When we perform operating system patching on RHEL systems, we will get below error during boot time.
Showing posts with label Operating System. Show all posts
Showing posts with label Operating System. Show all posts
Sunday, 21 January 2024
Saturday, 29 February 2020
How to reset HP iLO password from command line in Linux
If you have lost or forgotten the iLO password than please find the below steps to reset ilo password from command line.
To reset / set the password of the iLO from within the linux operating system on an HP server, the hponcfg utility needs to be installed
Here is some information about hponcfg -
The hponcfg utility is an online configuration tool used to set up and reconfigure the local iLO without requiring a reboot of the server operating system. It can be used to retrieve and change the iLO configuration of the local server from the linux command line.
Please login on the linux machine and create a new xml file
[root@localhost]#vim ilo_password.xml
<RIBCL VERSION="2.0">
<LOGIN USER_LOGIN="x" PASSWORD="x">
<USER_INFO MODE="write">
<MOD_USER USER_LOGIN="Administrator">
<PASSWORD value="XXXXXXXX*"/>
</MOD_USER>
</USER_INFO>
</LOGIN>
</RIBCL>
save the ilo_password.xml file
In above xml file, you just need to set PASSWORD value - XXXXXXX. Please put your new ILO password here.
To load this xml file in ILO, please use hponcfg command
[root@localhost]# hponcfg -w ilo_password.xml
Your iLO password will be reset, now please login in HPE iLO via new password XXXXXXX.
Please let me know in case of any query about this post. Thanks.
Failed to start lsb bring up/down networking in rhel 7
Such type of error we have received after operating system upgradation from redhat linux operating system from version 7.x to version 7.y.
The root cause for error is network manager upgradation during operating system patching.
To troubleshoot this error, please restart the network service and check the status
[root@localhost network-scripts]# systemctl restart network
Job for network.service failed because the control process exited with error code. See "systemctl status network.service" and "journalctl -xe" for details.
[root@localhost network-scripts]# systemctl status network
You can see " Failed to start lsb bring up/down networking" error message
Solution: To resolve such type of network issue, please perform the below steps.
Go to /etc/sysconfig/network-scripts/ directory and list the files.
[root@localhost]# cd /etc/sysconfig/network-scripts/
You can see the ifcfg-lo filename file which you need to removed it.
after remove this file please take a restart of service. Your network service will restart properly without any issue. Also if you have any other duplicate or backup ifcfg file please remove it.
[root@localhost network-scripts]# rm -rf ifcfg-lo
[root@localhost network-scripts]# systemctl restart network
Now try to access the redhat machine via ssh. Please post your comment if you have any query regarding this post.
The root cause for error is network manager upgradation during operating system patching.
To troubleshoot this error, please restart the network service and check the status
[root@localhost network-scripts]# systemctl restart network
Job for network.service failed because the control process exited with error code. See "systemctl status network.service" and "journalctl -xe" for details.
[root@localhost network-scripts]# systemctl status network
You can see " Failed to start lsb bring up/down networking" error message
Solution: To resolve such type of network issue, please perform the below steps.
Go to /etc/sysconfig/network-scripts/ directory and list the files.
[root@localhost]# cd /etc/sysconfig/network-scripts/
You can see the ifcfg-lo filename file which you need to removed it.
after remove this file please take a restart of service. Your network service will restart properly without any issue. Also if you have any other duplicate or backup ifcfg file please remove it.
[root@localhost network-scripts]# rm -rf ifcfg-lo
[root@localhost network-scripts]# systemctl restart network
Now try to access the redhat machine via ssh. Please post your comment if you have any query regarding this post.
Sunday, 29 April 2018
How to install and configure samba server in RHEL 7 or redhat linux 7
Login on Samaba server
Check samba rpm installed or not, if not installed please install it,
[root@localhost ~]# rpm -qa | grep samba
[root@localhost ~]# yum install samba*
Create a directory in root file system which is shared with client.
