Red Hat Enterprise Linux (RHEL) is a Linux distribution developed by Red Hat and targeted toward the enterprise market. Red Hat Enterprise Linux is released in server versions for x86, x86-64, Itanium, PowerPC and IBM System z, and desktop versions for x86 and x86-64.
SUSE Linux Enterprise Server (SLES) is a Linux-based operating system developed by SUSE. It is designed for servers, mainframes, and workstations but can be installed on desktop computers for testing as well. Major versions are released at an interval of 3–4 years, while minor versions (called “Service Packs”) are released about every 18 months.
Debian is a Linux computer operating system distribution, has access to online repositories that contain over 50,000 software packages making it one of the largest software compilations. As one of the earliest Linux distributions, it was decided that Debian was to be developed openly and freely distributed in the spirit of the GNU Project.
Ubuntu is a Debian-based Linux operating system and distribution for personal computers, smartphones and network servers. Is the most popular operating system running in cloud environments. Development of Ubuntu is led by UK-based Canonical Ltd. that generates revenue through the sale of technical support and other services related to Ubuntu.
CentOS (Community Enterprise Operating System) is a Linux distribution that attempts to provide a free, enterprise-class, community-supported computing platform which aims to be functionally compatible with its upstream source RHEL. Since version 7.0, CentOS officially supports only the x86-64 architecture. AltArch releases of CentOS 7 are available for the IA-32 architecture, Power architecture, and for the ARMv7hl and AArch64 variants of the ARM architecture.
Solaris is a Unix operating system originally developed by Sun Microsystems, is known for its scalability, especially on SPARC systems, and for originating many innovative features such as DTrace, ZFS, Containers, … Solaris supports SPARC-based and x86-based workstations. Versions 1.0 to 4.1.4 were based on BSD, while versions 5.0 and later are based on UNIX System V Release 4.
AIX (Advanced Interactive eXecutive) is a Unix operating system developed by IBM. Is based on UNIX System V with 4.3BSD-compatible extensions and know to only run on IBM hardware. AIX runs on IBM Power, System p, System i, System p5, System i5, eServer p5, eServer pSeries and eServer i5 server product lines, as well as IBM BladeCenter and IBM PureFlex based on Power Architecture technology. It was the first operating system to introduce the idea of a journaling file system, JFS, which allowed for fast boot times since 3.0 version.
MySQL is an open-source relational database management system (RDBMS), is a central component of the LAMP open-source web application software stack (and other “AMP” stacks). The MySQL development project has made its source code available under the terms of the GNU General Public License, as well as under a variety of proprietary agreements. For proprietary use, several paid editions are available, and offer additional functionality.
PostgreSQL is an object-relational database management system (ORDBMS) with an emphasis on extensibility and standards-compliance. It can handle workloads ranging from small single-machine applications to large Internet-facing applications with many concurrent users. It is free and open-source software, released under the terms of the PostgreSQL License, a permissive free-software license.
MongoDB is a Free and open-source NoSQL database. MongoDB avoids the traditional table-based relational database structure in favor of JSON-like documents with dynamic schemas, making the integration of data in certain types of applications easier and faster. MongoDB is developed by MongoDB Inc. and is free and open-source, published under a combination of the GNU Affero General Public License and the Apache License.
Oracle Database (commonly referred to as Oracle) is an object-relational database management system. Produced and marketed by Oracle Corporation who offers term licensing for all Oracle products based either on the number of processors in their target machines or on the number of users. Oracle holds #1 DBMS market share worldwide based on the revenue share ahead.
The JBoss Enterprise Application Platform (or JBoss EAP) is an open-source Java EE-based application server runtime platform used for building, deploying, and hosting highly-transactional Java applications and services. The JBoss Enterprise Application Platform is part of the JBoss Enterprise Middleware portfolio of software. The JBoss Enterprise Application Platform was developed by JBoss, now a division of Red Hat that provides a support subscription for JBoss Enterprise Middleware.
Apache Tomcat, often referred to as Tomcat, is an open-source implementation of the Java Servlet, JavaServer Pages, Java Expression Language and Java WebSocket technologies. Powers numerous large-scale, mission-critical web applications across a diverse range of industries and organizations. Is developed in an open and participatory environment and released under the Apache License version 2.
The Apache HTTP Server is an open-source software that provides a secure, efficient and extensible HTTP server that is in sync with the current HTTP standards. Is a project of The Apache Software Foundation and is the world’s most used web server software. Apache was estimated to serve 46.41% of all active websites and 43.18% of the top million websites.
Nginx is an open-source web server software released under the terms of a BSD-like license. A company of the same name was founded in 2011 to provide support. It can act as a reverse proxy server, load balancer, HTTP cache and can be deployed to serve dynamic HTTP content. Nginx uses an asynchronous event-driven approach to handling requests, it’s modular event-driven architecture can provide more predictable performance under high loads. Nginx was found to be the second most widely used web server.
