Computer Systems in Business

Computer Systems as Business Solutions

• A company can be viewed as an information system, with technical, human, and economic resources organized in an active manner.
• Information systems manage automated information processing for the company, aiding work and communication.
• IT departments emerged between 1960 and 1970 to tackle issues from automating information processes.
• Integrated systems combine information with corporate strategy via modern tech for designing, manufacturing, and selling.

Objectives of Computer Systems in Companies

• Facilitates the development of company strategies.
• Automates planned processes.
• Computer Systems should be available on time and easily adapt to changes
• Meets internal and external information needs.
• Helps in decision making, creation, and distribution of knowledge.
• Secures the confidentiality, integrity, and availability of information.

Requirements for IT System Acceptance

• Should be economically profitable.
• It must be easy and intelligible.
• Needed to be robust and dependable.
• It must be fast and efficient.
• Should be controlled and secure.
• Must be easy to maintain.
• Implementing an information system involves internal departments, specialized companies, or a hybrid approach.
• IT system can be rejected to avoid destabilizing the company's structure, can be seen as an expense rather than an investment, and the disruption it causes in working methods and staff habits.

Tasks Involved in Implementing an IS (Information System)

• Before implementation involves studying company needs, planning processes, cabling infrastructure, physical deployment of workstations and other devices, software installation, security measures and user training.
• Implantation maintenance involves periodic reviews, resource optimization, fixing faults, implementing new hardware or applications and training users on the changes made.

Classifying IT Systems by Organizational Structure

• Single user: workstation.
• Departmental systems are independent support systems or part of interconnected minicomputers linked to a centralized system.
• Corporate systems encompass the entire company.

Classifying IT Systems by Size/Magnitude

• Supercomputers carry out complex tasks for science, military, or tech, using hundreds of stations with specialized refrigeration. An example is MareNostrum in Barcelona.
• Mainframes are powerful, expensive computers for processing large data, like banking transactions or cloud infrastructure management.
• Servers supply services, and workstations PCs with more features, for dedicated applications.
• Personal computers (PCs) are systems that are used both in home and professional environments and can include desktops, laptops, and minicomputers.
• Thin clients are small computers lacking a hard drive, relying on a server for most tasks, centrally managing data and applications.

Classifying IT Systems by the Type of Information They Process

• Batch processing.
• On-line treatment.
• Real-time systems.

Classifying IT Systems by Use

• General purpose.
• Specialized.

IT Platforms: From Personal to Business Use

• IT platforms are selected based on the applications supported and the intended users.

Desktops

• PCs for office automation: used with file servers, the web, and email.
• Specialized workstations: mass storage servers; industrial equipment.
• Home PCs: application and compute servers.
• Portable.
• Mobile.

PC for the Office

• Applied in offices or SOHO (Small Office/Home Office) environments, using standard or company tools.

PC for the Office Requirements

• Normal and/or low performance is expected.
• Work with 2D graphics at typical resolutions.
• Equipment with ability for web and communications.
• Laptops are used in jobs that need mobility.
• Costs are low to medium.

Workstations

• Specialized equipment with high performance requirements for medicine, engineering, architecture, or graphic design.
• Workstations include multiprocessor systems with advanced graphics, high-level peripherals, substantial memory, and large storage.
• Examples of workstation processors are AMD Ryzen Threadripper and Intel Xeon W-2200 series.

Home PC

• Equipment of medium or high performance with improvements in graphics, RAM, and storage.
• Home PCs are used as office stations or for gaming and accessing the internet. Gamming requirements has provoked a change to satisfy the higher performance requirements of gamming.

Laptops and Tablet-PC

• Laptops replace desktop computers when mobility is needed but have a higher cost due to miniaturization.

Laptops and Tablet-PC Requirements

• Lightweight.
• Long battery life.

Laptops and Tablet-PC Current Equipment

• Tablet-PC systems that would be the Surface series that includes touchscreens, foldables, laptops and desktops.