[root@localhost ~]#mkdir -p /home/testuser/test
Add a new group or can use existing group
To provide access on shared directory,Here we are adding new group called samba
[root@localhost ~]#groupadd samba
Change the group and permission of sharing folder
[root@localhost ~]#chgrp -R samba /home/testuser/test
[root@localhost ~]#chmod -R 777 /home/testuser/test
create user, add into group and set samba password
[root@localhost ~]#useradd testuser
[root@localhost ~]#usermod -G samba testuser
[root@localhost ~]#smbpasswd -a testuser
Now Edit /etc/samba/smb.conf file
Note: Please take a backup of origianl file.
[root@localhost ~]#cd /etc/samba/
[root@localhost ~]#cp -p smb.conf smb.conf.orig
And add the below given contents in last line of /etc/samba/smb.conf file.
vi /etc/samba/smb.conf
[test]
comment = shared-directory
path = /home/testuser/test
public = no
valid users = testuser, @samba
writable = yes
browseable = yes
create mask = 0774
directory mask = 4774
##Edit these lines in /etc/samba/smb.conf . To allow network to reach samba server
interfaces = lo ens32 192.168.1.0/24
hosts allow = 127. 192.168.1.
security = user
passdb backend = tdbsam
netbios name = localhost
server string = Samba Server localhost
workgroup = MYGROUP
log file = /var/log/samba/samba.log
max log size = 50
security = server
Add services in /etc/services files
vi /etc/services
netbios-ns 137/tcp # netbios name service
netbios-ns 137/udp # netbios name service
netbios-dgm 138/tcp # netbios datagram service
netbios-dgm 138/udp # netbios datagram service
netbios-ssn 139/tcp # netbios session service
netbios-ssn 139/udp # netbios session service
Note: Please check these above ports are open from this samba server to client machine
Now start the smb and nmb services.
systemctl start smb.service
systemctl start nmb.service
Enable smb and nmb service at booting of system
systemctl enable smb.service
systemctl enable nmb.service
Note 1: firewalld service not enable on this server so no need to add any rule.
Note 2: selinux is in permissive state so no need to change the selinux security context.
Now login on window machine
and mount this samba share on the server.
\\localhost.redhat.com\test
Check samba rpm installed or not, if not installed please install it,
[root@localhost ~]# rpm -qa | grep samba
[root@localhost ~]# yum install samba*
Create a directory in root file system which is shared with client.
[root@localhost ~]#mkdir -p /home/testuser/test
Add a new group or can use existing group
To provide access on shared directory,Here we are adding new group called samba
[root@localhost ~]#groupadd samba
Change the group and permission of sharing folder
[root@localhost ~]#chgrp -R samba /home/testuser/test
[root@localhost ~]#chmod -R 777 /home/testuser/test
create user, add into group and set samba password
[root@localhost ~]#useradd testuser
[root@localhost ~]#usermod -G samba testuser
[root@localhost ~]#smbpasswd -a testuser
Now Edit /etc/samba/smb.conf file
Note: Please take a backup of origianl file.
[root@localhost ~]#cd /etc/samba/
[root@localhost ~]#cp -p smb.conf smb.conf.orig
And add the below given contents in last line of /etc/samba/smb.conf file.
vi /etc/samba/smb.conf
[test]
comment = shared-directory
path = /home/testuser/test
public = no
valid users = testuser, @samba
writable = yes
browseable = yes
create mask = 0774
directory mask = 4774
##Edit these lines in /etc/samba/smb.conf . To allow network to reach samba server
interfaces = lo ens32 192.168.1.0/24
hosts allow = 127. 192.168.1.
security = user
passdb backend = tdbsam
netbios name = localhost
server string = Samba Server localhost
workgroup = MYGROUP
log file = /var/log/samba/samba.log
max log size = 50
security = server
Add services in /etc/services files
vi /etc/services
netbios-ns 137/tcp # netbios name service
netbios-ns 137/udp # netbios name service
netbios-dgm 138/tcp # netbios datagram service
netbios-dgm 138/udp # netbios datagram service
netbios-ssn 139/tcp # netbios session service
netbios-ssn 139/udp # netbios session service
Note: Please check these above ports are open from this samba server to client machine
Now start the smb and nmb services.
systemctl start smb.service
systemctl start nmb.service
Enable smb and nmb service at booting of system
systemctl enable smb.service
systemctl enable nmb.service
Note 1: firewalld service not enable on this server so no need to add any rule.
