How to check Operating Systems Version is 64-bit or 32-Bit

Hello Friends,

In this post, you can see how we will check the operating system is 32 bit or 64 bit. Normally when we download any software on Unix platform they have dependency regarding the operating system version. So after following my this post you can easily get the information about the operating system version information.
When you work on Unix operating system then you must know the version of operating system. Because without getting exact version of OS, you can not install the packages on the Linux system.

Here, I mentioned the command and their output using these commands you can easily found the version of operating system. It is 32 bit or 64 bit.

Linux Operating System:

#uname –a
Linux vibhor 3.10.0-229.el7.x86_64 #1 SMP Fri Mar 6 11:36:42 UTC 2015 x86_64 x86_64 x86_64 GNU/Linux

#uname  -m
x86_64

If the output has "x86_64",the environment is 64 bit.

Solaris Operating System:

#isainfo options

-v         Prints detailed information about the other options
-b         Prints the number of bits in the address space of the native instruction set.
-n         Prints the name of the native instruction set used by portable applications supported by the current version of the OS.
-k         Prints the name of the instruction set or sets that are used by the OS kernel components such as device drivers and STREAMS modules.

[vibhor]# isainfo -v

64-bit sparcv9 applications
        ima fmaf vis2 vis popc
32-bit sparc applications
        ima fmaf vis2 vis popc v8plus div32 mul32

[vibhor]# isainfo -b
64

[vibhor]#isainfo
sparcv9 sparc

The output for the above command should be sparcv9 sparc for a 64-bit operating System.

AIX Operating System:

vibhor:/> getconf -a | grep KERN
KERNEL_BITMODE:                         64

vibhor:/> bootinfo -y
64

The output of the above command should be 64 for a 64-bit hardware. The command must be executed as root.

Note: on AIX, the -y option will specify if the hardware is 32- or 64-bit mode while bootinfo -k will specify if the kernel is 32- or 64-bit (this command must be run as root).

HP-UX Operating system:
         
 hpx:/> getconf KERNEL_BITS
 64
         
The output of the above command should be 64 for a 64-bit operating system.

SQL command for MySQL database on Linux operating system

In this post, i will explain you how we will create, import, export & backup of MySQL database.

Please find the below points which is very useful to database admin on Linux operating system.

How to create new database:

CREATE DATABASE <DATABASENAME>;

e.g. CREATE DATABASE VIBHOR;

In this example I have created the "vibhor" named database, you can replace database name according to your choice.

How to create mater user with all level access to all available databases:

GRANT ALL ON *.* TO <USERNAME> IDENTIFIED BY '<PASSWORD>';

e.g. GRANT ALL ON *.* TO TESTDBUSER IDENTIFIED BY 'TESTDBUSER';

In this example I used "testdbuser" MySQL user on the server. 

How to take backup (dump) of a database:

For this command you need not to login into the database. Once you login on the database please run the below command to take a dump of server.

mysqldump --lock-all-tables -u <USERNAME> -p -h <DATABASESERVERNAME/IP ADDRESS> <DATABASENAME> > <NEWDUMPFILENAME>.sql

e.g. mysqldump --lock-all-tables -u ABC -p -h MACHINE1 VIBHOR > VIBHOR_16022017.sql

After this command you have to provide DB password only and dump will be done in the folder in which u are working currently.

How to take backup (dump) of a table's:

For this command you need not to login into the database.

mysqldump -u <USERNAME> -p <DATABASENAME> <TABLENAME> > <NEWDUMPFILENAME>.sql

e.g. mysqldump -u testdbuser -p testdb test_book > test.sql

After this command you have to provide DB password only and dump will be done in the folder in which u are working currently. for dumping multiple table use space between the table names.

