How to allocate a large memory space for Informix shared memory segments on Red Hat Linux 3 (RHEL3).
Resolving The Problem
You are using IBM® Informix® Dynamic server (IDS) on on Red Hat Linux 3. When you try to allocate more that 1.8 GB (Gigabytes) of shared memory, the following error message appears in the message log file.
13:52:26 shmat: [ENOMEM]: out of available data space, check system memory parameters (e.g. MAXMEM).
This tutorial only covers general security tips for CentOS 7 which can be used to harden the system. The checklist tips are intended to be used mostly on various types of bare-metal servers or on machines (physical or virtual) that provides network services.
Security and Hardening of CentOS 7
However, some of tips can be successfully applied on general purpose machines too, such as Desktops, Laptops and card-sized single-board computers (Raspberry Pi).
In this guide, we are going to learn how to enforce password complexity policy on CentOS 7/RHEL based derivatives. Our previous guide covered the enforcement of password complexity on Ubuntu 18.04. You can check the same by following the link below;
Similar to our previous guide, we are going to use PAM pwquality modules to enforce password complexity policy on CentOS 7/RHEL based derivatives.
In Ubuntu or Debian based derivatives, we modified the, /etc/pam.d/common-password configuration file. For CentOS 7 or similar derivatives, the /etc/security/pwquality.conf or /etc/pam.d/system-auth configuration file is used.
As our normalcy, make a backup of the configuration file before making changes just in case things go south.