Operating Systems & Server Functions

System Administration Operating System & Server Functions

• A server is a dedicated service provider, and a client requests those services.
• A client/server network consists of dedicated servers and clients.
• Server-based networks are optimal for resource and data sharing with centralized network security.
• Windows servers 2003 and 2008 typically use client/server networks.

Server Hardware Subsystems

• Primary subsystems include processor, memory (RAM), storage and network connections.
• Failure or overload in any of these subsystems can cause system failure or bottlenecks.
• Processors are integrated chips that perform calculations and logical comparisons.
• Intel and AMD are major processor manufacturers.
• Plan servers for growth, envisioning needs for 3-5 years to avoid frequent re-installation.
• RAM (Random Access Memory) is temporary memory for storing instructions and data accessed by the processor.
• Increasing RAM can improve performance as more instructions and data can be loaded from disks.
• RAM contents are lost when power is turned off, which is why disks are used for long-term storage.
• Storage involves hard drives which were traditionally half electronic/half mechanical devices using magnetic fields on rotating platters
• Now solid-state drives with no mechanical components are used.
• Network connection is necessary for server-client communication.
• Servers need sufficient network bandwidth.
• Minimum speed for network cards is 100 Mbit/second, while servers require 1Gbit/second or faster.

Server Roles

• A server role defines the primary duty a server performs, and a server can have multiple roles.
• Common roles: file services, print services, web services, remote access, application servers, email server, database server, monitoring servers, and threat management servers.

File Services

• Enable users/systems to store, access and manage files on a centralized server/network.
• Examples:
  • Network Attached Storage (NAS) facilitates team collaboration through shared folders.
  • Cloud storage options: Google Drive, Dropbox, or Microsoft OneDrive.
  • File Transfer Protocol (FTP) allows transferring large files between computers, such as via FileZilla.

Print Services

• Allows users to send print jobs, manage printing tasks and control printer access.
• Examples:
  • Print Servers to manage multiple printers like Windows Print Server.
  • Cloud Printing: Google Cloud Print or HP ePrint.
  • Print Queue Management such as PaperCut to track and manage print jobs.

Web and Application Services

• Web services are systems that communicate over the Internet using protocols like HTTP/HTTPS.
• Examples:
  • RESTful APIs allow applications to exchange data in weather APIs or payment gateways.
  • Web hosting services like AWS, GoDaddy or Wix host websites.
  • Web applications like Gmail, YouTube or Slack are accessed through browsers.
• Remote access services permit users to remotely connect to a computer or network.
• Examples:
  • Remote Desktop Protocol (RDP) as in Windows Remote Desktop to access office computers.
  • Virtual Private Network (VPN) such as Cisco AnyConnect or NordVPN for secure connections.
  • Remote support tools such as TeamViewer or AnyDesk for troubleshooting.
• Application servers provide an environment for software access over a network or the Internet.
• Examples:
  • Web application servers: Tomcat WebLogic or GlassFish for hosting web apps.
  • Enterprise applications: SAP or Oracle Applications.

Email, Database, Monitoring, & Threat Management Servers

• Email servers manage the sending, receiving, and storage of email messages.
• Examples:
  • Microsoft Exchange Server for enterprise email.
  • Postfix or Sendmail as open-source email servers.
  • Google Workspace for cloud-hosted email services.
• Database servers stores and manages data for applications or users and responds to queries.
• Examples:
  • SQL-based servers: MySQL, Microsoft SQL Server, PostgreSQL.
  • NoSQL servers: MongoDB, Cassandra.
• Monitoring servers track health, performance and availability of network resources, servers and applications.
• Examples:
  • Nagios & Zabbix monitors network and server performance.
  • Prometheus & Grafana provides system metrics and visualization.
• Threat management servers ensures network and system security by detecting, managing and mitigating threats.
• Examples:
  • Intrusion Detection/Prevention Systems (IDS/IPS): Snort or Suricata.
  • Firewall Servers: pfSense or Palo Alto.
  • Security Information and Event Management (SIEM): Splunk, ArcSight.

Selecting Software and Windows Server Editions

• Software instructs the hardware and provides user interface.
• For servers, select an OS, choose roles, and install additional needed software.
• Windows Server 2008 R2 Foundation is for small businesses with less than 15 users.
• Windows Server 2008 R2 Standard is an advanced platform for business workloads with virtualization, power savings, and manageability.
• Windows Server 2008 R2 Enterprise supports mission-critical workloads, increased RAM, and failover clustering.
• Windows Server 2008 R2 Datacenter delivers an enterprise-class platform for large-scale virtualization.
• Windows Web Server 2008 R2 is designed for Internet-facing servers and equipped with Internet Information Services (IIS) 7.5.