Note 2: selinux is in permissive state so no need to change the selinux security context.
Now login on window machine
and mount this samba share on the server.
\\localhost.redhat.com\test
Thursday, 26 April 2018
How to check Operating Systems Version is 64-bit or 32-Bit in AIX and Solaris
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.
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.
Job for nfs-server.service failed because the control process exited with error code. See "systemctl status nfs-server.service" and "journalctl -xe" for details. Resolution
On Red Hat Linux 7 operating system, some time you will get below NFS service failed error message.
"Job for nfs-server.service failed because the control process exited with error code. See "systemctl status nfs-server.service" and "journalctl -xe" for details."
The above error occur when you are taking restart of nfs service.
# systemctl restart nfs.service
Job for nfs-server.service failed because the control process exited with error code. See "systemctl status nfs-server.service" and "journalctl -xe" for details.
Resolution
# systemctl status nfs-server.service
nfs-server.service - NFS server and services
Loaded: loaded (/usr/lib/systemd/system/nfs-server.service; enabled; vendor preset: disabled)
Active: failed (Result: exit-code) since Fri 2018-04-27 09:56:08 IST; 8s ago
Process: 21370 ExecStopPost=/usr/sbin/exportfs -f (code=exited, status=0/SUCCESS)
Process: 21366 ExecStopPost=/usr/sbin/exportfs -au (code=exited, status=0/SUCCESS)
Process: 21362 ExecStop=/usr/sbin/rpc.nfsd 0 (code=exited, status=0/SUCCESS)
Process: 21273 ExecStart=/usr/sbin/rpc.nfsd $RPCNFSDARGS (code=exited, status=0/SUCCESS)
Process: 2714 ExecStartPre=/usr/sbin/exportfs -r (code=exited, status=1/FAILURE)
Main PID: 21273 (code=exited, status=0/SUCCESS)
Apr 27 09:56:07 localhost.redhat.com systemd[1]: Starting NFS server and services...
Apr 27 09:56:08 localhost.redhat.com exportfs[2714]: exportfs: Failed to resolve foobar.com <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<
Apr 27 09:56:08 localhost.redhat.com exportfs[2714]: exportfs: Failed to resolve foobar.com <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<
Apr 27 09:56:08 localhost.redhat.com systemd[1]: nfs-server.service: control process exited, code=exited status=1
Apr 27 09:56:08 localhost.redhat.com systemd[1]: Failed to start NFS server and services.
Apr 27 09:56:08 localhost.redhat.com systemd[1]: Unit nfs-server.service entered failed state.
Apr 27 09:56:08 localhost.redhat.com systemd[1]: nfs-server.service failed.
To resolve such issue you need to follow the below process.
You need to check which NFS version rpm is installed on the server.
#rpm -qa | grep nfs
the above command show you the installed nfs version.
Normally the above error occur due to lower version on nfs, so to resolve the issue you need to upgrade the nfs version.
installed the latest nfs rpm nfs-utils-1.3.0-0.33.el7 or later
#yum install nfs
The above command upgrade the nfs rpm, or you can download the manually rpm file and installed it through rpm -uvh command.
After that restart the nfs service again.
# systemctl restart nfs.service
it is started successfully, you can check the status via below command.
# systemctl status nfs.service
[root@localhost ~]# systemctl status nfs.service
● nfs-server.service - NFS server and services
Loaded: loaded (/usr/lib/systemd/system/nfs-server.service; disabled; vendor preset: disabled)
Drop-In: /run/systemd/generator/nfs-server.service.d
└─order-with-mounts.conf
Active: active (exited) since Thu 2018-04-27 03:47:57 IST; 18h ago
Process: 32477 ExecStart=/usr/sbin/rpc.nfsd $RPCNFSDARGS (code=exited, status=0/SUCCESS)
Process: 32472 ExecStartPre=/bin/sh -c /bin/kill -HUP `cat /run/gssproxy.pid` (code=exited, status=0/SUCCESS)
Process: 32469 ExecStartPre=/usr/sbin/exportfs -r (code=exited, status=0/SUCCESS)
Main PID: 32477 (code=exited, status=0/SUCCESS)
CGroup: /system.slice/nfs-server.service
Apr 26 03:47:57 localhost systemd[1]: Starting NFS server and services...
