9548 done

Copying blob 70bd0340825a done

Copying blob 302abf37f8d6 done

Copying blob 2f02fbf07b78 done

Copying blob f3dd40690212 done

Copying blob a3ed95caeb02 skipped: already exists

Copying blob 7043ffb37ce5 done

Copying blob 9654cb0d97aa done

Copying blob a3ed95caeb02 skipped: already exists

Writing manifest to image destination

Storing signatures

2cc7fca9b1ef5fc72cb830a3480e07080d63c6a02ce744c628ed69cd40ebb661

[root@10.1.1.1 ~]#

[root@10.1.1.1 ~]# podman ps

CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES

[root@10.1.1.1 ~]#

[root@10.1.1.1 ~]# podman images

REPOSITORY TAG IMAGE ID CREATED SIZE

docker.io/publici/httpd latest 2cc7fca9b1ef 7 years ago 320 MB

[root@10.1.1.1 ~]#

[root@10.1.1.1 ~]# podman run -dt -p 8080:80/tcp docker.io/publici/httpd

d6bf684def18a8b23f8367e9c164bfca7847e4d100a8d4fa7f7b4fd69aa675f3

[root@10.1.1.1 ~]#

[root@10.1.1.1 ~]# podman ps

CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES

d6bf684def18 docker.io/publici/httpd:latest /usr/sbin/apache2... 14 seconds ago Up 14 seconds 0.0.0.0:8080->80/tcp blissful_shaw

[root@10.1.1.1 ~]#

[root@10.1.1.1 ~]# podman logs -l

AH00558: apache2: Could not reliably determine the server's fully qualified domain name, using 10.88.0.2. Set the 'ServerName' directive globally to suppress this message

[root@10.1.1.1 ~]#

[root@10.1.1.1 ~]# podman ps

CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES

d6bf684def18 docker.io/publici/httpd:latest /usr/sbin/apache2... 2 minutes ago Up 2 minutes 0.0.0.0:8080->80/tcp blissful_shaw

[root@10.1.1.1 ~]#

[root@10.1.1.1 ~]# podman stop d6bf684def18

d6bf684def18

[root@10.1.1.1 ~]#

ANURAG PANDEY

I am Anurag Pandey, working as Cloud Database Architect | Migration & Modernization Expert . Database Administration and Implementation. Provide technical guidance and work with global team. Extensive Experience in Database Installation and Configuration, Real Application Cluster (RAC), ASM, Dataguard , Patching, Upgrade, RMAN, Performance Tuning, Backup and Recovery, Azure, Google, AWS Cloud, AWS RDS, MySQL, Database Migration Service(DMS),CloudEndure - MGN, Azure Site Recovery, Azure Migrate, Datapump, terraform automation, Ansible

Tuesday, May 23, 2023

Cockpit – Powerful Tool to Monitor and Administer Linux Server

Cockpit – Powerful Tool to Monitor and Administer Linux Server

check cockpit package status

[root@i10.1.1.1]#

[root@i10.1.1.1]# rpm -qa | grep -i cockpit

[root@i10.1.1.1]#

Install cockpit package

[root@i10.1.1.1]# yum install cockpit

Updating Subscription Management repositories.

Unable to read consumer identity

This system is not registered with an entitlement server. You can use subscription-manager to register.

Last metadata expiration check: 0:01:14 ago on Tue 23 May 2023 10:55:23 PM IST.

Dependencies resolved.

==============================================================================================================================

Package Architecture Version Repository Size

==============================================================================================================================

Installing:

cockpit

check cockpit service status

[root@i10.1.1.1]#

[root@i10.1.1.1]# systemctl status cockpit

● cockpit.service - Cockpit Web Service

Loaded: loaded (/usr/lib/systemd/system/cockpit.service; static; vendor preset: disabled)

Active: inactive (dead)

Docs: man:cockpit-ws(8)

[root@i10.1.1.1]#

[root@i10.1.1.1]# systemctl start cockpit

[root@i10.1.1.1]#

[root@i10.1.1.1]# systemctl status cockpit

● cockpit.service - Cockpit Web Service

Loaded: loaded (/usr/lib/systemd/system/cockpit.service; static; vendor preset: disabled)

Active: active (running) since Tue 2023-05-23 22:57:42 IST; 6s ago

Docs: man:cockpit-ws(8)

Process: 7009 ExecStartPre=/usr/libexec/cockpit-certificate-ensure --for-cockpit-tls (code=exited, status=0/SUCCESS)

Main PID: 7034 (cockpit-tls)

Tasks: 1 (limit: 48777)

Memory: 1.4M

CGroup: /system.slice/cockpit.service

└─7034 /usr/libexec/cockpit-tls

May 23 22:57:41 ip-172-31-19-40.ec2.internal systemd[1]: Starting Cockpit Web Service...

May 23 22:57:42 ip-172-31-19-40.ec2.internal systemd[1]: Started Cockpit Web Service.