Installation Types

• A clean installation involves installing the OS from scratch on a new or reformatted drive.
  • This provides a fresh start, but requires reinstalling, patching, configuring and copying data, potentially taking hours or days.
• Upgrading involves moving from an older version of Windows to Windows Server 2008 R2
  • Direct upgrades aren't possible from 32-bit to 64-bit architectures, or between languages.

Windows Installation Tools

• Disk cloning software, such as Norton Ghost, can create a sector-by-sector image file of the install.
  • This allows cloning of the operating system to multiple computers quickly
• Attended installations need very little user interaction.
  • It uses an answer file, which is an XML file called autounattend.xml, that stores responses for GUI dialog boxes.
• Windows Deployment Services (WDS) is a Microsoft technology that allows for network-based OS installation and customization using unattended installation scripting files.

Licensing & Updates

• Software costs, including client copies of Windows, Office, and enterprise software, can be significant.
• Licensing options must be consider to get the best price.
• Windows updates, including fixes, patches, service packs and device drivers, should be installed to maintain system stability and security.
• Collections of fixes and patches are released as service packs or cumulative packages.

Initial Server Configuration

• Windows Server 2008 and 2008 R2 include Initial Configuration Tasks for initial setup.
• The Initial Configuration Tasks tool can activate Windows, set time zone, configure networks, provide computer name/domain, update Windows, add roles/features, enable remote desktop, and configure the Windows Firewall.

User Account Control

• User Account Control (UAC) began with Windows Vista and is included with Windows Server 2008 which prevents unauthorized computer changes.
• Administrators are prompted for permission and standard users for an administrator password before actions affecting the computer's operation.
• Standard users in Windows Server 2008 R2 can install updates/drivers, view Windows settings and pair Bluetooth devices without requiring administrative rights.

System Settings

• Some important configurations located in the system settings enables: gathering system information, changing the computer name, adding the computer to a domain, accessing device manager, configuring remote settings, configuring startup/recovery options, and configuring overall performance settings.
• A meaningful name is important to identify computers, accomplished via System settings in Control Panel.
• Computers can be added to a domain.
• A workgroup is a peer-to-peer network with decentralized user accounts stored on individual computers.
• A domain is a logical unit of computers with a security boundary, associated with Microsoft's Active Directory. Security is centralized and controlled by domain controllers.

Remote Access

• Remote Assistance and Remote Desktop allow computer access over a network or the Internet.
• This allows use of a mouse and keyboard to access the desktop, taskbar and start menu of the host computer.
• Designed for support personnel to assist or troubleshoot and allows for interaction with the current session.
• The user shares control of the mouse cursor and shares the same computer screen.
• To ensure security, Remote Assistant must be installed as a feature. It must be enabled in the Remote tab of the System properties dialog box.
• The person must be invited using email or instant message.

Remote Desktop

• After the person accepts the invitation, a two-way encrypted connection will be created.
• To start a Remote Assistance session/Invitation, open the Start Menu, click All Programs, Select Maintenance, and click Windows Remote Assistance.
• Remote Desktop allows a program user to remotely access a server.
• By default, Windows Server 2008 R2 supports two remote desktop connections (three if you count the console mode, which is the active connection.
• Network Level Authentication completes user authentication before establishing a Remote Desktop connection, before a logon screen appears.
• The "allow connections running remote desktop with network level authentication" option relies on Windows 7 or a newer version of Remote Desktop.

Enabling Remote Desktop

• Unlike Remote Assistance, Remote Desktop must be installed but enabled.
• Enable Remote Desktop in System Properties by selecting:
  • "Allow connections from computer running any version of remote desktop (less secure)", or
  • "Allow connections running Remote Desktop with Network Level Authentication (more secure)".

Date, Time & IP Settings

• Ensuring the server has the correct date and time is essential for logging and security purposes.
• Incorrect timestamps may cause secure packets to be denied.

Configuring IP Address Settings

• Servers need IP addresses to communicate within a network.
• Key IP settings:
  • IP address and subnet mask to uniquely identify the computer.
  • Default gateway which is the nearest router that connects to other networks or the Internet.
  • One or more DNS servers enable domain or hostname to IP address translation.

Devices & Drivers

• Device drivers control devices and act as translators between the device, the operating system and programs.
• Microsoft released "Plug and Play" in 1983.
• Plug and Play (PnP) automatically recognizes, configures, then installs the appropriate driver.
• IRQ line numbers are a signal a device sends when ready to accept/send information. Each device must have a unique IRQ number.
• DMA channels involve memory access that doesn't use the processor.
• I/O port addresses are channels for data transfer between a device and the processor. Ports appear as memory addresses to the processor.
• Memory address ranges involve sections of computer memory allocated for a device.

