20 Command Line Tools to Monitor Linux Performance

       20 command line tools to  monitor Linux performance

1. Top – Linux Process Monitoring

2. VmStat – Virtual Memory Statistics

3. Lsof – List Open Files

4. Tcpdump – Network Packet Analyzer

5. Netstat – Network Statistics

6. Htop – Linux Process Monitoring

7. Iotop – Monitor Linux Disk I/O

8. Iostat – Input/Output Statistics

9. IPTraf – Real Time IP LAN Monitoring

10. Psacct or Acct – Monitor User Activity

11. Monit – Linux Process and Services Monitoring

12. NetHogs – Monitor Per Process Network Bandwidth

13. iftop – Network Bandwidth Monitoring

14. Monitorix – System and Network Monitoring

15. Arpwatch – Ethernet Activity Monitor

16. Suricata – Network Security Monitoring

17. VnStat PHP – Monitoring Network Bandwidth

18. Nagios – Network/Server Monitoring

19. Nmon: Monitor Linux Performance

20. Collectl: All-in-One Performance Monitoring Tool

RHEL 7 vs RHEL 8

             

RHEL 7 vs RHEL 8:
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Red Hat has become associated to a large extent with its enterprise operating system Red Hat Enterprise Linux . With the acquisition of open-source enterprise middleware vendor JBoss, Red Hat also offers Red Hat Virtualization (RHV), an enterprise virtualization product. Red Hat provides storage, operating system platforms, middleware, applications, management products, and support, training, and consulting services.Red hat includes many container tools in RHEL 8. It brings support for Buildah, Podman, and Skopeo.System management boost up with the composer features. This feature facilitates organizations to build and deploy customRHEL images.RHEL 8 brings support for the Stratis filesystem, file system snapshots, and LUKSv2 disk encryption with Network-BoundDisk Encryption (NBDE).The new Red Hat Enterprise Linux Web Console also enhances the management of RHEL. It enables administrators to deal with bare metal, virtual, local and remote Linux servers.

Default File System

RHEL 7	RHEL 8
XFS	XFS

Kernel Version

RHEL 7	RHEL 8
3.10.0-x	4.18.0-x

Max. RAM Supported

RHEL 7	RHEL 8
12 TB*	24 TB*(* on x86_64 architecture)

DefaultDatabase

RHEL 7	RHEL 8
Maria Db is the default implementation of MySQL in Red Hat Enterprise Linux 7	The following database servers are available in RHEL 8: MySQL 8.0 Maria Db 10.3 PostgreSQL 10 and PostgreSQL SQL 9.6 Redis 5.0

New version of Programming Languages

RHEL 7	RHEL 8
Python 2 ( 2.7.X) PHP 5.4 Ruby 2.0.0	Python PHP 7.2 Ruby 2.5 Node.js 10

General Availability Date of First Major Release

RHEL 7	RHEL 8
2014-06-09 (Kernel Version 3.10.0-123)	2019-05-07 (Kernel Version 4.18.0-80)

Standard/Default Repo Channels

RHEL 7	RHEL 8
Repo ID : rhel-7-server-rpms Repo Name: Red Hat Enterprise Linux 7 Server (RPMs)	Repo ID : rhel-8-for-x86_64- appstream-rpms Repo Name: Red Hat Enterprise Linux for x86_64 – AppStream (RPMs) Repo ID: rhel-8-for-x86_64-baseos- rpms Repo Name: Red Hat Enterprise Linux 8 for x86_64 – BaseOS (RPMs)

Network Time Synchronization

RHEL 7	RHEL 8
Using either ntp or Chronyd	Using only Chronyd The ntp implementation is not supported in RHEL 8

Maximum Supported File Size

RHEL 7	RHEL 8
Max. (individual) file size = 500TiB Max. filesystem size = 500TiB	The maximum supported size of an XFS file system has been increased from 500 TiB to 1024 TiB (This maximum file size is only on 64-bit machines. Red Hat Enterprise Linux does not support XFS on 32-bit machines)

Package/Software Management

RHEL 7	RHEL 8
Yum being used and it is based on version 3.0.x	Package management is done by DNF (YUMv4) Yum is based on DNF technology and yum command provides backward compatibility with YUM v3 beingused in earlier versions The yum command is just asymbolic link to dnf

Change in default network packet filtering

RHEL 7	RHEL 8
The firewalld daemon uses iptables as its default backend	The “nftables” is the default network packet filtering which has replaced earlier “iptables” framework The firewalld daemon now uses nftables as its default backend This would replace the earlier used ‘iptables’, ‘ip6tables’, ‘arptables’ & ‘ebtables’ tools. The ‘nftables’ does provide a single frame work for both IPv4 & IPv6 protocols

Default Display Server

RHEL 7	RHEL 8
X.Org server is the default display server in RHEL 7	The default display server is ‘Wayland’ used by Gnome Display Manager in RHEL 8

Different Version Control Systems available

RHEL 7	RHEL 8
Red Hat Enterprise Linux 7 is distributed with three of the most popular open source revision control systems: Git, SVN, and CVS	RHEL 8 provides the following version control systems:   Git 2.18   Mercurial 4.8   Subversion 1.10 Both Concurrent Versions System (CVS) and Revision Control System (RCS) are not available in RHEL 8

Changes in NFS

RHEL 7	RHEL 8
The default NFS configuration file is ‘/etc/sysconfig/nfs’	The NFS configuration file is “/etc/nfs.conf” Red Hat Enterprise Linux 8 attempts to automatically convert all options from “/etc/sysconfig/nfs” to “/ etc/nfs.conf” when upgrading from RHEL 7 NFS over UDP is no longer supported

Red Hat Certified Engineer (RHCE) Exam Code - EX300

    Red Hat Certified Engineer (RHCE) Exam Code - EX300

Overview:

The performance-based Red Hat Certified Engineer Exam (EX300) RHCE tests to determine if your knowledge, skill, and ability meet those required of a senior system administrator responsible for Red Hat Enterprise Linux (RHEL) systems. Red Hat Certified System Administrator (RHCSA) certification is required to earn Red Hat Certified Engineer (RHCE) certification

About the RHCE Certification:

An RHCE certification is earned by a Red Hat Certified System Administrator (RHCSA) who has demonstrated the knowledge, skill, and ability required of a senior system administrator responsible for Red Hat Enterprise Linux systems

Classroom Training:

*) Review exam objectives for the RHCE Exam.

*) Candidates must have earned their RHCSA certification on the same Red Hat                 Enterprise Linux (RHEL) version to be eligible to become an RHCE

*) The certification exam is performance-based, meaning that candidates must                   Perform  tasks on a live system, rather than answering questions about how one              might perform  those tasks.

*) The hands-on nature of this exam makes real-world experience a critical facet of          preparation.

*)  Exam results are emailed within 3 business days following the exam.

*) A RHCE who is certified on Red Hat Enterprise Linux 6 will be recognized as a             RHCE for 3 calendar years. This certification window can be extended by earning         additional Red Hat credentials