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Índice de contenidos
DefinicionesLa figura del AdministradorTipos de InstalacionesHerramientasSistemas OperativosConocimientosSAGE Job DescriptionCertificacionesPrincipios y Buenas PrácticasBibliografía
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“Administración” - definición
Administrar
1. Dirigir, gobernar, ejercer la autoridad o el mando.2. Ordenar, disponer, organizar.3. Suministrar, proporcionar o distribuir.4. Graduar o dosificar el uso de algo, para obtener mayor
rendimiento de ello o para que produzca mejor efecto.
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“Sistemas” - definición
Sistema
1. Conjunto de cosas que relacionadas entre sí ordenadamente contribuyen a determinado objeto.
~ operativo1. Programa o conjunto de programas que efectúan la gestión
de los procesos básicos de un sistema informático, y permite la normal ejecución del resto de las operaciones.
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“Informáticos” - definición
Informática
1. Conjunto de conocimientos científicos y técnicas que hacen posible el tratamiento automático de la información por medio de ordenadores.
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“Sistema informático” - definición
Sistema informático
Conjunto interrelacionado de hardware, software y recurso humano que permite almacenar y procesar información.El hardware incluye las computadoras y sus dispositivos.El software incluye el sistema operativo, el firmware y las aplicaciones.El soporte humano incluye al personal técnico (analistas, programadores, operarios, etc.) y a los usuarios....
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La figura del Administrador■ ¿Quién es el administrador?
■ Persona encargada de configurar y administrar el sistema■ Ideal: una persona encargada sólo de la administración■ En ocasiones: compagina su trabajo y el de administración
■ ¿Qué se espera del administrador?■ Amplios conocimientos de todo el sistema: hardware, software, datos,
usuarios, . . .■ Capacidad reconocida para tomar decisiones■ Ambición y espíritu de superación■ Eficacia y moral irreprochables■ Responsabilidad: se trabaja con datos muy importantes, hay un jefe por
encima, . . .
■ El administrador tiene que tener por un lado autoridad y responsabilidad, por otro servicio y cooperación
(BY:) Mª Pilar González Férez @ ditec.um.es
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Como actúa el Administrador■ Estrategias del administrador al realizar una tarea:
■ Planearlo antes de hacer los cambios, haciendo un estudio detallado de los pasos que hay que realizar
■ Hacer los cambios reversibles, haciendo copia de seguridad del sistema o de los ficheros de configuración a modificar
■ Realizar los cambios incrementalmente, probándolos si fuese posible. (De esta manera se localizarán los fallos más fácilmente)
■ Probarlo, probarlo, probarlo, . . . , antes de hacerlo público■ Conocer cómo realmente trabajan las cosas
■ Al realizar una modificación:■ Precaución antes de . . .■ Testear después de . . .
■ Es recomendable tener un cuaderno de bitácora para registrar todos los cambios (p.e. /etc/INFORMACION)
(BY:) Mª Pilar González Férez @ ditec.um.es
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Tareas esenciales del Administrador■ Añadir nuevos usuarios■ Controlar el rendimiento del sistema■ Realizar las copias de seguridad (y restaurarlas...)■ Añadir/eliminar elementos hardware■ Instalar/actualizar software (o desinstalar... )■ Controlar la seguridad del sistema■ Controlar el correcto arranque del sistema■ Monitorización del sistema■ «Localizar» y resolver problemas del sistema■ Resolver dudas de los usuarios■ ...■ ...todo lo cual puede precisar desarrollo software y scripting
(BY:) Mª Pilar González Férez @ ditec.um.es
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Superusuario o Administrador■ Para administrar, existe un usuario privilegiado, que puede realizar cualquier
acción sobre el sistema saltándose toda protección■ En Windows es el Administrador y pertenece al grupo Administrador■ En Unix es el superusuario o root y pertenece al grupo root
■ HOME: /root (en modo singleuser es /)■ Alternativas para administrar:
■ Entrar al sistema como usuario root■ Ejecutar orden su que crea una shell de superusuario■ Ejecutar la orden sudo, que puntualmente ejecuta algo como superusuario