Signed Drivers

• Signed drivers have a digital signature to indicate the software publisher.
• It indicates if a driver has been altered.

Devices and Printers Folder

• It displays quick access to computers and devices such as mobile, USB and network devices.
• Internal: internal disk drives, expansion cards or RAM.
• Legacy: keyboards and mice connected through PS/2 or serial ports.

Windows' Device Manager

• Device Manager gives the user a graphical view of the computers installed hardware.
• It allows the user to see whether Windows recognizes a device and whether it is working properly.

Device Manager Capabilities

• Driver Details: Shows driver files, location, provider, version and digital signer of the file.
• Update Driver: Allows updating of driver software.
• Roll Back Driver: Reverts to a previous driver version; this option is unavailable if there is no previous version installed.
• Disable/Enable: Deactivates or activates the device without uninstalling the driver.
• Uninstall: Removes driver software from the computer.

Microsoft Management Console & Administrative Tools

• MMC is the primary administrative tool for managing Windows and network services as well as a method for creating, saving and opening up Windows provided tools.
• Administrative Tools is a Control Panel folder containing tools for system administrators and advanced users.

Common Administrative Tools

• Component Services: Configures and administers Component Object Model (COM) components.
• Computer Management: Manages local/remote computers via a single desktop tool.
• Data Sources (ODBC): Moves data between different database types.
• Event Viewer: Shows significant events, like program start/stop or security errors.
• iSCSI Initiator: Configures advanced connections between storage devices on a network.
• Local Security Policy: Views and edits Group Policy security settings.
• Performance Monitor: Displays advanced information about the processor, memory, hard disk and network performance.
• Print Management: Manages printers and print servers, and performs administrative task.
• Security Configuration Wizard: Creates a security policy to apply to a server on the network.
• Server Management Console that is capable of managing multiple server roles.
• Services: Manages the computers different background services.
• Share and Storage Management: Manages network shared folder shares and volumes.
• Storage Explorer: Views and manages Fibre Channel and iSCSI fabrics in a storage area network (SAN).
• System Configuration: Identifies problems preventing Windows from running correctly.
• Task Scheduler: Schedules programs/tasks to run automatically.
• Windows Firewall with Advanced Security: Configures advanced firewall settings for local/remote computers.
• Windows Memory Diagnostics: Checks computer memory for proper functioning.
• Windows PowerShell Modules: Its command-line tool and scripting language designed for system administration.
• Windows Server Backup: Backs up and restores the server.

Windows Server Administration

• Computers managed via the Computer Management console include the Server Management console.
• Remote Server Administration Tools (RSAT) is a feature from Windows Server 2008 R2.
• RSAT enables remote management of Windows Server 2008 R2, 2008, and 2003 from a Windows Server 2008 R2 computer. It enables to open and run management tools and snap-ins to manage roles, role services, or features on a remote computer.
• The Remote Server Administration Tools pack includes tools for Active Directory Certificate/Domain/Rights Management Services, DHCP/DNS/Fax/File/Hyper-V Services, Network Policy and Access Services, Print and Document Services, Remote Desktop Services, Web Server (IIS), Windows Deployment Services, BitLocker Drive Encryption Administration Utilities.

Server Roles, Services, & The Registry

• A Server Role is a set of software programs that are performing a specific function.
• A Service is a program that performs a system function to support programs or network service.
• Types of Managed Services:
  • Automatic: starts automatically when the system starts.
  • Automatic (Delayed start): starts automatically approximately 2 minutes afer automatic services.
  • Manual: started manually by user or a dependent service.
  • Disabled: prevents the service being started by system, user or dependent services.
  • Workstation: maintains network connections to access servers with SMB protocol.
• The registry is a secure database that stores Windows hardware/software configuration information and system security policies.
• The registry is used by the Windows kernel, device drivers, setup programs, hardware profiles, and user profiles.
  • HKEY_CLASSES_ROOT: Stores applications.
  • HKEY_CURRENT_USER: Stores current user settings.
  • HKEY_LOCAL_MACHINE: Stores settings of the local computer.
  • HKEY_USERS: Contains subkeys for the HKEY_CURRENT_USER keys for each user profile.
  • HKEY_CURRENT_CONFIG: Is information from runtime.