How to run a database dump to another machine:

Go to the folder in which sql dump file is placed and then connect with your Database in which you want to run dump and then run below command.

source <FILENAME>.sql;

e.g source VIBHOR_16022017.sql;

How to take dump only triggers and procedure from database:

mysqldump --routines --no-create-info --no-data --no-create-db --skip-opt -u <USERNAME> -p <DATABASENAME> > <NEWDUMPFILENAME>.sql

e.g. mysqldump --routines --no-create-info --no-data --no-create-db --skip-opt -u TESTDBSUER -p VIBHOR > VIBHOR_16022017.sql

After this command you have to provide DB password only and dump will be done in the folder in which u are working currently.

How to show procedure/function code:

SHOW CREATE PROCEDURE <STORED PROCEDURE/FUNCTION NAME>\G

e.g. SHOW CREATE PROCEDURE FLIGHT_INVOICETOSAP\G;

How to increase filed width of a table attribute:

ALTER TABLE <TABLENAME> CHANGE <EXISTING_FIELD_NAME> <NEW_FIELD_NAME> <DATATYPE>(<NEW_FIELD_WIDTH>);

e.g. ALTER TABLE TRILOK CHANGE PASSENGER_NO PASSENGER_NUMBER VARCHAR(30);

field name and data type change is not recommended.

How to display all existing databases:

SHOW DATABASES;

Using this command you can show all the created database list on the Linux server.

How to display all existing tables:

SHOW TABLES; 

SHOW TABLES LIKE '<CHARACTERS>%';

Using this command you can check all the tables which is created on the database. 

How to recover a MySQL root password:

This is one of the best way to recover the MySQL root password if you forget. I always used below method to reset the root password.

• Stop the MySQL server process.

# /etc/init.d/mysql stop

• Start again with no grant tables.

# mysqld_safe --skip-grant-tables &

• Login to MySQL as root. Set new password.

# mysql -u root

mysql> use mysql;

mysql> update user set password=PASSWORD("newrootpassword") where User='root';

mysql> flush privileges;

mysql> quit

• Exit MySQL and restart MySQL server.

# /etc/init.d/mysql stop

# /etc/init.d/mysql start

• Set a root password if there is on root password.

# mysqladmin -u root password newpassword

• Update a root password.

# mysqladmin -u root -p oldpassword newpassword

How to grant privileges to a user:

If we need to provide the privileges to user we will use below two method. I will describe the step by step method for this one.

METHOD 1

Allow the user "bob" to connect to the server from localhost using the password "passwd". Login as root. Switch to the MySQL db. Give privs. Update privs.

# mysql -u root -p

mysql> use mysql;

mysql> grant usage on *.* to bob@localhost identified by 'passwd';

mysql> flush privileges;

Give user privileges for a db. Login as root. Switch to the MySQL db. Grant privs. Update privs.

# mysql -u root -p

mysql> use mysql;

mysql>INSERT INTO user (Host,Db,User,Select_priv,Insert_priv,Update_priv,Delete_priv,Create_priv,Drop_priv) VALUES ('%','databasename','username','Y','Y','Y','Y','Y','N');

mysql> flush privileges;

METHOD 2

mysql> grant all privileges on databasename.* to username@localhost;

mysql> flush privileges;

To update info already in a table.

Load a CSV file into a table:

mysql> LOAD DATA INFILE '/tmp/filename.csv' replace INTO TABLE [table name] FIELDS TERMINATED BY ',' LINES TERMINATED BY '\n' (field1,field2,field3);

Dump all databases for backup:

Backup file is SQL commands to recreate all databases.

# [mysql dir]/bin/mysqldump -u root -ppassword --opt >/tmp/alldatabases.sql

Dump one database for backup.

# [mysql dir]/bin/mysqldump -u username -p password --databases databasename >/tmp/databasename.sql

Dump a table from a database.

# [mysql dir]/bin/mysqldump -c -u username -p password databasename tablename > /tmp/databasename.tablename.sql

Restore database (or database table) from backup.

# [mysql dir]/bin/mysql -u username -p password databasename < /tmp/databasename.sql

Create Table Example 1.

