ifconfig command not found in centos 7 minimal installation

By default in Centos 7 minimal installation , ifconfig command is not found, so for obtaining this command , first you need to check which packages yum provide for this.

[root@localhost]# yum provides ifconfig

Loaded plugins: fastestmirror
Repository 'Packages' is missing name in configuration, using id
Loading mirror speeds from cached hostfile
Packages/filelists_db                                                                                                                              
No matches found

Note: here no packages is installed on the system.

So, using yum we will install the net-tool rpm which is required for ifconfig command

[root@localhost]# yum install net-tools*

Loaded plugins: fastestmirror
Repository 'Packages' is missing name in configuration, using id
Loading mirror speeds from cached hostfile
Resolving Dependencies
--> Running transaction check
---> Package net-tools.x86_64 0:2.0-0.17.20131004git.el7 will be installed
--> Finished Dependency Resolution

Dependencies Resolved

 Package                  Arch           Version                                   Repository                    Size

Installing:
 net-tools                x86_64         2.0-0.17.20131004git.el7         Packages                        304 k

Transaction Summary
========================================================================
Install  1 Package

Total download size: 304 k
Installed size: 917 k
Is this ok [y/d/N]: y
Downloading packages:
Running transaction check
Running transaction test
Transaction test succeeded
Running transaction
Installing : net-tools-2.0-0.17.20131004git.el7.x86_64                                                                     1/1
Verifying  : net-tools-2.0-0.17.20131004git.el7.x86_64                                                                    1/1

Installed:
net-tools.x86_64 0:2.0-0.17.20131004git.el7

Complete!

Now run the ifconfig command after successfully installed the packages.

[root@localhost]# ifconfig -a
ens33: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 1500
        inet 192.26.12.1  netmask 255.255.0.0  broadcast 192.26.255.255
        inet6 fe80::250:56ff:febf:f6  prefixlen 64  scopeid 0x20<link>
        ether 00:50:56:bf:00:f6  txqueuelen 1000  (Ethernet)
        RX packets 18939  bytes 1251073 (1.1 MiB)
        RX errors 0  dropped 0  overruns 0  frame 0
        TX packets 433  bytes 63109 (61.6 KiB)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

lo: flags=73<UP,LOOPBACK,RUNNING>  mtu 65536
        inet 127.0.0.1  netmask 255.0.0.0
        inet6 ::1  prefixlen 128  scopeid 0x10<host>
        loop  txqueuelen 0  (Local Loopback)
        RX packets 0  bytes 0 (0.0 B)
        RX errors 0  dropped 0  overruns 0  frame 0
        TX packets 0  bytes 0 (0.0 B)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

[root@localhost]# yum provides ifconfig

Loaded plugins: fastestmirror
Repository 'Packages' is missing name in configuration, using id
Loading mirror speeds from cached hostfile
net-tools-2.0-0.17.20131004git.el7.x86_64 : Basic networking tools
Repo: @Packages
Matched from:
Filename: /usr/sbin/ifconfig

How to reset or change root password in AIX Operating System

If you forgotten the root password on AIX server, then please follow the below step by step method to recover or reset the root password.
 

➥ You need to insert the operating system same version media disk on cd/dvd rom and power on the AIX machine.
 

➥ When the screen of icons appears, or you hear a double beep sound from hardware of AIX, please press the F1 key repeatedly until the System Management Services menu appears.
 

➥ Select Multi boot option from the SMS (System Management Services) menu
 

➥ Select Install From option from multi boot screen.
 

➥ Select the device (CD rom) that keep the AIX operating system image and then select Install.
 

➥ Select the AIX version icon from the screen menu.
 

➥ Please describe your current system as the system console by pressing the F1 key and then press Enter.
 

➥ In this step you need to select the number of your preferred language and press Enter. In my case I use global language "English".
 

➥ Once you select the language in this step you need to select Start Maintenance Mode for System Recovery by typing 3 and press Enter.
 

➥ In the second last step you can ignore the messages like that "select Access a Root Volume Group".

A message displays explaining that you will not be able to return to the Installation menus without rebooting if you change the root volume group at this point.
 

➥ Please Type 0 and press Enter.

Type the number of the appropriate volume group from the list and press Enter.

Select Access this Volume Group and start a shell by typing 1 and press Enter.

At the # (number sign) prompt, type the passwd command at the command line prompt to reset the root password.

