“yum upgrade and yum update will perform the same function that update to the latest current version of package. But the difference is Upgrade will delete obsolete packages, while update will preserve them.Jul 3, 2014”

https://unix.stackexchange.com/questions/55777/in-centos-what-is-the-difference-between-yum-update-and-yum-upgrade

3.3. UPDATING PACKAGES FROM THE COMMAND LINE WITH YUM

https://access.redhat.com/documentation/en-us/red_hat_network_satellite/5.5/html/reference_guide/sect-reference_guide-package_updater-updating_packages_from_the_command_line_with_yum

yum install package_name
yum update package_name
yum check-update
yum remove package_name
yum provides package_name
yum search keyword
yum localinstall absolute path to filename

Reference: the above link

Check if your yum server is working or not

yum repolist
yum install tree

yum repolist enabled
yum repolist all

Let FTP work through Firewall

firewall-cmd –add-service=vsftpd –perm
firewall-cmd –add-service=ftp –perm
systemctl reload firewalld
systemctl start firewalld
systemctl enable firewalld
vi /etc/yum.repos.d/local.repo

AutoFS and Mounting in Linux/Redhat/CentOS

echo “AutoFS – Automatic FS system Mounting – Dec 26th, 2017 by Sayed”

check if Autofs installed or not
yum list installed | grep autofs

I just installed; hence it is there
you can install with yum -y install autofs

yum -y install autofs

then you can enable autofs
systemctl status autofs
systemctl start autofs
systemctl enable autofs

enable – will start this service at reboot/system start

AutoFS in general does not use /etc/fstab
AutoFS uses /etc/mtab file
Also, AutoFS has some files under /etc and starting with auto. You can also define which file will contain the mounting mapping. the file that will act like /etc/fstab for autofs

AutoFS has direct mapping and indirect mapping
let’s see some files under /etc for autofs

ls /etc/auto*

The files

/etc/auto.direct /etc/autofs.conf /etc/autofs_ldap_auth.conf /etc/auto.master /etc/auto.misc /etc/auto.net /etc/auto.smb /etc/auto.master.d:

I saw to use /etc/auto.master for configuring which file will do the mapping for direct mounting.
I saw to use /etc/auto.misc for configuring which file will do the mapping for indirect mounting for AutoFS.

One more config file is under: /etc/sysconfig/autofs

cat /etc/sysconfig/autofs

the content
#

Init system options

#

If the kernel supports using the autofs miscellanous device

and you wish to use it you must set this configuration option

to “yes” otherwise it will not be used.

#
USE_MISC_DEVICE=”yes”
#

Use OPTIONS to add automount(8) command line options that

will be used when the daemon is started.

#

OPTIONS=””

#

For mounting NFS i.e. remote/network file-systems/folders – we can use the regular mounting i.e. /etc/fstab and mount command. However, that is kinda manual. We can mount NFS using AutoFS that will be automatic mount

We use AutoFS for LDAP clients to auto mount Users’ home directories. We just configure, then the mounting happens automatically. You remember that getent passwd user-name mounted the remote users’ home directory into local system. we used /etc/auto.master to tell that auto.guests will have the mounting configurations. then on /etc/auto.guests file – we configured that users’ home directories will be mounted on /home/guests. you can check our notes on LDAP client configuration

cat /etc/auto.master
vim /etc/auto.master

we added the following line on /etc/auto.master
/etc/auto.guests /etc/auto.direct

it just tells that AutoFS will consult /etc/auto.guests file for direct mapping

vim /etc/auto.guests
we added the following line on /etc/auto.guests
/home/guests 192.168.1.15:/nfsrh

it just tells remote /nfsrh will be automatically mounted to /home/guests
you can try to restart autofs

systemctl restart autofs

Indirect Map
indirectly mounted points are only visible when accessed
automatically mounts shares under one common parent directory
each indirect map put only one entry in the mtab file
local and indirect maps cannot exist in the same parent directory
for indirect mapping – you use /etc/auto.misc file From: http://sitestree.com/?p=12070
Categories:DevOps, RHCSA
Tags:
Post Data:2017-12-26 15:27:27

•T/F: Microsoft Windows is a System Software

•T/F: Database Management Systems are System Software

•T/F: Device Drivers are System Software

•Microsoft Word is an Application Software

•True or False: Operating system provides a kernel and Shell/Interface software (among other things)

•T/F: Cars do not have any Microprocessor and Cars cannot have any Operating System

•What do you mean by an Operating System (OS)

•Why do we need an Operating System

•What are the functionalities that an OS provides.

•True or False: System Software and Application software are the same.

•T/F: A Car can have OS

•What do you mean by Resource Management in OS

•What are four primary areas an operating system Operates

•What are some security enforcement features of an OS

•What do you mean by Hardware Abstraction?

•T/F: Providing Frameworks for developers to develop software without dealing with the details of hardware

•

•What are some components of an Operating System

•Service vs System Libraries

•System Software vs Application Software

•System Software vs Utility Software vs Application Software

•Types of OS interface Available?

•Is Linux Shell GUI Based?

Kill a Process

•kill PID

•kill -SIGNAL PID

•Kill –s 9 pid

•Kill -9 pid

•kill -15 PID

•

Important Notes

•System Processes

•usually run

•in the background

•Use & to start

•a process to the background

•Use fg

•to bring to foreground

•Ctrl+z takes to background

Stop-Process -Name “notepad”

Stop-Process -Id 3952 -Confirm –PassThru

calc $p = Get-Process -Name “calc”

Stop-Process -InputObject $p

Get-Process | Where-Object {$_.HasExited}

Get-Process -Name “lsass” | Stop-Process

Get-Process

Get-Process winword, explorer | Format-List *

Get-Process | Where-Object {$_.WorkingSet -gt 20000000}

$A = Get-Process

$A | Get-Process | Format-Table -View priority

Get-Process pwsh -FileVersionInfo (did not work)

Get-Process SQL* -Module

Ref: Internet/Google – MS Sites

ps x

ps -e

ps aux

ps –u username