Xen Project is a hypervisor using a microkernel design, providing services that allow multiple computer operating systems to execute on the same computer hardware concurrently. The University of Cambridge Computer Laboratory developed the first versions of Xen. The Xen Project community develops and maintains Xen Project as free and open-source software, subject to the requirements of the GNU General Public License (GPL), version 2. Xen Project is currently available for the IA-32, x86-64 and ARM instruction sets.
Kernel-based Virtual Machine (KVM) is a virtualization infrastructure for the Linux kernel that turns it into a hypervisor. It was merged into the Linux kernel mainline in kernel version 2.6.20 and requires a processor with hardware virtualization extensions. A wide variety of guest operating systems work with KVM, including many flavours and versions of Linux, BSD, Solaris and Windows.
LXC (Linux Containers) is an operating-system-level virtualization method for running multiple isolated Linux systems (containers) on a control host using a single Linux kernel. LXC combines kernel’s cgroups and support for isolated namespaces to provide an isolated environment for applications. Docker can also use LXC as one of its execution drivers, enabling image management and providing deployment services.
Kubernetes (commonly stylized as k8s) is an open-source container-orchestration system for automating application deployment, scaling, and management. It was originally designed by Google, and is now maintained by the Cloud Native Computing Foundation. It aims to provide a “platform for automating deployment, scaling, and operations of application containers across clusters of hosts”. It works with a range of container tools, including Docker.
Logical Domains (LDoms or LDOM) is the server virtualization technology for SPARC processors. It was first released by Sun Microsystems in April 2007. After the Oracle acquisition of Sun, the product has been re-branded as Oracle VM Server for SPARC from version 2.0 onwards.
Each domain is a full virtual machine with a reconfigurable subset of hardware resources. Domains can be securely live migrated, started, stopped, and rebooted independently. A running domain can be dynamically reconfigured to add or remove CPUs, RAM, or I/O devices without requiring a reboot.
Logical Partitioning (LPAR), is the server virtualization technology for POWER systems. Enables memory, CPU capacity, and I/O interfaces to be moved nondisruptively between LPARs within the same server.
Has been supported by the operating systems AIX on almost all POWER systems. The Linux kernel for POWER also supported DLPAR, but its dynamic reconfiguration capabilities were limited to CPU capacity and PCI devices. In October 2009, Linux finally added the capability to DLPAR memory on POWER systems.
VMware ESXi (formerly ESX) is an enterprise-class, type-1 hypervisor developed by VMware for deploying and serving virtual computers. As a type-1 hypervisor, ESXi is not a software application that one installs in an operating system, it includes and integrates vital OS components, such as a kernel.
After version 4.1, VMware renamed ESX to ESXi. ESXi replaces Service Console with a more closely integrated OS. ESX/ESXi is the primary component in the VMware Infrastructure software suite.
Solaris Containers (including Solaris Zones) is an implementation of operating system-level virtualization technology for x86 and SPARC systems, was included in the first full release of Solaris 10, 2005. It is present in illumos (formerly OpenSolaris) distributions, such as OpenIndiana, SmartOS and OmniOS, as well as in the official Oracle Solaris 11 release.
A Solaris Container is the combination of system resource controls and the boundary separation provided by zones. Zones act as completely isolated virtual servers within a single operating system instance.
Pacemaker is an open source high availability resource manager software. It achieves maximum availability for your cluster services (aka. resources) by detecting and recovering from node and resource-level failures by making use of the messaging and membership capabilities provided by your preferred cluster infrastructure (either Corosync or Heartbeat).
It can do this for clusters of practically any size and comes with a powerful dependency model that allows the administrator to accurately express the relationships (both ordering and location) between the cluster resources.
Virtually anything that can be scripted can be managed as part of a Pacemaker cluster.
The Corosync Cluster Engine is an open source project derived from the OpenAIS project. Is a Group Communication System with additional features for implementing high availability within applications. Is used as a High Availability framework by Pacemaker resource manager and provides an implementation of the Totem Single Ring Ordering and Membership protocol providing the Extended Virtual Synchrony model for messaging and membership.
The mission of the Corosync effort is to develop, release, and support a community-defined, open source cluster executive for use by multiple projects and products.
Heartbeat is a daemon that provides cluster infrastructure (communication and membership) services to its clients. This allows clients to know about the presence of peer processes on other machines and to easily exchange messages with them.
In order to be useful to users, the Heartbeat daemon needs to be combined with a cluster resource manager (CRM) which has the task of starting and stopping the services that cluster will make highly available. Pacemaker is the preferred cluster resource manager for clusters based on Heartbeat.
Cluster manager (CMAN) is a component of the cluster project that handles communications between nodes in the cluster.
In the latest cluster code, cman is just a userland program that interfaces with the OpenAIS membership and messenging system.
In the previous versions, cman was a kernel module whose job was to keep a “heartbeat” message moving throughout the cluster, letting all the nodes know that the others are alive. It also handles cluster membership messages, determining when a node enters or leaves the cluster. RedHat Cluster Suite was based on Rgmanager/CMAN until RHEL7 that was completely replaced by Pacemaker/Corosync.