Using above method we can take database back very fast. I hope through this post you can easily able to create MySQL database, MySQL dump, table creation etc work.

How to boot AIX to Single User Mode in order to perform maintenance

In this post, I will explain to you, how do we boot AIX server to single user mode in order to perform maintenance. AIX is IPM operating system which is widely used today.

In AIX operating system we do not need to use single user mode very much, because many problems or issues require having the root file systems unmounted for repairs. 

In my post you can found the list of some issues when it's good to use single-user.

• System boot hangs due to NFS configuration issues
• Debug problems with entries in /etc/inittab
• If you want to work on the system without users login to attempt.
• If you want to work without applications starting up

Normally when we repair any file system if it is get crashed then we use "fsck" utility and their command but for this repair process the good condition is you need to unmount /tmp & /var file system.

If the system boots fine from the root volume group, then booting into single-user to repair or perform work has advantages. These advantages of this as listed below.

• Its boots faster than Maintenance Mode.
• It allows you to run all commands you would normally have access to in multi user.
• Unlike maintenance mode, there is no possibility that hdisks will be renamed.

Procedure to boot AIX operating system to Single User mode: 

I will explain you two way to boot the system in single user mode which is describe below.

Standalone System (no HMC):

• First boot system with no media in the CD/DVD drive on AIX operating system.
• Wait until you see the options of choosing another boot list, and hear beeps on the console
• Press 6 to start diagnostics

System using an HMC:

• Select the LPAR in the HMC GUI
• Select Operations -> Activate
• In the Activate window, click the button that says "Advanced"
• Change "Boot mode" to "Diagnostic with stored boot list"
• Click "OK" to save that change, then "OK" again to activate.

After above steps you will get the below screen on the AIX operating system monitor. If these below message you get that's means your operating system boot process is already start.

IBM IBM IBM IBM IBM IBM IBM IBM IBM IBM IBM IBM IBM IBM IBM IBM IBM IBM IBM

IBM IBM IBM IBM IBM IBM IBM IBM IBM IBM IBM IBM IBM IBM IBM IBM IBM IBM IBM

1 = SMS Menu 5 = Default Boot List

8 = Open Firmware Prompt 6 = Stored Boot List

You will see the normal AIX boot header, since you are booting from your system hard disk:

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

                                Welcome to AIX.

                       boot image timestamp: 11:55 02/15

                 The current time and date: 15:35:02 02/15/2017

               number of processors: 2    size of memory: 4096MB

          boot device: /vdevice/v-scsi@70000007/disk@2300000000000000

                     kernel size: 15034876; 64 bit kernel

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

Now you will get the diagnostic license information page and their message on the screen which are describe as below. Several keys are used to control the diagnostics:

• The Enter key continues the procedure or performs an action.
• The Backspace key allows keying errors to be corrected.
• The cursor keys are used to select an option.

Now, please press Enter. The next screen will show you Diagnostic Functions you can perform. On newer versions of firmware you will see Option 5 to start Single User Mode.

On older firmware you will have to go to, 3. Task selection and scroll way down and select 'Start Shell' or 'Single User Mode'

Function Selection:

1. Diagnostic Routines: This selection will test the machine hardware. Wrap plugs and other advanced functions will not be used.

2. Advanced Diagnostic Routines: This selection will test the machine hardware. Wrap plugs and other advanced functions will be used.

3. Task Selection(Diagnostics, Advanced Diagnostics, Service Aids, etc.): This selection will list the tasks supported by these procedures. Once a task is selected, a resource menu may be presented showing all resources supported by the task.

4. Resource Selection: This selection will list the resources in the system that are supported by the diagnostic programs. Once a resource is selected, a task menu will be presented showing all tasks that can be run on the resource(s).

5. Single User Mode: The system will enter single-user mode for software maintenance.

To make a selection, type the number and press Enter [1]: 5

Once you select the 5, you can find the below message on screen.