[root@i10.1.1.1]#

Cockpit URL : https://10.1.1.1:9090/users

ANURAG PANDEY

How to setup SSH Passwordless Login in Linux ?

Setup SSH Passwordless Login in Linux for oracle user

Source server : 10.1.1.1

Target server : 10.1.1.2

Genrate SSH key pair

[oracle@10.1.1.1]$ ssh-keygen

Generating public/private rsa key pair.

Enter file in which to save the key (/home/oracle/.ssh/id_rsa):

Enter passphrase (empty for no passphrase):

Enter same passphrase again:

Your identification has been saved in /home/oracle/.ssh/id_rsa.

Your public key has been saved in /home/oracle/.ssh/id_rsa.pub.

The key fingerprint is:

SHA256:CQIzV4K1UyZ/7WmRtLTyPb1N3EHRXoZj4W09bbcQtDk oracle@ip-10.1.1.1.ec2.internal

The key's randomart image is:

+---[RSA 3072]----+

| +o=.+ o .o.=o|

| .= B + + .O.*|

| + o o * E.*O|

| o o = + .o+B|

| S = o ..+|

| . . + |

| . .|

| |

+----[SHA256]-----+

[oracle@10.1.1.1]$

Upload SSH Key to target server – 10.1.1.2

ssh-copy-id oracle@10.1.1.2

[oracle@10.1.1.1]$

[oracle@10.1.1.1]$ ssh-copy-id oracle@10.1.1.2

/usr/bin/ssh-copy-id: INFO: Source of key(s) to be installed: "/home/oracle/.ssh/id_rsa.pub"

The authenticity of host '172.31.21.233 (172.31.21.233)' can't be established.

ECDSA key fingerprint is SHA256:0cU9N1c6iec4IMkhQeT8s7FmzF04X0iLy8pytlr1JCk.

Are you sure you want to continue connecting (yes/no/[fingerprint])? yes

/usr/bin/ssh-copy-id: INFO: attempting to log in with the new key(s), to filter out any that are already installed

/usr/bin/ssh-copy-id: INFO: 1 key(s) remain to be installed -- if you are prompted now it is to install the new keys

oracle@172.31.21.233's password:

Number of key(s) added: 1

Now try logging into the machine, with: "ssh 'oracle@10.1.1.2"

and check to make sure that only the key(s) you wanted were added.

[oracle@10.1.1.1]$

Test and validate passwordless login

Option:1

[oracle@10.1.1.1]$

[oracle@10.1.1.1]$ ssh oracle@10.1.1.2

Create an account or view all your systems at https://red.ht/insights-dashboard

Last login: Tue May 23 16:57:35 2023

[oracle@10.1.1.2 ~]$

Option:2

[oracle@10.1.1.1]$ ssh -l oracle 10.1.1.2

Create an account or view all your systems at https://red.ht/insights-dashboard

Last login: Tue May 23 17:06:21 2023 from 10.1.1.1

[oracle@10.1.1.2]$

ANURAG PANDEY

How to Set Timezone Using timedatectl Command in Linux ?

Set Timezone Using timedatectl Command in Linux

Check current time and timezone details :

option:1

[root@0.0.0.0]#

[root@0.0.0.0]# timedatectl status

Local time: Tue 2023-05-23 13:53:08 UTC

Universal time: Tue 2023-05-23 13:53:08 UTC

RTC time: Tue 2023-05-23 13:53:09

Time zone: UTC (UTC, +0000)

System clock synchronized: yes

NTP service: active

RTC in local TZ: no

[root@0.0.0.0]#

Option:2

[root@0.0.0.0]#

[root@0.0.0.0]# timedatectl

Local time: Tue 2023-05-23 13:57:09 UTC

Universal time: Tue 2023-05-23 13:57:09 UTC

RTC time: Tue 2023-05-23 13:57:10

Time zone: UTC (UTC, +0000)

System clock synchronized: yes

NTP service: active

RTC in local TZ: no

[root@0.0.0.0]#

Get Timezone name using timedatectl:

[root@0.0.0.0]#

[root@0.0.0.0]# timedatectl list-timezones | grep -i kolkata

Asia/Kolkata

[root@0.0.0.0]#

Set timezone using timedatectl command :

[root@0.0.0.0]#

[root@0.0.0.0]# timedatectl set-timezone "Asia/Kolkata"

[root@0.0.0.0]#

Validate time and timezone

[root@0.0.0.0]#

[root@0.0.0.0]# timedatectl

Local time: Tue 2023-05-23 19:28:34 IST

Universal time: Tue 2023-05-23 13:58:34 UTC

RTC time: Tue 2023-05-23 13:58:35

Time zone: Asia/Kolkata (IST, +0530)

System clock synchronized: yes

NTP service: active

RTC in local TZ: no

[root@0.0.0.0]#

ANURAG PANDEY