RGManager is a Cluster Resource Manager (CRM). Running under CMAN (and using the DLM), rgmanager manages and provides failover capabilities for collections of resources called services, resource groups, or resource trees in a cluster. These resource groups are tree-structured, and have parent-child dependency and inheritance relationships within each subtree.
There are many resource types provided with rgmanager; the most important being the service resource type.
RedHat Cluster Suite was based on Rgmanager/CMAN until RHEL7 that was completely replaced by Pacemaker/Corosync.
Galera Cluster for MySQL is a true Multi-Master Cluster based on synchronous replication. It’s an easy-to-use, high-availability solution, which provides high system up-time, no data loss and scalability for future growth.
Solaris Cluster (sometimes Sun Cluster or SunCluster) is a high-availability cluster software product for Solaris, originally created by Sun Microsystems. It is used to improve the availability of software services. Sun Cluster operates by having redundant computers or nodes where one or more computers continue to provide service if another fails. Nodes may be located in the same data center or on different continents.
Solaris Cluster is an example of kernel-level clustering software. Some of the processes it runs are normal system processes on the systems it operates on, but it does have some special access to operating system or kernel functions in the host systems.
IBM PowerHA (formerly HACMP) is IBM’s solution for high-availability clusters on the AIX Unix and Linux for IBM System p platforms and stands for High Availability Cluster Multiprocessing. IBM’s HACMP product was first shipped in 1991.
PowerHA can run on up to 32 computers or nodes, each of which is either actively running an application (active) or waiting to take over when another node fails (passive). Data on file systems can be shared between systems in the cluster.
Nagios, now known as Nagios Core, is a free and open source computer-software application that monitors systems, networks and infrastructure.
It offers monitoring and alerting services for servers, switches, applications and services. It alerts users when things go wrong and alerts them a second time when the problem has been resolved. Nagios was originally designed to run under Linux, but it also runs well on other Unix variants.
Nagios supports diferent agents: Nagios Remote Plugin Executor (NRPE), Nagios Remote Data Processor (NRDP), NSClient++, …
Network UPS Tools (NUT) is a suite of software component designed to monitor power devices, such as uninterruptible power supplies, power distribution units, solar controllers and servers power supply units. Many brands and models are supported and exposed via a network protocol and standardized interface.
NUT provides many control and monitoring features, with a uniform control and management interface.
Mod-Gearman is a Nagios addon which extends Nagios to run scalable and distributed setups. Worker nodes can be placed all over your network while keeping the simplicity of a central configuration. Mod-Gearman can even help to reduce the load on a single Nagios host, because of its smaller and more efficient way of executing host and servicechecks.
DRLM is a Centralized Management Open Source solution for small-to-large Disaster Recovery implementations using ReaR.
Is an easy-to-use software to manage your growing ReaR infrastructure. It offers all needed tools to efficiently manage your GNU/Linux disaster recovery backups, reducing Disaster Recovery management costs.
DRLM acts as a central scheduling system for all ReaR installations. Is able to start rear backups remotely and store the rescue-boot/backup in DR images easily managed by DRLM.
Relax-and-Recover is the leading Open Source bare metal disaster recovery and system migration solution. It is a modular framework with many ready-to-go workflows for common situations.
Relax-and-Recover produces a bootable image. This image can repartition the system. Once that is done it initiates a restore from backup. Restores to different hardware are possible. Relax-and-Recover can therefore be used as a migration tool as well.
OpenLDAP is a free, open source implementation of the Lightweight Directory Access Protocol (LDAP) developed by the OpenLDAP Project. It is released under its own BSD-style license called the OpenLDAP Public License.
LDAP is a platform-independent protocol. Several common Linux distributions include OpenLDAP Software for LDAP support.
Ldap Synchronization Connector (LSC) synchronize data from any data source including databases, LDAP directories or files by reading, transforming and comparing these data between the source and the target referentials. These connectors can then be used to continuously synchronize a data source to a directory. It offers a powerful transformation engine, based on a scripting language, to easily manipulate data on the fly.
LSC is an open source project written in Java, available under the BSD license.
Distributed Replicated Block Device (DRBD) software is a distributed replicated storage system for the Linux platform. It is implemented as several userspace management applications and some shell scripts and is normally used on high availability (HA) clusters (version 8.4) and also used as Software Defined Storage (SDS) since it’s version 9.0.
The DRBD software is free software released under the terms of the GNU General Public License version 2.
COMSTAR is an open-source project that allows any Solaris, OpenIndiana, … servers to become a block-based storage device. The acronym stands for COmmon Multiprotocol SCSI TARget. The project is the world’s first open-source enterprise-class target framework. The framework allows all SCSI device types (tape, disk, SES, and so on) to be connected to any transport (Fibre Channel, iSCSI, iSER, SAS, FCoE) with concurrent access to all LUNs (Logical Unit Numbers) and a single point of management.