$ whoami $ idmengano uid=1001(mengano) gid=1000(users)$ su $ sudo idPassword: **** password for mengano: ****# whoami uid=0(root) gid=0(root)root $
(BY:) Mª Pilar González Férez @ ditec.um.es
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■ Estaciones de trabajo monousuario:■ Administración sencilla (uno o muy pocos usuarios)■ Administrador == usuario■ Instalaciones “poco críticas”
■ Servidores multiusuario:■ Mayor número de usuarios■ Arbitraje de recursos (limitaciones y privilegios)■ Modificaciones más delicadas
■ Clusters de máquinas:■ Red: problemas de seguridad y mayor complejidad■ Para gran cantidad de máquinas: automatización de tareas■ La complejidad crece sustancialmente
Tipos de instalaciones
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Herramientas de Administración
■ Casi todos los sistemas operativos UNIX tienen su propio conjunto de herramientas de administración:■ admintool (Sun Solaris)■ control-panel (Linux-RedHat)■ Yast (Linux-SuSe)■ smit (IBM AIX)■ sysadmsh (XENIX)
■ La administración de sistemas del “día a día” se hace por medio de estas herramientas
■ Otras operaciones precisan herramientas específicas o programación/scripting ad-hoc
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■Funcionamiento interno del sistema:■ Diseño interno del sistema operativo■ Permite comprender qué hace cada operación, causas y motivos del
funcionamiento del sistema
■Seguridad y comunicaciones:■ En la actualidad los equipos están en red■ Los servicios de red de una máquina son cruciales
■Programación (scripts, perl, awk, ...):■ Automatización de tareas: “Si lo necesitas una vez lo vas a hacer
varias”
■ Instalación de componentes hardware:■ Discos duros, periféricos, ...
■Otros sistemas operativos, servicios de conectividad
Conocimientos del Administrador
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Sistemas Operativos
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Evolución de Unix
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Evolución de Windows
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LISA (antes SAGE)
https://www.usenix.org/lisa■ USENIX special interest group for system administrators:
■ To enhance technical and managerial capabilities of the profession■ To promote activities that advance the state of the art or the community■To providing tools, information, and services to assist system administrators■ To establish standards of professional excellence
(BY:) Robert Nielsen @ csciwww.etsu.edu
SAGE Site levels
SAGE – Site size Small uniform Complex Large complexNumber of computers: <50 computers up to 100 systems >100 computersOperating systems: all running the same
operating systemrunning more than 2 operating systems
potentially running more than one operating system
Number of users: 20 or fewer users up to 100 users >100 or more users
(A computer used only by the administrator does not qualify as a site)
SAGE Level vs. Skillsvs. Level I - Novice Level II - Junior Level III - Intermediate Level IV - Senior
Can explain simple procedures in writing or verbally, has good phone skills
Can train users in applications and OS fundamentals, and writing basic documentation
Can write purchase justifications, train users in complex topics, make internal presentations, and interact positively with upper management. Independent problem solving; self-direction
Can write proposals or papers, acts as vendor liaison, makes presentations to customers/clients/peers, and works closely with upper management
Familiar with OS commands/utilities at a user level - can edit files, use a shell, find users' home directories, navigate through the file system, use i/o redirection, etc.
High skill with OS commands/utilities - can boot/shutdown a machine, can add/remove user accounts; also understands soft and hard links, distinctions between the kernel and the shell, etc.
Is comfortable with most aspects of OS – can configure mail, install/ configure systems, setup printing, manage basic security, install software, use nslookup/dig; also understands paging and swapping, process communication, devices and drivers, file systems, basics of routing, etc.
Understands all aspects of OS – system tuning, client/server programming, design of consistent network-wide file system layouts, etc.
Is able to follow instructions well Can write scripts in some administrative language (Perl, VBScript, shell, etc.)