Apr 26 03:47:57 localhost systemd[1]: Started NFS server and services.
"Job for nfs-server.service failed because the control process exited with error code. See "systemctl status nfs-server.service" and "journalctl -xe" for details."
The above error occur when you are taking restart of nfs service.
# systemctl restart nfs.service
Job for nfs-server.service failed because the control process exited with error code. See "systemctl status nfs-server.service" and "journalctl -xe" for details.
Resolution
# systemctl status nfs-server.service
nfs-server.service - NFS server and services
Loaded: loaded (/usr/lib/systemd/system/nfs-server.service; enabled; vendor preset: disabled)
Active: failed (Result: exit-code) since Fri 2018-04-27 09:56:08 IST; 8s ago
Process: 21370 ExecStopPost=/usr/sbin/exportfs -f (code=exited, status=0/SUCCESS)
Process: 21366 ExecStopPost=/usr/sbin/exportfs -au (code=exited, status=0/SUCCESS)
Process: 21362 ExecStop=/usr/sbin/rpc.nfsd 0 (code=exited, status=0/SUCCESS)
Process: 21273 ExecStart=/usr/sbin/rpc.nfsd $RPCNFSDARGS (code=exited, status=0/SUCCESS)
Process: 2714 ExecStartPre=/usr/sbin/exportfs -r (code=exited, status=1/FAILURE)
Main PID: 21273 (code=exited, status=0/SUCCESS)
Apr 27 09:56:07 localhost.redhat.com systemd[1]: Starting NFS server and services...
Apr 27 09:56:08 localhost.redhat.com exportfs[2714]: exportfs: Failed to resolve foobar.com <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<
Apr 27 09:56:08 localhost.redhat.com exportfs[2714]: exportfs: Failed to resolve foobar.com <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<
Apr 27 09:56:08 localhost.redhat.com systemd[1]: nfs-server.service: control process exited, code=exited status=1
Apr 27 09:56:08 localhost.redhat.com systemd[1]: Failed to start NFS server and services.
Apr 27 09:56:08 localhost.redhat.com systemd[1]: Unit nfs-server.service entered failed state.
Apr 27 09:56:08 localhost.redhat.com systemd[1]: nfs-server.service failed.
To resolve such issue you need to follow the below process.
You need to check which NFS version rpm is installed on the server.
#rpm -qa | grep nfs
the above command show you the installed nfs version.
Normally the above error occur due to lower version on nfs, so to resolve the issue you need to upgrade the nfs version.
installed the latest nfs rpm nfs-utils-1.3.0-0.33.el7 or later
#yum install nfs
The above command upgrade the nfs rpm, or you can download the manually rpm file and installed it through rpm -uvh command.
After that restart the nfs service again.
# systemctl restart nfs.service
it is started successfully, you can check the status via below command.
# systemctl status nfs.service
[root@localhost ~]# systemctl status nfs.service
● nfs-server.service - NFS server and services
Loaded: loaded (/usr/lib/systemd/system/nfs-server.service; disabled; vendor preset: disabled)
Drop-In: /run/systemd/generator/nfs-server.service.d
└─order-with-mounts.conf
Active: active (exited) since Thu 2018-04-27 03:47:57 IST; 18h ago
Process: 32477 ExecStart=/usr/sbin/rpc.nfsd $RPCNFSDARGS (code=exited, status=0/SUCCESS)
Process: 32472 ExecStartPre=/bin/sh -c /bin/kill -HUP `cat /run/gssproxy.pid` (code=exited, status=0/SUCCESS)
Process: 32469 ExecStartPre=/usr/sbin/exportfs -r (code=exited, status=0/SUCCESS)
Main PID: 32477 (code=exited, status=0/SUCCESS)
CGroup: /system.slice/nfs-server.service
Apr 26 03:47:57 localhost systemd[1]: Starting NFS server and services...
Apr 26 03:47:57 localhost systemd[1]: Started NFS server and services.