The system will now continue the boot process.  Please wait...

Saving Base Customize Data to boot disk

Starting the sync daemon

Starting the error daemon

System initialization completed.

It is asking for password , you may enter the password and login on single user mode, after login please check the mounted file system using "df" command.

If you want to exit single user mode and boot into multi user mode then you need to run the 

To exit single-user mode and boot into multiuser in RunLevel 2 use:

aix:/>telinit 2

Once you will press this command you can logout from single user mode to multi user mode. I hope you like my post and all the information which i have mention it. 

Step by Step NFS Server and Client Configuration in HP-UX

In this post, I will explain step by step method of NFS server and client configuration on HP-UX operating system. Network File System is a distriubted file system which allows a client computer to access a file system that shared on another computer’s or server's.

NFS server is configured on the server locally on attached physically disk. On my HP-UX server i will configured the NFS server and for client you can use same HP-UX operating machine or other linux machine.

We can used the below NFS server IP and client IP on my own HP-UX machine and Linux machine.

NFS Server : 10.135.0.27 and share folder /backup

NFS Client : 10.135.0.2 and mount point /home/backup

Steps involved to configure the NFS Server:

1. First we will make sure both NFS server(10.135.0.27) and client(10.135.0.2) are accessible. After that we will make an entry in /etc/hosts or Configure it in DNS to resolve the IP if you use server name instead of IP address. But in our case we will use IP address instead of name.

hpx:/>vi /etc/hosts

10.135.0.27 hpxnfsserver

10.135.0.2 hpxnfsclient

The /etc/hosts entry would we same on both server and client machine so it can be accessible to each other.

2. In second step we will identify the folder to be export from server to the client. On my HP-UX server machine, I am going to export the folder /backup.

3. Now we will change the shared folder permission, normally we don't provide the read/write access to shared folder but in my case for testing purpose i will provide the (777) permission so that NFS client user can read/write the data on shared folder.

hpx:/>#chmod 777 /backup

4. In this step we change the NFS_SERVER=1 to enable your server to act as a NFS Server in the configuration file /etc/rc.config.d/nfsconf

hpx:/>vi /etc/rc.config.d/nfsconf

Change the NFS_SERVER parameter as follow.

NFS_SERVER=1

PCNFS_SERVER=0

START_NFSLOGD=0

START_MOUNTD=1

MOUNTD_OPTIONS=""

Save and exit the file.

5. In final step we will add an entry of our shared folder in the export file /etc/dfs/dfstab with proper permission.

#vi /etc/dfs/dfstab

/usr/sbin/share -F nfs -o rw -d “Test directory” /backup

Save and exit the file.

If you see the above line "/backup is shared folder and we will provide the "rw" read/write access to this folder.

6. Now please restart the nfs service on NFS server and make it permanent so after reboot of HP-UX server the shared folder is not umount.

hpx:/>/sbin/init.d/nfs.server stop

hpx:/>/sbin/init.d/nfs.server start

7. Using below command we can check the NFS folder is shared or not and also we can ensure which client can access this machine.

hpx:/>/usr/sbin/exportfs -av

shareall -F nfs

Steps involved to access the NFS shared folder to the NFS clients:

1. Now for NFS client configuration i will login on my Linux machine.In my case i will use my Centos machine as a client, You can select your NFS client machine as per your requirement.

2. On client machine, please select the mount point to where we have to mount the NFS shared folder /backup which we exported from NFS Server 10.135.0.27. On my Linux machine, I will mount it on /home/backup.

3. In this step we will verify the list of shares available on client machine. Please use the below "showmount" command to check which NFS shared folder is accessible.

hpx:/>showmount -e 10.135.0.27

export list for 10.135.0.27

/backup

If we get the output, server side export configuration doesnt have any problem between nfs server and client.

