step by step configure sftp server in Linux

 [root@sftp ~]# groupadd  sftp_users

[root@sftp ~]# useradd  -G sftp_users -s /sbin/nologin sftp_user
[root@sftp ~]#
[root@sftp ~]# passwd sftp_user
Changing password for user sftp_user.
New password:
Retype new password:
passwd: all authentication tokens updated successfully.
[root@sftp ~]#
[root@sftp ~]#

[root@sftp ~]# usermod -G sftp_users -s /sbin/nologin sftp_user
[root@sftp ~]# vim /etc/ssh/sshd_config

#comment out the below line and add a line like below
#Subsystem sftp /usr/libexec/openssh/sftp-server
Subsystem sftp internal-sftp

# add Below lines at the end of file
Match Group sftp_users
X11Forwarding no
AllowTcpForwarding no
ChrootDirectory %h
ForceCommand internal-sftp


ChrootDirectory %h – This is the path(default user’s home directory) that will be used for chroot after the user is authenticated. So, for sftp_user, this will be /home/sftp_user.


[root@sftp ~]# systemctl restart sshd.service

[root@sftp ~]# chmod 755 /home/sftp_user/
[root@sftp ~]# chmod 755 /home/sftp_user
[root@sftp ~]# chown root /home/sftp_user
[root@sftp ~]# chgrp -R sftp_users /home/sftp_user

[root@sftp ~]# mkdir /home/sftp_user/upload
[root@sftp ~]# chown sftp_user. /home/sftp_user/upload/
[root@sftp ~]#

[root@sftp ~]# setsebool -P ssh_chroot_full_access on
Boolean ssh_chroot_full_access is not defined
[root@sftp ~]#
[root@sftp ~]#
[root@sftp ~]#
[root@sftp ~]# ssh sftp_user@10.88.13.111
sftp_user@10.88.13.111's password:
This service allows sftp connections only.
Connection to 10.88.13.111 closed.

[root@sftp ~]# sftp sftp_user@10.88.13.111
sftp_user@10.88.13.111's password:
Connected to 10.88.13.111.
sftp> pwd
Remote working directory: /
sftp>

step by step Oracle 12c Data Guard Failover

 Step:1 In standby database check the database role and open_mode

SQL> SELECT OPEN_MODE,PROTECTION_MODE,DATABASE_ROLE FROM V$DATABASE;

OPEN_MODE         PROTECTION_MODE      DATABASE_ROLE
-------------------- -------------------- ----------------
READ ONLY WITH APPLY MAXIMUM PERFORMANCE  PHYSICAL STANDBY

  Step:2 Check archive log gap sequence

 SQL> SELECT THREAD#, LOW_SEQUENCE#, HIGH_SEQUENCE# FROM V$ARCHIVE_GAP;

no rows selected

 Step:3 Cancel MRP process in standby database

SQL> ALTER DATABASE RECOVER MANAGED STANDBY DATABASE CANCEL;

Database altered. 

 Step:4 Bring up standby database as primary 

SQL> alter database recover managed standby database finish;

Database altered.

SQL> alter database activate standby database;

Database altered.

Managed recovery process has been stopped between primary and standby database and standby becomes primary database.

Step:5 Shutdown and startup database and verify database name its open mode and its role.

SQL> shutdown immediate
ORA-01109: database not open


Database dismounted.
ORACLE instance shut down.

SQL> startup
ORA-32004: obsolete or deprecated parameter(s) specified for RDBMS instance
ORACLE instance started.

Total System Global Area 1.6106E+11 bytes
Fixed Size            7653336 bytes
Variable Size         8.1604E+10 bytes
Database Buffers     7.8920E+10 bytes
Redo Buffers          529215488 bytes
Database mounted.
Database opened.
SQL> select open_mode,database_role from v$database;

OPEN_MODE         DATABASE_ROLE
-------------------- ----------------
READ WRITE         PRIMARY

step by step enable archivelog and flashback in Oracle 19c RAC Database

 

Step:-1 Before Changing the archivelog mode  and Flashback Database check the status. 

SQL> select log_mode,flashback_on from gv$database;

LOG_MODE     FLASHBACK_ON

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

NOARCHIVELOG NO

NOARCHIVELOG NO

Step:-2 Stop the rac database service.