Tuesday, 24 April 2018
How to install or upgrade VMware Tools on linux server
You need to login on the server where you need to install or upgrade the vmware tool.
Check the status of vmtools from vcenter GUI & Servers.
/etc/vmware-tools/services.sh status
Please follow the below steps to install or upgrade the VMware Tools:-
1. From vsphere select the virtual machine on which vmtools need to be installed and then Choose VM > Install VMware Tools.
2. As root mount the VMware Tools virtual CD-ROM image to /mnt
mount /dev/cdrom /mnt
3. go to /tmp and untar the installation file.
cd /tmp
tar zxf /mnt/VMwareTools-x.0.0-<xxxx>.tar.gz
4. Run the VMware Tools installer:
cd /tmp/vmware-tools-distrib
./vmware-install.pl -d
Unmount of the VMware Tools virtual CD-ROM image is done automatically.
Login to server as root and run below command to start the services:
/etc/vmware-tools/services.sh start
Run below command to check the status of vmtools:
/etc/vmware-tools/services.sh status
Uninstall the vmtools by running below command:
/usr/bin/vmware-uninstall-tools.pl
Login to server as root and run below command to start the services:
/etc/vmware-tools/services.sh start
Run below command to check the status of vmtools:
/etc/vmware-tools/services.sh status
Uninstall the vmtools by running below command:
/usr/bin/vmware-uninstall-tools.pl
Monday, 5 February 2018
How to start/stop and enable/disable Firewall on Redhat 7 Linux system
In RHEL7, to stop/start and enable/disable the firewall is quite different from RHEL6. In Red hat 7 "firewalld" named service we used for local firewall. Please find the below example step by step to check the firewall status.
How to check status of RHEL7 firewall:
[root@localhost ~]# systemctl status firewalld
firewalld.service - firewalld - dynamic firewall daemon
How to check status of RHEL7 firewall:
[root@localhost ~]# systemctl status firewalld
firewalld.service - firewalld - dynamic firewall daemon
Loaded: loaded (/usr/lib/systemd/system/firewalld.service; enabled)
Active: active (running) since Thu 2018-02-05 12:37:47 IST; 0 months 1 days ago
Main PID: 332 (firewalld)
CGroup: /system.slice/firewalld.service
└─332 /usr/bin/python -Es /usr/sbin/firewalld --nofork --nopid
└─332 /usr/bin/python -Es /usr/sbin/firewalld --nofork --nopid
Feb 05 12:37:47 localhost systemd[1]: Starting firewalld - dynamic firewall daemon...
Feb 05 12:37:49 localhost systemd[1]: Started firewalld - dynamic firewall daemon.
In the above status firewall is by default enable on the linux system. It is enable automatically when system restart or on.
How to Stop and Start RHEL7 firewall:
Feb 05 12:37:49 localhost systemd[1]: Started firewalld - dynamic firewall daemon.
In the above status firewall is by default enable on the linux system. It is enable automatically when system restart or on.
How to Stop and Start RHEL7 firewall:
Please use the below commands to start stop the firewall on redhat linux 7 operating system.
[root@localhost ~]# service firewalld stop
Redirecting to /bin/systemctl stop firewalld.service
Stopped firewall will start again after system's reboot.
[root@localhost ~]# service firewalld start
Redirecting to /bin/systemctl start firewalld.service
How to Disable and Enable RHEL7 firewall:
If you want to disable permanently firewall so that after reboot it is not enable again, please use the below command.
[root@localhost ~]# systemctl disable firewalld
rm '/etc/systemd/system/dbus-org.fedoraproject.FirewallD1.service'
rm '/etc/systemd/system/basic.target.wants/firewalld.service'
If you want to enable the firewall again run please use the below command.
[root@localhost ~]# systemctl enable firewalld
ln -s '/usr/lib/systemd/system/firewalld.service' '/etc/systemd/system/basic.target.wants/firewalld.se
Tuesday, 16 January 2018
How to Flush Memory Cache and Buffer Cache on Linux Server
When you run the "free -m" command and get the below output, then you observe free memory section will be low value but comparatively buffers+cache value would be higher.
