[root@testsvr01 ~]# useradd -s /sbin/nologin -p password user
[root@testsvr01 ~]# vi /etc/ssh/sshd_config
#Subsystem sftp /usr/libexec/openssh/sftp-server
Subsystem sftp internal-sftp
Match Group user
ForceCommand internal-sftp
ChrootDirectory /home/user
X11Forwarding no
AllowTcpForwarding no
[root@testsvr01~]# lsblk
NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT
sda 8:0 0 100G 0 disk
sdb 8:16 0 500G 0 disk
sdc 8:32 0 500G 0 disk
└─vg_pgdata-lv_pgdata 253:2 0 500G 0 lvm /pgdata
sr0 11:0 1 1024M 0 rom
vda 252:0 0 100G 0 disk
├─vda1 252:1 0 500M 0 part /boot
└─vda2 252:2 0 99.5G 0 part
[root@testsvr01~]# lsblk
NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT
sda 8:0 0 60G 0 disk
├─sda1 8:1 0 1G 0 part /boot
└─sda2 8:2 0 59G 0 part
├─rhel-root 253:0 0 35.6G 0 lvm /
├─rhel-swap 253:1 0 6G 0 lvm [SWAP]
└─rhel-home 253:2 0 17.4G 0 lvm /home
sdb 8:16 0 250G 0 disk
sdc 8:32 0 250G 0 disk
See the below Query to find Unused index in PostgreSQL
[root@testsvr01~]# useradd sysadmin -G wheel
[root@testsvr01~]# passwd sysadmin
Changing password for user sysadmin.
New password:
Retype new password:
passwd: all authentication tokens updated successfully.
[root@testsvr01~]#
MBR Backup
[root@testsvr01~]# dd if=/dev/sda1 of=/opt/mbr_backup bs=512 count=1
0+1 records in
0+1 records out
115 bytes (115 B) copied, 0.0001912 s, 601 kB/s
[root@testsvr01~]#
[root@testsvr01~]# rpm -q kernel
kernel-3.10.0-1160.15.2.el7.x86_64
kernel-3.10.0-1160.21.1.el7.x86_64
kernel-3.10.0-1160.24.1.el7.x86_64
kernel-3.10.0-1160.36.2.el7.x86_64
kernel-3.10.0-1160.71.1.el7.x86_64
[root@ehapp01 ~]# package-cleanup --oldkernels --count=1
Loaded plugins: fastestmirror, langpacks
--> Running transaction check
---> Package kernel.x86_64 0:3.10.0-1160.15.2.el7 will be erased
---> Package kernel.x86_64 0:3.10.0-1160.21.1.el7 will be erased
[root@testsvr01~]# df -Th | grep "^/dev"
/dev/mapper/rhel-root xfs 50G 8.8G 42G 18% /
/dev/vda1 xfs 497M 199M 299M 40% /boot
/dev/mapper/rhel-home xfs 46G 8.9G 37G 20% /home
[root@testsvr01~]#
[root@testsvr01~]# yum install yum-utils
[root@testdbsvr01~]# dnf install -y https://download.postgresql.org/pub/repos/yum/reporpms/EL-8-x86_64/pgdg-redhat-repo-latest.noarch.rpm
[root@testdbsvr01~]# dnf -qy module disable postgresql
[root@testdbsvr01~]# dnf install -y postgresql12-server
[root@testdbsvr01~]# dnf install -y postgresql12-contrib
[root@testdbsvr01~]# /usr/pgsql-12/bin/postgresql-12-setup initdb
Initializing database ... OK