[oracle@bamisdbrac02 ~]$ srvctl status database -d misdbrac

Instance misdbrac1 is running on node bamisdbrac01

Instance misdbrac2 is running on node bamisdbrac02

[oracle@bamisdbrac02 ~]$ 

[oracle@bamisdbrac02 ~]$ srvctl stop database -d misdbrac

[oracle@bamisdbrac02 ~]$

Step:-3 Start the rac database in mount state.

[oracle@bamisdbrac02 ~]$ sqlplus

SQL*Plus: Release 19.0.0.0.0 - Production on Sun Nov 14 19:02:36 2021

Version 19.12.0.0.0

Copyright (c) 1982, 2021, Oracle.  All rights reserved.

Enter user-name: /as sysdba

Connected to an idle instance.

SQL> startup mount

ORACLE instance started.

Total System Global Area 6.4425E+10 bytes

Fixed Size    37476752 bytes

Variable Size 1.0872E+10 bytes

Database Buffers 5.3419E+10 bytes

Redo Buffers    96739328 bytes

Database mounted.

SQL> 

[oracle@bamisdbrac01 ~]$ sqlplus

SQL*Plus: Release 19.0.0.0.0 - Production on Sun Nov 14 19:02:04 2021

Version 19.12.0.0.0

Copyright (c) 1982, 2021, Oracle.  All rights reserved.

Enter user-name: /as sysdba

Connected to an idle instance.

SQL> startup mount

ORACLE instance started.

Total System Global Area 6.4425E+10 bytes

Fixed Size    37476752 bytes

Variable Size 1.0335E+10 bytes

Database Buffers 5.3956E+10 bytes

Redo Buffers    96739328 bytes

Database mounted.

SQL> 

Step:-4 Enable archive log mode and Flashback database

[oracle@bamisdbrac02 ~]$ srvctl status database -d misdbrac

Instance misdbrac1 is running on node bamisdbrac01

Instance misdbrac2 is running on node bamisdbrac02

[oracle@bamisdbrac02 ~]$ 

SQL> select FLASHBACK_ON from v$database;

FLASHBACK_ON

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

NO

SQL> archive log list

Database log mode        No Archive Mode

Automatic archival        Disabled

Archive destination        /u01/app/oracle/product/19.3/db_1/dbs/arch

Oldest online log sequence     1772

Current log sequence        1773

SQL> select log_mode,flashback_on from gv$database;

LOG_MODE     FLASHBACK_ON

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

NOARCHIVELOG NO

NOARCHIVELOG NO

SQL> 

alter system set log_archive_dest_1='LOCATION=+FRA/' scope=both sid='*';

alter database archivelog;

alter system set db_recovery_file_dest_size=500G scope=both sid='*';

alter system set db_recovery_file_dest='+FRA' scope=both sid='*';

alter database flashback on;

Step:-5 Stop the RAC database service

[oracle@bamisdbrac02 ~]$ srvctl stop database -d misdbrac

Step:-6 Restart the RAC database

[oracle@bamisdbrac02 ~]$ srvctl start database -d misdbrac

[oracle@bamisdbrac02 ~]$ srvctl status database -d misdbrac

Instance misdbrac1 is running on node bamisdbrac01

Instance misdbrac2 is running on node bamisdbrac02

[oracle@bamisdbrac02 ~]$ 

Step:-7 Check Archivelog and flashback Status 

SQL> select log_mode,flashback_on from gv$database;

LOG_MODE     FLASHBACK_ON

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

ARCHIVELOG   YES

ARCHIVELOG   YES

SQL> 

[oracle@bamisdbrac02 ~]$ sqlplus

SQL*Plus: Release 19.0.0.0.0 - Production on Sun Nov 14 19:11:38 2021

Version 19.12.0.0.0

Copyright (c) 1982, 2021, Oracle.  All rights reserved.

Enter user-name: /as sysdba

Connected to:

Oracle Database 19c Enterprise Edition Release 19.0.0.0.0 - Production

Version 19.12.0.0.0

SQL> select log_mode,flashback_on from gv$database;

LOG_MODE     FLASHBACK_ON

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

ARCHIVELOG   YES

ARCHIVELOG   YES

SQL>