# passwd
Changing password for "root"
root's New password:
Enter the new password again:
 

➥ In the final step , you need to write everything from the buffer to the hard disk and reboot the system.

sync;sync;sync;reboot

When the login screen appears, the password you set in above step 11 should now permit access to root privileges.

How to use zoneadm command in Solaris Servers

Please find the "zoneadm" commands with an example as describe below.
 

➤ How to Verify a Solaris zone:

To verify the local solaris zone you need to run the below command with syntax.

!-[solaris]#zoneadm -z <zone> verify

Example: !-[solaris]#zoneadm -z sunz01 verify

In this example once you run the above command, if your zone is installed properly without any error then this is not showing you any output, that's means it is verified. After running the command if it is showing a message then you need to check the configuration of this zone.

➤ How to Installing a Solaris zone:

To install the local Solaris zone you need to run the below command with syntax.

!-[solaris]#zoneadm -z <zone> install

Example: !-[solaris]#zoneadm -z sunz01 install

In this example when you run the above command then your local zone has been started for installation. It is installed the local zone using the Solaris repostiory or flar images which you are kept at server location.

➤ How to Ready a Solaris zone:

To move the local zone in ready or maintainance state you need to run the below command.

!-[solaris]#zoneadm -z <zone> ready

Example: !-[solaris]#zoneadm -z sunz01 ready

In this example, when we run the above command then your local zone moved in to ready or maintianance state.

➤ How to Boot a Solaris zone:

To boot the solaris zone on global system, you need to run the below command with syantx.

!-[solaris]#zoneadm -z <zone> boot

Example: !-[solaris]#zoneadm -z sunz01 boot

After running the above command your local solaris zone has been boot successfully if it is not showing any error during boot time. If you see any message during the boot time then please check where is the issue.

➤ How to Reboot a Solaris zone:

To reboot or restart the solaris zone on Solaris server, you need to perform the below command on global zone.

!-[solaris]#zoneadm -z <zone> reboot

Example: !-[solaris]#zoneadm -z sunz01 reboot

Using this command the local zone "sunz01" has been restart again successfully. You need to run this command from global zone only.

➤ How to Shutdown/Halt a Solaris zone:

If you want to shutdown or halt your local zone without login it, then you need to run the below command from global zone.

!-[solaris]#zoneadm -z <zone> halt

Example: !-[solaris]#zoneadm -z sunz01 halt

After running this command local solaris zone state change from running to installed state that's means your server is shutdown now.

➤ How to Uninstall a Solaris zone:

If you want to uninstall any solaris zone then you need to run the below command for uninstall the zone.

!-[solaris]#zoneadm -z <zone> uninstall -F

Example: !-[solaris]#zoneadm -z sunz01 uninstall -F

"-F" syntax is used to uninstall the zone forcefully.

➤ How to Viewing a Solaris zone:

if you want to local zone current status and any other display information you need to run the below command.

!-[solaris]#zoneadm list -icv

 ID NAME       STATUS      PATH               BRAND   IP
   0 global         running        /                        solaris      shared
   1 sunz01        running       /zones/sunz01   solaris      excl
   2 sunz02        running       /zones/sunz02   solaris      excl

Using above command you can check the current status of all installed zones on Solaris server. It is show you the zone path and zone information. All the above command you need to run from Global zone with root privileges

Solaris Package administration in Solaris 10 Operating System

In this article, we will provide all the commands with an example which describe as below.

pkginfo- It displays all software package information.
pkgadd- It installs all software packages to the system.
pkgrm- It removes a package from the system.
pkgchk- It checks package installation state.
pkgtrans- It translates packages from one server format to another.

Commands & Syntax for checking a package information:

For checking a packages information on Solaris 10 operating system we will used the "pkginfo" command. You can find the all command and syntax related to "pkginfo" is listed below.

Please use the below command to display information about installed software packages.

!-[solaris]# pkginfo | more

Please use the below command to view additional information.

!-[solaris]# pkginfo -l | more

Please use the below command to view information of a specific package.

!-[solaris]# pkginfo -l SUNWman

Please use the below command to find how many packages are currently installed.

!-[solaris]# pkginfo | wc -l

To list all installed software packages, please use the below command.

!-[solaris]# more /var/sadm/install/contents

These above commands with their syntax are daily used on Solaris 10 platform.

Commands & Syntax for checking a package installation:

For checking an information about packages are installed or not on the server , we need to use "pkgchk"  command. Please find the below example as describe below.