Mobile

• Mobile devices use operating systems and hardware and integrate communications, agenda, Internet connection, applications, GPS, and office automation.
• Mobile devices have advantages in mobility, but it is short coming for their screen size and performance.

Embedded Systems

• Embedded systems are special computer equipment integrated to perform particular functions in a larger electronic system.
• They use microprocessors with special circuitry and use SBCs (Single Board Computer) to make electronic development easier.
• Embedded systems need robustness for hard environments with very safe software, such as production robots, taximeters, or control systems.

Servers

• Servers are specialized computer systems providing resources or services to other computers (clients).
• Clients consume resources, while servers wait for requests.
• Servers process requests and respond, designed to maximize efficiency.

Types of Servers

• A server is dedicated to executing server programs.
• Web server.
• File server.
• Database server.
• Mail server.
• Print server.
• Proxy server.

Specific Server Requirements

• Performance.
• Reliability.
• Safety.
• Availabilty.
• Scalability.

Mainframes

• Mainframe computers (big iron) are high-end systems for demanding workloads like transaction processing, batch processing, and data analytics.
• Mainframes are used by organizations needing high performance, reliability, and scalability.

Common Applications of Mainframes

• Transaction processing (credit card payments and online orders).
• Batch processing (payroll and billing).
• Data analytics.
• Enterprise Resource Planning ERP systems.
• Healthcare.
• Financial services.

Supercomputers

• Supercomputers are non-commercial computers used for advanced tasks related to science, military, or tech by national/international organizations.
• Made of hundreds of interconnected stations in large, refrigerated rooms for parallel processing and high performance.

General Purpose Servers

• General purpose servers are versatile systems that handle tasks from file storage to running complex applications through powerful processors, ample memory, and large storage.

Common Applications of General Purpose Servers

• File sharing and storage: storing files on a network.
• Email routing and delivery: These are email servers managing mailboxes and spam filtering, involving protocols like POP3 that stores emails to erased, IMAP that interacts with the information, and SMTP that manages outgoing emails.
• Web hosting: responsible for saving information in HTML format which involves protocols like http and https.
• The software products that supply web services includes Nginx, a lightweight and fast web server known for performance and scalability, and Apache HTTP Server, a cross-platform open-source system that is known for its stability, security, and extensibility.

Virtualization Hosts

• Known as hypervisors, these software systems allow running multiple virtual machines (VMs) on a physical server.
• Hosts offer increased resource utilization, flexibility, scalability, reduced hardware and improved disaster recovery; popular types are VMware ESXi, Microsoft Hyper-V, Citrix XenServer, and KVM.

Mass Storage Servers

• It is a system designed to store and manage substantial amounts of data and contains hard drives, SSDs, or tape drives to warehousing, backup, recovery etc.
• Mass storages differ in how they are connected to the network.

Direct Attached Storage (DAS)

• The simplest storage server, with data associated to a server where disks reside, typically external hard drives or RAID arrays that are connected to the computer using a SATA or SAS cable.
• Ideal for businesses wanting simple, inexpensive storage for a single computer; not as efficient as NAS or SAN for sharing data.

Network Attached Storage (NAS)

• A storage attached to a network and accessed by Ethernet that is used to store and share files.
• NAS is dedicated to sharing the capacity of one server with client computers over a TCIP/IP network.
• NAS devices are suitable for small and medium businesses needing simple data storage and sharing.

Storage Area Network (SAN)

• High-performance network dedicated to storage, connecting devices with Fibre Channel or iSCSI, accessing the shared data at the block level.
• SAN function connects the elements quickly, safely, and reliably demanding very high performance.
• It allows scalability and growth but at a higher cost with SAN as a great option for scalable high-performance storage.

RAID (Redundant Array of Independent Disks) Technology

• Data storage tech combining multiple hard drives into a single volume, with advantages depending on its configuration (level).
• RAID tech is not to be considered a replacement for backups as that doesn't protect against accidental file deletion.

RAID 0

• It also can be referred to as striping or split set.
• Data are distributed equally along two or more disks which increasing preformance.
• A failure of any of the disks implies loss of data.
• Well aimed at the applications that need storage at high speed and doesn't need failover like audio or video.