Now this is not a bad thing actually since your OS has reserved this memory to speed up your most used process by keeping them in the cache. But in case any new process is executed and your system is low on memory then these cache would be automatically released to make space for memory reservation of new processes.
[root@localhost]# free -m
total used free shared buffers cached
Mem: 2345 1234 1145 0 24 400
-/+ buffers/cache: 664 345
Swap: 4032 0 4032
if you want to clear or free cache/buffer memory then you need to run the below command.
[root@localhost]# echo 3 > /proc/sys/vm/drop_caches
These are the different values which you can use with the above command
echo 1 is clearing only page cache
[root@localhost]# echo 1 > /proc/sys/vm/drop_caches
echo 2 is to clear free dentries and inodes
[root@localhost]# echo 2 > /proc/sys/vm/drop_caches
echo 3 is clearing page cache, dentries and inodes
[root@localhost]# echo 3 > /proc/sys/vm/drop_caches
[root@localhost]# free -m
total used free shared buffers cached
Mem: 2345 1234 1145 0 24 400
-/+ buffers/cache: 664 345
Swap: 4032 0 4032
if you want to clear or free cache/buffer memory then you need to run the below command.
[root@localhost]# echo 3 > /proc/sys/vm/drop_caches
These are the different values which you can use with the above command
echo 1 is clearing only page cache
[root@localhost]# echo 1 > /proc/sys/vm/drop_caches
echo 2 is to clear free dentries and inodes
[root@localhost]# echo 2 > /proc/sys/vm/drop_caches
echo 3 is clearing page cache, dentries and inodes
[root@localhost]# echo 3 > /proc/sys/vm/drop_caches
Thursday, 21 December 2017
Multipath command with an examples
In linux operating system device mapping through multipath is widely used. Here, we can give you some example how we will use the multipath commands in Linux server
➤ Normally multipath device has a Word Wide Identifier (WWID), which is globally unique and unchanging.
➤ When new devices are brought under the control of DM-Multipath, the new devices may be seen in three different places under the /dev directory: /dev/mapper/mpathn, /dev/mpath/mpathn, and /dev/dm-n
➤ The devices in /dev/mapper are created early in the boot process. Use these devices to access the multipathed devices, for example when creating logical volumes.
The devices in /dev/mpath are provided as a convenience so that all multipathed devices can be seen in one directory. These devices are created by the udev device manager and may not be available on startup when the system needs to access them.
➤ Normally multipath device has a Word Wide Identifier (WWID), which is globally unique and unchanging.
➤ When new devices are brought under the control of DM-Multipath, the new devices may be seen in three different places under the /dev directory: /dev/mapper/mpathn, /dev/mpath/mpathn, and /dev/dm-n
➤ The devices in /dev/mapper are created early in the boot process. Use these devices to access the multipathed devices, for example when creating logical volumes.
The devices in /dev/mpath are provided as a convenience so that all multipathed devices can be seen in one directory. These devices are created by the udev device manager and may not be available on startup when the system needs to access them.
Note: Do not use these devices for creating logical volumes or filesystems
➤ Any devices of the form /dev/dm-n are for internal use only and should never be used.
Please find the multipath syntax which we used in the Linux operating system.
l -> Display the current multipath configuration gathered from sysfs and the device mapper.
ll -> Display the current multipath configuration gathered from sysfs, the device mapper, and all other available components on the system.
f -> Remove the named multipath device.
F -> Remove all unused multipath devices.
v -> Verbosity level
. 0 no output
. 1 print created devmap names only
. 2 default verbosity
. 3 print debug information
. 0 no output
. 1 print created devmap names only
. 2 default verbosity
. 3 print debug information
d -> Dry run, do not create or update devmaps
r -> Force devmap reload
⧪ How to display the current multipath configuration with all information.
[root@localhost~]# multipath -ll
Dec 21 11:27:17 | multipath.conf line 35, invalid keyword: selector
mpathf (3600c0ff00019e9e9dc94c25801000000) dm-6 HP,MSA 2040 SAN
size=466G features='0' hwhandler='0' wp=rw
`-+- policy='round-robin 0' prio=70 status=active
|- 1:0:0:4 sdg 8:96 active ready running
|- 2:0:0:4 sdj 8:144 active ready running
|- 1:0:1:4 sdq 65:0 active ready running
`- 2:0:1:4 sdt 65:48 active ready running
⧪ How to remove multipath devices with multipath Command
[root@localhost~]# multipath -f mpathf
Note: if we use -F option then it is remove all unused devices.
