Error in invoking target 'agent nmhs' of make file ins_emagent.mk while installing Oracle database software

Error in invoking target 'agent nmhs' of make file ins_emagent.mk while installing Oracle 11gr2 11.2.0.4.0 on Red Hat Enterprise Linux 7

Problem:

While installing Oracle database software 11.2.0.4.0 on Linux 7 we may encounter this error in between installation:

Error in invoking target 'agent nmhs' of make file 
/u0/app/oracle/product/11.2.0.4.0/sysman/lib/ins_emagent.mk

Cause:

Linking error due to "ins_emagent.mk"

Solution:

To fix edit the ins_emagent.mk file and change the following line in $ORACLE_HOME/sysman/lib/ins_emagent.mk

$(MK_EMAGENT_NMECTL)

to

$(MK_EMAGENT_NMECTL) -lnnz11

and press the retry button again.

Create RPM packages local repository for Oracle Enterprise Linux 7.0 on Virtual Machine

In this blog post I''ll show you how to create local RPM packages repository for Oracle Enterprise Linux 7.0. Let's start.
First of all we need connected Linux 7.0 ISO, go to the machine setting and check connected checkbox, under ISO image file choose Linux 7.0 installation file as shown below

with root user

mkdir -p /mnt/cdrom
mount -t iso9660 -o ro /dev/sr0 /mnt/cdrom

mkdir -p /repo
cd /mnt/cdrom/Packages
cp * /repo/

cd /repo
rpm -Uvh deltarpm-3.6-3.el7.x86_64.rpm
rpm -Uvh python-deltarpm-3.6-3.el7.x86_64.rpm
rpm -Uvh createrepo-0.9.9-23.el7.noarch.rpm

createrepo .
Spawning worker 0 with 4292 pkgs
Workers Finished
Saving Primary metadata
Saving file lists metadata
Saving other metadata
Generating sqlite DBs
Sqlite DBs complete

mv /etc/yum.repos.d/public-yum-ol7.repo /etc/yum.repos.d/public-yum-ol7.repo.bkp

create rhel_repo.repo file under /etc/yum.repos.d/ and write next parameters

vi /etc/yum.repos.d/rhel_repo.repo

[rhel_repo]
name=repo
baseurl="file:///repo/"
gpgcheck=0
enabled=1

now you can check local repository

yum repolist
Loaded plugins: langpacks
rhel_repo                                                                                                                                                                     | 2.9 kB  00:00:00
rhel_repo/primary_db                                                                                                                                                          | 3.8 MB  00:00:00
repo id                                                                                           repo name                                                                                    status
rhel_repo                                                                                         repo                                                                                         4,292
repolist: 4,292

that's all now you have local RPM packages repository for Oracle Enterprise Linux 7.0

How to Change the Hostname of a Linux System

Normally we will set the hostname of a system during the installation process. but if we need to change hostname what can we do?

On any Linux system you can change its hostname with the command
hostname new_name.

[oracle@oel6 ~]$ hostname
oel6
[oracle@oel6 ~]$ hostname aaa
hostname: you must be root to change the host name
[oracle@oel6 ~]$ su - 
Password: 
[root@oel6 ~]# hostname aaa
[root@oel6 ~]# hostname
aaa

This new name will be until the system rebooted. To permanent change in Red Hat base systems we need to change hostname in /etc/sysconfig/network file.

[root@oel6 ~]# vi /etc/sysconfig/network

NETWORKING=yes
HOSTNAME=oel6

and change hostname in file.

that's all.