RAID 1

• It replicates the data across multiple drives which provides full redundancy but limiting storage.
• Aligns with databases for assistance to server database with systems that needs information and its replacement would be difficult and expensive.
• High data protection, however is costly along with costing increased consumption of hardware.

RAID 0+1

• Combination of the arrays that give speed and fault tolerance spontaneously.
• It provides good performance and high fault tolerance.
• Very high price with usage of a minimum of 4 drives needing usage for data storage.

RAID 3

• Dedicates a single disk to perform parity storage and requires a minimum of 3 disks where 2 for information and 1 for parity.
• They offer high transfer rates and is reliable at a lower cost than the RAID 1.

RAID 5: Parity Across Disks

• Calculates parity information and its alternative storage by blocks on the assemblys disks.
• They provide fault tolerance but optimize systems capacity that allows for utilization to an amount of 80% disk set capacity.
• Disadvantages includes the use of 3 disks along with good overall performance that leads to less performance with RAID 1.

Server Hardware

• Servers require a demanding set of specialized hardware.

Storage Interfaces

• SCSI (Small Computer System Interface) was a storage interface servers used until SAS was developed.
• Compared to IDE, it had advantages such as faster transfer rates, less CPU resource utilization and it supported more devices per port than IDE.
• SCSI didn't integrate its own connector into the motherboard, requiring an external controller.

SAS (Serial Attached SCSI) Interface

• SAS is serial that transmits data one bit at a time.
• SAS is significantly faster than SCSI and is more reliable.

SAS Supported Topologies

• Point-to-point: one SAS port can connect to one device and one device can be connected per port.
• Expander-based: SAS expanders connect multiple SAS devices to a single SAS port is which the expander manages communication between initiator and targets.
• Port multiplier: They can be used in an SAS-connected storage where multiple drives can share a single SAS port.

Main SAS features

• Serial connection.
• Combines SATA and SCSI advantages.
• Faster speed than SCSI.
• Hot plug.
• SATA compatible.
• Supports up to 128 devices.

Motherboards

• They provide reliability for demanding workloads and can be proprietary specific to manufacturer.
• They are designed to have server-grade processors and contains sockets that has dual or triple number of pins.
• Common for the server motherboards to support large quantities of RAM.
• Server motherboards can support various storage along with SAS(Serial Attached SCSI) and SATA (Serial ATA) connectors.

Processors

• Severs have multiple processors designed for parallel tasks.
• Server-grade processors have error correction memory (ECC), multiple sockets, large caches, advanced power management, and specific instructions for encryption and compression.
• Common server processor families are Intel Xeon Scalable, AMD EPYC, IBM Power Systems, Oracle SPARC and ARM Neoverse.

Memory

• Buffered or registered memory modules are used in systems when reliability is required, which contains built in registers to ensure integrity.

Two of the most common RAM memory modules used in servers

• FB-DIMM (Fully Buffered Dual Inline Memory Module): FB-DIMM architecture introduced an advanced memory buffer (AMB) between the memory controller and the memory module. The serial interface increased the width of the memory without increasing the pin count where its serial form made the previous type obsolete.
• LRDIMM (Load Reduced Dual Inline Memory Module): They avoid power consumption problems induced from the required conversion between serial and parallel signal forms.

Form Factors

• Accommodates hardware in servers, and various forms are used.
• Tower: large, stand-alone units and simple for small businesses with limited space.
• Rack (rack-mount): Designed to be mounted in racks which metal cabinets compact the servers in a datacentre.
• Blade: modular, small servers that are used in a blade chassis sharing the same resource.
• Mainframe: The largest and powerful server for heavy duties.

Power Supply Units

• Designed by special form factors that have good power output, redundant design, high efficiency, efficient cooling, and also hot swappable.

Cooling Systems

• Crucial components that prevent overheating causing component damage and fire hazards.
• Procedures are used to maintain temperature in the components.