Please use the below command to check the contents & attributes of a currently installed package.

!-[solaris]# pkgchk SUNWpkgs

Please use the below command to list the all files contained in a software package.

!-[solaris]# pkgchk -v SUNWpkgs

Please use the below commands to find if the contents & attributes of a file have changed since it was installed with its software package.

!-[solaris]# pkgchk -p /etc/shadow 

Please use the below commands to list information about selected files that make up a package.

!-[solaris]# pkgchk -l -p /usr/bin/showrev

If the packages is installed already then in that case "pkgchk" command don't show any output that clear meaning is that packages is already installed on the server.

Commands & Syntax for adding a package software:

For adding a packages on the server, we will used the "pkgadd" command. Please find the below commands and their syntax which is daily used on Solaris operating system.

Please use the below command to add a software packages from DVD. For this you need to move on dvd directory where all the packages are listed.

!-[solaris]# pkgadd -d . SUNWpkgs

Using above command you can add the packages from DVD.

Commands & Syntax for removing a package software:

For removing the packages from the server, we will used "pkgrm" command. Please find the below commands and their syntax as listed below.

Please use the below command to remove the software packages.

!-[solaris]# pkgrm SUNWpkgs

Please use the below command to remove a package from the spool directory.

!-[solaris]# pkgrm -s /export/pkg SUNWldam

Commands & Syntax for translating a packages format:

For translating a packages format from one format to another , we will used the "pkgtrans" command for the same.

Please use the below command to translate a package from file system format in /var/tmp to data stream format.

!-[solaris]# pkgtrans /var/tmp /tmp/SUNWpkgs.pkg SUNWpkgs

Please use the below command to create a data streamed package.

!-[solaris]# pkgtrans -s Product /var/tmp/stream.pkg SUNWpkgg SUNWpkgs

NFS mount on Solaris 11 Non-Global zones systems

In this article, we would learn how we mount folder from one Non-Global zone to another zone on Solaris 11 operating system using network file sharing.

For an example, we can use take a two local zone "sunz01" & "sunz02". We will mount one folder named "/export/backup" from "sunz01" local zone to another zone "sunz02" on "/project/export/data" location.

Step by Step method of NFS mount on Solaris 11:
 

➦ In the first step we will create the directory on "sunz02" zone where we want to mount the folder.

sunz02#mkdir /project/export/data
 

➦ In second step, we will make a configuration for this process. So for this work you need to login on global zone with root access and make an entry on the dfstb configuration file.

sun#vi /etc/dfs/dfstab

share -F nfs -o rw=sunz02 /zones/sunz01/root/export

If you see the above entry, we have provided the read/write access to directory on sunz02 server where we mount the folder from sunz01 local zone.
 

➦ In next step you need to login on sunz02 server and mount the shared folder using below command.

sunz02#mount sun:/zones/sunz01/root/export/backup /project/export/data
 

➦ Once you run the above command the folder is mount from one local zone to another zone temporarily. You can go to the directory and verify that the data which is listed on /export/backup folder is show on sunz02 directory.
 

➦ In the last step you need to restart the NFS service on the global zone so the configuration files and other changes makes affect. But these configuration are available until we are not taking reboot of the zone.

If you have any query regarding this topic, please post your comment here, we will get back to you shortly.

How to mount CIFS file system on Linux Operating server machine

Generally on linux or Unix operating system servers when we are mounting the any other linux machine folder is quite easiy in comparision to mount the window shared folder on linux machine.

Step by Step method for Mount CIFS on Linux Server:
 

➤ In the initial step we will gather all rpm's or packages information which is required for CIFS file system.

[root@localhost]# rpm -qa | grep cifs
cifs-utils-4.8.1-20.el6.x86_64

if you see the above output, this packages is required for CIFS file system on Linux system. So you can install this rpm using rpm command if you have rpm packages on the server otherwise you will install the packages using YUM utility.

[root@localhost]# rpm -ivh cifs-utils-4.8.1-20.el6.x86_64.rpm

if you are using YUM, then please install the packages using below command.

[root@localhost]# yum install cifs-utils*

it is installed all required dependency related to CIFS file system.
 

➤ In this step, we will create the mount point on the server where we need to mount the CIFS file system.

[root@localhost]# mkdir -p /backup/cifs

We will create the above mount directory where i will mount the file system.
 