Managing Storage (IDE/SCSI)

• Integrated Drive Electronics (IDE) is now typically known as ATA
• ATA (parallel ATA) began by Western Digital and Compaq in 1986 for compatible hard drives and CD/DVD drives.
• IDE (Integrated Drive Electronics) is an electronic interface standard defining the connection of multiple storage devices on a computers motherboard.
  • IDE drives (Integrated Drive Electronics) are fast and low-cost drives.
  • Traditional IDE drives are based on the parallel AT attachment (ATA) standard that uses a parallel 40-pin/80-conductor connector.

The Functions of ATA

• COMPARING IDE is a standard interface for connecting storage devices to computers. ✓ Connects hard disk drives (HDDs), solid-state drives (SSDs) and optical drives to computer. ✓ Provides faster data transfer rates and improved performance. ✓ Is used in modern internal HDDs, SSDs, and optical drives.

SCSI

• SMALL COMPUTER SYSTEM INTERFACE (SCSI) is a set of parallel interface standards for attaching printers, disk drives, scanners and other peripherals. The first version (SCSI-1), began by ANSI in 1986, was an 8-bit version with a 5 MBps transfer speed that allowed the user to connect a maximum of 8 devices. The latest version, 16-bit Ultra-640 (Fast-320) SCSI, introduced in 2003 with a 640 MBps transfer speed, connecting 16 devices with a - 12-meter cable length.

SCSI-2

• 8-bit bus, six-meter cable length, 5-10 MBps.
• Connects 8 or 16 devices. 50-pin connector.

Wide SCSI-2

• accommodates the 16-bit bus. 3-meter cable; 20 MBps transfer rate.
• connect 16 devices.
• Fast SCSI-2: 8-bit bus but double the clock speed of SCSI-2 allowing transfers of 10-20 MBps.3-meter cable; connects 8 devices.
• Fast Wide SCSI-2: 6-bit bus; 3-meter cable; 20 MBps; 16 devices.
• Ultra SCSI-3: 8-bit and 16-bit versions, both with 1.5-meter cable length.
  • Support data rates of to MBps and connect 8 devices. The 16-bit version doubled the transfer rate and number of devices.
• Ultra-2 SCSI: 8-bit bus- 12 meters; 40 MBps; 8 devices. Wide Ultra-2 SCSI: 16-bit bus: 12 meters; 80 MBps; 16 devices.

Comparing IDE and SCSI

• SCSI drives offer faster performance and throughput.
• SCSI can support a high drive number than IDE can use.

IDE

• Lower Cost
• Devices: 2 per channel, with 2 channels
• Commonly, EASIER to set up

SCSI

• High Cost
• Devices: High (7-15)
• More difficult to configure

RAID

• RAID (redundant array of independent disks) is a way of storing data and multiple hard disks and solid-state drives to reduce the data loss in the case of a drive failure.
• They combine to form a virtual disk

How Raid Works

• by placing data over many disks and allowing for Overlapped IO allowing performance to reduce.
• High disk numbers and high data rates leads to a low MTBF

RAID Controller

• RAID controllers are used to manage data within multiple storage devices for hard disk drives

Types of RAID

RAID LEVEL METHOD HARDWARE SOFTWARE-MINIMUMHARDWARE 0: Striping , Hardware : 2 1: Mirroring, Hardware/Software, 2 5: Striping & Parity : Hardware/Software,3 6: Stripping & Double Parity:: Hardware,4 10 Striping & Mirroring:: Hardware,4

Common Raid Levels

• RAID 0 This configuration has striping, but no redundancy of data.
• offers the best performance, but it does not provide fault tolerance. RAID 1: Also known as disk mirroring, this configuration consists of at least two drives that duplicate the storage of data.
• There is no striping.
  • Read performance is improved since either disk can be read at the same time. -Write performance is the same as for single disk storage.

More Raid Levels

RAID 2:

• the configuration uses striping across disks, with some disks storing error checking and correcting (ECC) information.
  • RAID 2 also uses a dedicated Hamming code parity.
  • RAID 2 has no advantage over RAID 3 and is no longer used.

RAID 3:

• A technique to use stri[ing , with dedicate drive to storing paritu information.
  • Recovery is accomplished by calculating the exclusive information recorded on the other derives
  • RAID 3 cannot overlap I/O. RAID 3 is best used for multiple long use operations.

Raid 4 and Raid 5

• RAID 4 this uses large stripes, which means a user can read records from any single drive overlapped iO can also be be used for read operations.
• RAID 5: The configuration is on parity and block level striping.
  • Raid 5 requires 3 disks

Finally.. RAID 6 and Raid 7

RAID 6: This technique is similar to RAID 5, but includes a second parity scheme distributed across the drives in the array.

• RAID 7 A nonstandard RAID level based on RAID 3 and RAID 4 that adds caching.