⧪ How to Force reload device map with multipath Command
[root@localhost~]# multipath -r
⧪ How to display the current multipath configuration with all information.
[root@localhost~]# multipath -ll
Dec 21 11:27:17 | multipath.conf line 35, invalid keyword: selector
mpathf (3600c0ff00019e9e9dc94c25801000000) dm-6 HP,MSA 2040 SAN
size=466G features='0' hwhandler='0' wp=rw
`-+- policy='round-robin 0' prio=70 status=active
|- 1:0:0:4 sdg 8:96 active ready running
|- 2:0:0:4 sdj 8:144 active ready running
|- 1:0:1:4 sdq 65:0 active ready running
`- 2:0:1:4 sdt 65:48 active ready running
⧪ How to remove multipath devices with multipath Command
[root@localhost~]# multipath -f mpathf
Note: if we use -F option then it is remove all unused devices.
⧪ How to Force reload device map with multipath Command
[root@localhost~]# multipath -r
Solaris Server process Monitoring tool- prstat
We have different type of tools and command which are used in Solaris or other Unix system to monitor the system process. But if we are talking about only Sun Solaris server then we have very good process tool which is called "prstat".
In this post, we will find that how prstat is work on the Solaris platform.
⇾ !-[solaris]# prstat
When you run the above command on the command line you will get the below output on the CLI screen which are refreshing in every few seconds and sorting all the information regarding the system resource.
PID USERNAME SIZE RSS STATE PRI NICE TIME CPU PROCESS/NLWP
21322 root 11M 3236K cpu0 59 0 0:00:00 0.0% prstat/1
21323 root 18M 4788K sleep 59 0 0:00:00 0.0% sshd/1
22345 root 10M 2188K sleep 59 0 0:00:00 0.0% bash/1
584 root 13M 3832K sleep 59 0 0:01:59 0.0% nscd/51
154 root 13M 2068K sleep 59 0 0:00:00 0.0% syseventd/18
183 root 1772K 776K sleep 59 0 0:00:13 0.0% utmpd/1
538 root 11M 2572K sleep 59 0 0:00:00 0.0% picld/4
Total: 12 processes, 31 lwps, load averages: 0.00, 0.00, 0.00
This is a quick view of the prstat command but if you wanted to get a different view of the same info, like a summary of what users own these CPU consuming processes
⇾ !-[solaris]# prstat -a
If you run prstat with the -a option (prstat -a) you will get an output similar to the default one, but the last few lines of it will be used for providing a really useful report of the users consuming top system resources.
PID USERNAME SIZE RSS STATE PRI NICE TIME CPU PROCESS/NLWP
21322 root 11M 3236K cpu0 59 0 0:00:00 0.0% prstat/1
21323 root 18M 4788K sleep 59 0 0:00:00 0.0% sshd/1
22345 root 10M 2188K sleep 59 0 0:00:00 0.0% bash/1
NPROC USERNAME SWAP RSS MEMORY TIME CPU
5 root 52M 13M 1.3% 0:00:00 0.0%
50 root 841M 571M 56% 0:22:22 0.0%
2 daemon 17M 4520K 0.4% 0:00:04 0.0%
Total: 12 processes, 31 lwps, load averages: 0.00, 0.00, 0.00
We have different type of syntax which we can used to monitor the Solaris server process which are listed below.
!-[solaris]# prstat -L -> This shows thread per line instead of one process per line
!-[solaris]# prstat -s -> prstat output can be sorted using set of sub-options .sub options are cpu,pri,rss,size,time
In this post, we will find that how prstat is work on the Solaris platform.
⇾ !-[solaris]# prstat
When you run the above command on the command line you will get the below output on the CLI screen which are refreshing in every few seconds and sorting all the information regarding the system resource.
