setup password less connectivity between two Linux server using ssh-keygen

setup password less connectivity between two Linux server  

-bash-4.2$

-bash-4.2$ ssh-keygen

Generating public/private rsa key pair.

Enter file in which to save the key (/var/lib/pgsql/.ssh/id_rsa):

Created directory '/var/lib/pgsql/.ssh'.

Enter passphrase (empty for no passphrase):

Enter same passphrase again:

Your identification has been saved in /var/lib/pgsql/.ssh/id_rsa.

Your public key has been saved in /var/lib/pgsql/.ssh/id_rsa.pub.

The key fingerprint is:

SHA256:XHvRME2FNaXO6wAHk1wjPpjdzHwAJX6RY7yrvSfm7/g postgres@ip-172-31-86-192.ec2.internal

The key's randomart image is:

+---[RSA 2048]----+

|          ++O+.==|

|         B X=Bo..|

|        o @.Bo+  |

|       . . *.=   |

|        S o o.o  |

|           +.  . |

|           o. .  |

|          . ++.  |

|           o+BE  |

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

-bash-4.2$

-bash-4.2$

-bash-4.2$

-bash-4.2$

-bash-4.2$

-bash-4.2$ ssh-copy-id postgres@172.31.85.11

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

/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

postgres@172.31.85.11's password:

Number of key(s) added: 1

Now try logging into the machine, with:   "ssh 'postgres@172.31.85.11'"

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

-bash-4.2$

try to test the login :

-bash-4.2$ ssh 172.31.85.11

Last login: Tue Dec 27 10:41:27 2022

       __|  __|_  )

       _|  (     /   Amazon Linux 2 AMI

      ___|\___|___|

https://aws.amazon.com/amazon-linux-2/

-bash-4.2$

-bash-4.2$

PostgreSQL : How to verify archive mode is enabled or not

 How to verify archive mode is enabled or not

Login to PostgreSQL database with super privilege 

postgres=#

postgres=# show archive_mode;

 archive_mode

--------------

 off

(1 row)

postgres=#

How to check terraform version using command line

 

Check terraform version using command line :

PS C:\test_terraform> terraform  version

Terraform v1.2.8

on windows_amd64

+ provider registry.terraform.io/hashicorp/aws v4.22.0

PS C:\test_terraform>

PS C:\test_terraform>

Download Terraform binary software

 

Use below link to download the Terraform 

https://www.terraform.io/downloads

Download Sample database for oracle

 

Here is the link to download sample database for oracle :

https://www.oracle.com/in/database/technologies/appdev/datamodeler-samples.html

https://www.oracle.com/database/technologies/spatial-graph-here-data-downloads.html

User unable to login /connect with database after upgrade AWS RDS to 19c Database : Error - ORA-01017: invalid username/password

 

Users unable to login / connect with database after upgrade AWS RDS to 19c : Error - ORA-01017: invalid username/password

App users were getting below error after upgrade the AWS Oracle RDS database version 12c to 19c .

ORA-01017: invalid username/password;

Solution :

Need to update below parameter in parameter group :

 

sqlnetora.sqlnet.allowed_logon_version_server  => 8

Also check password version : 

SELECT USERNAME,ACCOUNT_STATUS,PASSWORD_VERSIONS FROM DBA_USERS;

RMAN Error : ORA-19809: limit exceeded for recovery files, ORA-19804: cannot reclaim

 
RMAN Error : ORA-19809: limit exceeded for recovery files, ORA-19804: cannot reclaim

channel ORA_DISK_1: backup set complete, elapsed time: 00:00:02

RMAN-00571: ===========================================================

RMAN-00569: =============== ERROR MESSAGE STACK FOLLOWS ===============

RMAN-00571: ===========================================================

RMAN-03009: failure of backup command on ORA_DISK_1 channel at 03/11/2022 09:46:38

ORA-19809: limit exceeded for recovery files

ORA-19804: cannot reclaim 27108864 bytes disk space from 41474836 limit

Possible Solutions :

• Check backup retention in RMAN configuration 
• check FRA size  : DB_RECOVERY_FILE_DEST_SIZE 
• crosscheck backup/archive and delete 

Solution for Git Error : fatal: Not a valid object name: 'master'.

 fatal: Not a valid object name: 'master'. 

We are getting this error due to master branch is not present . 

so we have to create empty master branch :

Solutions:

[root@oracle19c production]# git branch dev

fatal: Not a valid object name: 'master'.