3. In next step we will mount the nfs share locally on our desintation mount point folder.

hpx:/>mount 10.135.0.27:/backup /home/backup

4. In final step, you can check the NFS mount folder using "bdf" command. It is show you the mount folder where all existing data is store. For testing purpose you can create any file on /home/backup.

Hope, you will like my this post, it is cover all the installation and configuration part step by step. Please let me know if you encouter any issue during NFS configuration on HP-UX machine.

How to Create Local YUM Repository on CentOS 7 / RHEL 7

In this post, I describes how to setup a local Yum repository on CentOS 7 & RHEL 7 server operating system.

The local YUM repository is the most significant way to perform any type of package installation without any internet connection. If you have to install software, security updates and fixes often in multiple systems in your local network, then having a local repository is an efficient way. 

All required packages are downloaded over the fast LAN connection from your local server, so that it will save your Internet bandwidth and reduces your annual cost of Internet.

Now, please find the step by step method to create a YUM repository on RHEL 7 & CentOS 7.

Mount the Local Media:

In this step we mount our CentOS 7 / RHEL 7 installation DVD. For example, let us mount the installation media on /mnt directory.

#mount -o loop /dev/cdrom /mnt

In my Linux machine i will insert the ISO on cdrom and mount it on /mnt directory.

Copy or Extract the Media:

In this step, we will extract or copy iso files to local machine. For this work we will create a one mount point directory and copy all the packages files from /mnt.

#mkdir /centos

#cp -rvf /mnt/* /centos

So all the packages are copied on the "/centos" directory.

Install repository packages:

In this step, we will create repository but before this we need to install the "createrepo" rpm on the YUM server.

For createrepo, you need to install some dependency rpm which are listed in "Packages" folder.

#rpm -ivh libxml2-python-2.9.1-5.el7_0.1.x86_64.rpm

#rpm -ivh python-deltarpm-3.6-3.el7.x86_64.rpm

#rpm -ivh deltarpm-3.6-3.el7.x86_64.rpm

#rpm -ivh createrepo-0.9.9-23.el7.noarch.rpm

Once these required packages is installed we create the repo using createrepo command.

#createrepo -v /centos/Packages

Remove the Online Repository:

Please remove the old repository from /etc/yum.repos.d directory. In this directory all the default local centOS / RHEL repository are exist.

#rm -rf /etc/yum.repos.d/*

Create Local Repository:

In this step we will create the local repostiory which is always kept as a local. Using this local repo we can install all the packages and their dependency.

#vi /etc/yum.repos.d/local.repo

[Packages]

baseurl=file:///centos/Packages

gpgcheck=0

enable=1

After save the file your local.repo repository has been created. In next step we will enable it.

Enable Local Repository:

After successfully creation of YUM repository we will enable it.

#yum clean all

#yum repolist all

Using this repolist command you can check the newly created and existing repository on the server. After that you can easily install the pacakges using YUM in RHEL 7 & CentOS 7.

How to setup NFS Server on CentOS 7 / RHEL 7

In this post, I would explain you , how to setup NFS server on CentOS 7 & RHEL 7. This step by step installation and configuration method of NFS server is work in Fedora 22 version also.

Network File System is used for to share files and folders between Linux / Unix systems. NFS enables you to mount a remote share locally as well as it allows to have updated files across the share.

Before starting the setup method , we need to understand which service and files are used for NFS setup.

Please find the below services which are used for NFS setup. its must be always runs on operating system.

rpcbind service: The rpcbind server is used to converts RPC program numbers into universal addresses.

nfs-server service:  Its enables the NFS clients to access NFS shares.

nfs-lock / rpc-statd service: these are the recovery services when an NFS server crashes and reboots.

nfs-idmap service: It translates user and group ids into names, and to translate user and group names

into ids.

The mail configuration file for NFS server and client is "/etc/exports". It controls which file systems are exported to remote hosts and specifies options.

Now, we will start the step by step process for setup of NFS server on CentOS 7 / RHEL 7.