➤ Now, we will create a CIFS user and assign a password so the user can access mount folder.

[root@localhost]# touch /etc/cifspasswd
[root@localhost]# chmod 600 /etc/cifspasswd

[root@localhost]# vi /etc/cifspasswd

user=castwebsvc
password=*******
 

➤ In this step we need to make a permanent entry of mounted file system so once we reboot the machine mounted file system not umount.

[root@localhost]# vi /etc/fstab

ADD fstab entry :

//WindowsServer/share /mount/point cifs rw,mand,user=USER,password=PASS 0 0

Example :
//192.168.0.1/CAST_data4/AICCodeUpload  /backup/cifs cifs   rw,mand,credentials=/etc/cifspasswd         0 0

You can take an example for your system. Please change the mount point as per your requirement.
 

➤ In the final step you need to mount the file system using below command.

[root@localhost]# mount /backup/cifs
[root@localhost]# mount -a

Using above command the CIFS file system has been mounted successfully

How To Fix “Device eth0 does not seem to be present, delaying initialization” Error

This Ethernet card error is normally occur on Linux operating system like CentOS, Red Hat Linux etc. When you try to up the Ethernet card it is showing you the above topic error.

So in this post, we will provide you the step by step solutions and troubleshoot all the issue related this error.

In the initial step, you will check which Ethernet card is down , for this you can run the "ifconfig -a" command. Using this command you can check how many internet card is present on the server and on which Ethernet card used IP address.

Let's suppose you are using eth0 on your machine, and if this Ethernet card not taking any ip address and now show on your device that means it is down right now, so please try to start Eth0 device as given below command.

[root@localhost]# ifup eth0

Device eth0 does not seem to be present, delaying initialization

If your internet card show such issue that means you have an issue with MAC address. So in this post I would explain you how to resolve such issue.

1. In this step, please check the MAC Addresses are set correctly or not. For checking this you need to go the network card directory "/etc/sysconfig/network-scripts"

[root@localhost]# cd /etc/sysconfig/network-scripts

[root@localhost]# cat ifcfg-eth0

HWADDR=”00:15:5D:00:91:91”

In the configuration file, you can see the current hardware address of eth0 card, I have show you only HWADDR entry of my eth0 file. In this directory you can see if other Ethernet card is present or not. In my Linux machine i have two Ethernet card , please find the below second Ethernet card MAC address.

[root@localhost]# cat ifcfg-eth1

HWADDR=”00:15:5D:00:91:90”

2. Now we will see which link is present on the system currently and which is not active, for this you can use the below command to check the status.

[root@localhost]# ip -o link

1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN \    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00

2: eth1: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc mq state UP qlen 1000\    link/ether 00:15:5D:00:91:90 brd ff:ff:ff:ff:ff:ff

3: eth2: mtu 1500 qdisc   pfifo_fast state UP qlen 1000\ link/ether 00:15:5D:00:91:91 brd ff:ff:ff:ff:ff:ff

Here, no eth1 but there is an eth2 present on the system, so might be problem is that the eth0 is renamed to eth2 but we will confirm with below command.

[root@localhost]# dmesg | grep eth0

udev: renamed network interface eth0 to eth2

udev: renamed network interface rename3 to eth0

From this command it shows that udev rename the network interface, so in the next step we will remove the wrong entry and configure the Ethernet card 

3. Now please open the network rules file to confirm the mac address. Please open this file "/etc/udev/rules.d/70-persistent-net.rules" 

[root@localhost]# cat /etc/udev/rules.d/70-persistent-net.rules

SUBSYSTEM=="net", ACTION=="add", DRIVERS=="?*", ATTR{address}=="00:15:5d:00:91:90", ATTR{type}=="1", KERNEL=="eth*", NAME="eth1"

SUBSYSTEM=="net", ACTION=="add", DRIVERS=="?*", ATTR{address}=="00:15:5d:00:91:91", ATTR{type}=="1", KERNEL=="eth*", NAME="eth2"

SUBSYSTEM=="net", ACTION=="add", DRIVERS=="?*", ATTR{address}=="00:15:5d:00:91:91", ATTR{type}=="1", KERNEL=="eth*", NAME="eth0"

Looks like there are multiple entries for the same MAC address. Removed the incorrect entry and restart the interface using below command.

[root@localhost]# ifup eth0

Now you eth0 card is up and if you are running "ifconfig -a" command you can see the eth0 card with mac address.