[root@oracle19c production]#

[root@oracle19c production]#

[root@oracle19c production]# git commit --allow-empty -m "anurag"

[master (root-commit) 47e4721] anurag

[root@oracle19c production]#

[root@oracle19c production]# ls -la

total 0

drwxr-xr-x. 1 root root   8 Feb 26 17:45 .

dr-xr-x---. 1 root root 230 Feb 26 17:45 ..

drwxr-xr-x. 1 root root 134 Feb 26 17:48 .git

[root@oracle19c production]#

[root@oracle19c production]#

[root@oracle19c production]# git branch dev

[root@oracle19c production]#

[root@oracle19c production]#

How to Create / Install repo on Solaris 11.4 ?

 Create / Install repo on Solaris 11.4

root@solaris11:/package_sol#

root@solaris11:/package_sol# ./install-repo.ksh -d repo/

Using sol-11_4-repo download.

Uncompressing sol-11_4-repo_1of5.zip...done.

Uncompressing sol-11_4-repo_2of5.zip...

done.

Uncompressing sol-11_4-repo_3of5.zip...done.

Uncompressing sol-11_4-repo_4of5.zip...

done.

Uncompressing sol-11_4-repo_5of5.zip...done.

Repository can be found in repo/.

root@solaris11:/package_sol#

root@solaris11:/package_sol#

root@solaris11:/package_sol#

root@solaris11:/package_sol# pkg set-publisher -G '*' -M '*' -g /package_sol/repo solaris

root@solaris11:/package_sol#

root@solaris11:/package_sol#

root@solaris11:/package_sol#

root@solaris11:/package_sol#

root@solaris11:/package_sol# pkg info -r solaris-desktop

          Name: group/system/solaris-desktop

       Summary: Oracle Solaris Desktop

   Description: Provides an Oracle Solaris desktop environment

      Category: Meta Packages/Group Packages

         State: Not installed

     Publisher: solaris

       Version: 11.4

        Branch: 11.4.0.0.1.15.0

Packaging Date: Fri Aug 17 00:35:39 2018

          Size: 2.52 kB

          FMRI: pkg://solaris/group/system/solaris-desktop@11.4-11.4.0.0.1.15.0:20180817T003539Z

root@solaris11:/package_sol#

root@solaris11:/package_sol#

root@solaris11:/package_sol# pkg install solaris-desktop

           Packages to install: 357

           Mediators to change:   1

            Services to change:  17

       Create boot environment:  No

Create backup boot environment:  No

DOWNLOAD                                PKGS         FILES    XFER (MB)   SPEED

Completed                            357/357   61930/61930  958.4/958.4      --

PHASE                                          ITEMS

Installing new actions                   76265/76265

Updating package state database                 Done

Updating package cache                           0/0

Updating image state                            Done

Creating fast lookup database                   Done

Updating package cache                           1/1

root@solaris11:/package_sol#

root@solaris11:/package_sol#

root@solaris11:/package_sol#

root@solaris11:/package_sol#

root@solaris11:/package_sol#

root@solaris11:/package_sol# shutdown -i6 -g0 -y

AWS Certified Database Specialty

 

How to empty swap if there is free RAM? : Linux Red-hat OS

Using root user 

 

 free -m

              total        used        free      shared  buff/cache   available

Mem:          15646        3908        1360        3237       10376        8192

Swap:           699         285         414

swapoff -a

swapon -a

 free -g

              total        used        free      shared  buff/cache   available

Mem:             15           4           1           3          10           7

Swap:             0           0           0

Detach Home from Oracle Inventory - 19c oracle database

 

Go to below location :

/u01/app/oracle/product/19.0.0/dbhome/oui/bin

[oracle@ip- bin]$

[oracle@ip- bin]$

[oracle@ip- bin]$ ./runInstaller -silent -detachhome -invPtrLoc /etc/oraInst.loc oracle_home="/u01/app/oracle/product/19.0.0/dbhome" ORACLE_HOME_NAME="OraDB19Home1"

Starting Oracle Universal Installer...

Checking swap space: must be greater than 500 MB.   Actual 699 MB    Passed

The inventory pointer is located at /etc/oraInst.loc

You can find the log of this install session at:

 /u01/app/oraInventory/logs/DetachHome2022-01-03_05-40-07PM.log

'DetachHome' was successful.

[oracle@ip- bin]$

[oracle@ip- bin]$

[oracle@ip- bin]$

[oracle@ip- bin]$

[oracle@ip- bin]$

[oracle@ip- bin]$ pwd

/u01/app/oracle/product/19.0.0/dbhome/oui/bin

[oracle@ip- bin]$