NFS Server Setup:

1. First we need to install the NFS packages on the server where we want to setup of NFS server. We can install the required NFS packages using YUM.

#yum install nfs-utils libnfsidmap

It's installed all the required packages on NFS server.

2. Once the packages are installed we will enable and start all the above services which we explain in my post.

#systemctl enable rpcbind

#systemctl enable nfs-server

#systemctl start rpcbind

#systemctl start nfs-server

#systemctl start rpc-statd

#systemctl start nfs-idmapd

You can check the status of all these service by using this command "systemctl status service_name" to ensure all are working fine.

3. Now we will created the shared directory which we want to share for client.

#mkdir /backup

#chmod -R 777 /backup

We can change the permission of NFS folder as per your requirement. In my case I'll provide the read write permession to all NFS client on this shared folder, so they can easily copy and remove the files. Ideally for security purpose we never provide 777 permission.

4. In this step we will make an entry of shared folder and client information , what permission we give to client to access the folder and which client can access the NFS shared folder.

# vi /etc/exports

/backup 10.135.0.27(rw,sync,no_root_squash)

In above command output, you can see the "/backup" is shared NFS server folder and "10.135.0.27" user client have rights to access this shared folder.

Also in brackets if you see the permission parameter which is very important when we setup the NFS setup. Please find the small idea about these permission parameteres.

rw: Writable permission to shared folder

sync:  all changes to the according filesystem are immediately flushed to disk.

no_root_squash: By default, any file request made by user root on the client machine is treated as by user nobody on the server. If no_root_squash is selected, then root on the client machine will have the same level of access to the files on the system as root on the server

5. Now, we will export the shared directories using following command.

# exportfs -r

We can use other syntax as well for this, which is listed below.

exportfs -v : Displays a list of shares files and export options on a server
exportfs -a : Exports all directories listed in /etc/exports
exportfs -u : Unexport one or more directories
exportfs -r : Reexport all directories after modifying /etc/exports

6. Now in above step 5, we configured and installed the NFS server but if firewall is running on your machine then we need to add NFS services in firewall as well.

#firewall-cmd --permanent --zone public --add-service mountd
#firewall-cmd --permanent --zone public --add-service rpc-bind
#firewall-cmd --permanent --zone public --add-service nfs
#firewall-cmd --reload

NFS Client Steup:

1. Once we installed the NFS server, now we will mount the remote file system on NFS client machine. So for this , on client machine we will install the same NFS packages which we installed during NFS server setup.

#yum install nfs-utils libnfsidmap

It's installed all the required packages on NFS client. Once the packages is installed on NFS client machine we will start the "rpcbind" services on client machine.

#systemctl enable rpcbind

#systemctl start rpcbind

2. Now we will mount the NFS shared folder on client machine but before doing that we will check on client machine which NFS server is available.

client# showmount -e 10.135.0.27    (10.135.0.2 is myserver machine IP)

Export list for 10.135.0.27:

/backup      10.135.0.2

So you can able to see on client machine our NFS shared folder is available on 10.135.0.27 NFS server. 

3. In this step , now we will mount this NFS shared folder on NFS client machine, for this we will create a mount point on client machine where we mount the server shared folder.

client# mkdir /mnt/backup

client#mount 10.135.0.27:/backup /mnt/backup

So you can check the mount folder using "df -h" command.

4. To make a permanent entry on client machine so that once you take a reboot of client machine , the shared folder is not umount.

client# vi /etc/fstab

10.135.0.27:/backup/ /mnt/backup nfs rw,sync,hard,intr 0 0

Please make an entry permanent on client machine and save it and take a restart of machine , after reboot once you login you will see the shared folder still available on the client machine.

5. For testing of shared folder, you can create a one file on client machine then check on the server this newly created file is shown on the server folder also.

So, using all these steps you can easily setup the NFS server and client on your machine.