PID USERNAME SIZE RSS STATE PRI NICE TIME CPU PROCESS/NLWP
21322 root 11M 3236K cpu0 59 0 0:00:00 0.0% prstat/1
21323 root 18M 4788K sleep 59 0 0:00:00 0.0% sshd/1
22345 root 10M 2188K sleep 59 0 0:00:00 0.0% bash/1
584 root 13M 3832K sleep 59 0 0:01:59 0.0% nscd/51
154 root 13M 2068K sleep 59 0 0:00:00 0.0% syseventd/18
183 root 1772K 776K sleep 59 0 0:00:13 0.0% utmpd/1
538 root 11M 2572K sleep 59 0 0:00:00 0.0% picld/4
Total: 12 processes, 31 lwps, load averages: 0.00, 0.00, 0.00
This is a quick view of the prstat command but if you wanted to get a different view of the same info, like a summary of what users own these CPU consuming processes
⇾ !-[solaris]# prstat -a
If you run prstat with the -a option (prstat -a) you will get an output similar to the default one, but the last few lines of it will be used for providing a really useful report of the users consuming top system resources.
PID USERNAME SIZE RSS STATE PRI NICE TIME CPU PROCESS/NLWP
21322 root 11M 3236K cpu0 59 0 0:00:00 0.0% prstat/1
21323 root 18M 4788K sleep 59 0 0:00:00 0.0% sshd/1
22345 root 10M 2188K sleep 59 0 0:00:00 0.0% bash/1
NPROC USERNAME SWAP RSS MEMORY TIME CPU
5 root 52M 13M 1.3% 0:00:00 0.0%
50 root 841M 571M 56% 0:22:22 0.0%
2 daemon 17M 4520K 0.4% 0:00:04 0.0%
Total: 12 processes, 31 lwps, load averages: 0.00, 0.00, 0.00
We have different type of syntax which we can used to monitor the Solaris server process which are listed below.
!-[solaris]# prstat -L -> This shows thread per line instead of one process per line
!-[solaris]# prstat -s -> prstat output can be sorted using set of sub-options .sub options are cpu,pri,rss,size,time
!-[solaris]# prstat -t -> It provides complete users resource utilization.
!-[solaris]# prstat -Z -> It provides summary per local zone.
!-[solaris]# prstat -Z -> It provides summary per local zone.
Sunday, 10 December 2017
How to check number of CPU and processor in linux operating system
In this post, we will find all the command using which we can find that how many CPU and processor are used in Linux operating system.
⇾ This command are applicable in both RedHat & CentOS operating machine.
➤ How to check number of processor on operating system.
cat /proc/cpuinfo | grep "physical id" | sort -u | wc -l
Using above command it show you the number of processor which are currently used on server.
➤ How to check number of cores on Linux operating system.
cat /proc/cpuinfo | grep "core id" | sort -u | wc -l
➤ You can used other command as well like "lscpu" to check number of processor and core per socket.
➤ Please find the other command which are also used to check the number of processor and cores in Linux operating system.
cat /proc/cpuinfo | grep 'model name' | uniq
cat /proc/cpuinfo | grep "physical id" | sort -u | wc -l
cat /proc/cpuinfo | grep "core id" | sort -u | wc -l
⇾ This command are applicable in both RedHat & CentOS operating machine.
➤ How to check number of processor on operating system.
cat /proc/cpuinfo | grep "physical id" | sort -u | wc -l
Using above command it show you the number of processor which are currently used on server.
➤ How to check number of cores on Linux operating system.
cat /proc/cpuinfo | grep "core id" | sort -u | wc -l
➤ You can used other command as well like "lscpu" to check number of processor and core per socket.
➤ Please find the other command which are also used to check the number of processor and cores in Linux operating system.
cat /proc/cpuinfo | grep 'model name' | uniq
cat /proc/cpuinfo | grep "physical id" | sort -u | wc -l
cat /proc/cpuinfo | grep "core id" | sort -u | wc -l
Friday, 20 October 2017
How to mount CIFS file system on Linux Operating Server
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.
Tuesday, 18 July 2017
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
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
Thursday, 13 July 2017
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:
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.
[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.
[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=*******
[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.
[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
[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.
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