How To Install VNC Server On CentOS 7 & RHEL 7

In this post, you can find the step by step method of installation and configuration of VNC server on CentOS 7 / RHEL 7. VNC server installation on CentOS 7 / RHEL 7 is quite different from older version of linux.

Before moving to installation part, first we need to know what is VNC server and how it is works on Linux environment.

VNC (Virtual Network Computing):

VNC stands for Virtual Network Computing server which allows for remote desktop connection in graphical GUI mode by using their remote client. For VNC client we can use VNC viewer. We can use other VNC client as wll for taking a remote connection of VNC server.  Some packages is required for installation and configuration which we explain during the post.

Step by Step Installation and Configuration method for VNC Server:

First we need to install the required packages on the server. You can install the packages using "YUM" command and if you have source package you can install it. On my machine I have yum repo , so we can install the rpm using YUM.

1. In my machine I am using GNOME desktop, if GNOME desktop is not installed on your machine then you need to install it by using below command.

#yum groupinstall "GNOME Desktop"

Using above command you can install all the packages which are required for desktop version. When you run the above command you can see all listed packages before installation.

2. After installation of GNOME packages we will install tigervnc-server packages which is mandatory for VNC server installation.

#yum install tigervnc-server*

here, "*" sign is used for all dependency, if you use this sign it is automatically installed all dependency. Using above command we can install all the VNC server rpm's.

3. Now we will add VNC user on the server.

#useradd vibhor

In my case I used my name but you can use any name.

4. In CentOS 7,there is change in the vncserver configuration file, becuase in older version of CentOS it was /etc/sysconfig/vncservers and now it have changed in /lib/systemd/system/vncserver@.service

#cp /lib/systemd/system/vncserver@.service /etc/systemd/system/vncserver@:2.service

5. Now we will edit the vncserver file as describe below.

#vi /etc/systemd/system/vncserver@:2.service

[...]

[Service]

Type=forking

# Clean any existing files in /tmp/.X11-unix environment

ExecStartPre=/bin/sh -c '/usr/bin/vncserver -kill %i > /dev/null 2>&1 || :'

#ExecStart=/sbin/runuser -l <USER> -c "/usr/bin/vncserver %i"

#PIDFile=/home/<USER>/.vnc/%H%i.pid

ExecStart=/sbin/runuser -l vibhor -c "/usr/bin/vncserver %i"

PIDFile=/home/vibhor/.vnc/%H%i.pid

ExecStop=/bin/sh -c '/usr/bin/vncserver -kill %i > /dev/null 2>&1 || :'

In the above file, you need to set the user name which use add on the server for access the VNC server. You can add more user on the server but for each user you need to create new service file and in each file you will change the user string.

6. If your firewall is enable on your machine then you need to add VNC server service on the firewall and make a permanent, in my machine it is enable so i will use it.

#firewall-cmd --permanent --zone=public --add-service vnc-server

#firewall-cmd --reload

7.  Now please switch the user from root and start the vnc server for vnc user.

#su - vibhor

vibhor@localhost~]$ vncserver

You will require a password to access your desktops.

Password:<--yourvncpassword

Verify:<--yourvncpassword

xauth:  file /home/vibhor/.Xauthority does not exist

New 'localhost:2 (vibhor)' desktop is localhost:2

Creating default startup script /home/vibhor/.vnc/xstartup

Starting applications specified in /home/vibhor/.vnc/xstartup

Log file is /home/vibhor/.vnc/localhost:2.log

It is creating the file in your home direcotory , if you see the service is startup and working fine.

8. Now please start the all required services for vnc server and make it permanent so once you take a reboot of machine it is not disable. All the service start and enable through root user.

#systemctl daemon-reload

#systemctl enable vncserver@:2.service

#systemctl start vncserver@:2.service

9. Now  go to your workstation or laptop and install the VNC client and connect the server using "vibhor" vnc user. when you run the client it is asking for host name so you will enter the host name and enter the vncuser password after that you can connect the server graphically.