Ability to write scripts in some administrative language and do minimal debugging and modification of C programs
Ability to program in an administrative language, to port C programs from one platform to another, and to write small C programs Ability to solve problems quickly, often by use of automation
Skill
s:
SAGE Level vs. Background and Othersvs. Level I - Novice Level II - Junior Level III - Intermediate Level IV - Senior
Bac
kgro
und: Two years of college or equivalent
education or experienceOne to three years of system administration experience
Three to five years systems administration experience
More than five years previous systems administration experience
A degree or certificate in computer science or a related field
A degree in computer science or a related field
A degree in computer science or a related field
A degree and publications in computer science or a related field
Previous experience in customer support, computer operations, system administration or another related area; Motivated to advance in the profession
Programming experience in any applicable language
Significant programming background in any applicable language
Extensive programming background in any applicable language
Familiarity with networked/distributed computing environment concepts; for example, can use the route command, add a workstation to a network, and mount remote file systems
Oth
er d
esira
bles
:
SAGE Level vs. Responsabilitiesvs. Level I - Novice Level II - Junior Level III - Intermediate Level IV - Senior
Performs routine tasks under direct supervision
Administers a small site alone or assists in the administration of a larger system; Works under general supervision
Administers a mid-sized site alone or assists in administration of a large site and manages novice system administrators or operators
Works under senior management to design/implement complex networks of machines or manage a large site or network
Acts as a front-line interface to users, accepting trouble reports and dispatching them to appropriate system administrators
Initiates some new responsibilities and helps plan for the future
Establishes/recommends policies on system use and services
Evaluates/recommends purchases; has strong influence on purchasing
Has purchasing authority and responsibility for purchase justificationSupervises system administrators, system programmers, or others of equivalent seniority
App
ropr
iate
resp
onsi
bilit
ies:
SAGE Other skills to considerNetworking Skills Experience configuring file systems, synchronization, automounters, license managers, NIS/NIS+, TCP/IP, high-speed networking, routers, modem pools/terminal servers, etc.Security Experience building firewalls, deploying authentication systems, or applying cryptography; Experience with passwords, uids/gids, permissions, file system integrity, security packagesSite Specialities Experience at sites with over 1000 computers, users, or disk space; Experience coordinating multiple independent computer facilities (for example, working for the central group at a large company or university); Experience with high uptime requirements, disaster recovery, etc.
Heterogeneity Experience Experience working in an environment with more than one operating system Documentation Background in technical publications, documentation, or desktop publishing Databases Experience using relational databases, a database query language, or as a DBAHardware Experience installing and maintaining network cabling, boards and memory, SCSI devices, peripherals, etc; Experience with board or component level diagnosis and Management Budget responsibility; Experience in writing personnel reviews, and ranking processes; Experience in interviewing/hiring Local Environment Experience Experience with the specific OS, applications, languages or with the work done by the users
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Microsoft Certifications
■ MCSE – 7 Exams (4 networking, 1 client, 1 design, 1 elective)
■ MCSA – 4 Exams (2 networking, 1 client, 1 elective)
(BY:) Robert Nielsen @ csciwww.etsu.edu
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■ Red Hat Certified Technician (RHCT)■ Entry-level certification focuses on single-system administration
■ Red Hat Certified Engineer (RHCE)■ Expands the RHCT with a focus on services and security
■ Red Hat Certified Architect (RHCA)■ Five additional endorsements to RHCE, adds enterprise-level
focus, from clustering to deploying systems
■ Red Hat Certified Security Specialist (RHCSS)■ Includes two exams more than RHCA plus an SELinux exam
Red Hat Certifications
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Other Certification/Training
■ Linux Professional Institute (LPI)■ CompTIA■ Novell■ O'Reilly School of Technology
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Mark Burgess' Principles of System Administration
1- Policy is the foundation
2- Predictability (is the goal)
3- Scalability (is often important)
4- Minimum privilege (restriction of unnecessary privilege protects a system from accidental and malicious damage)
4- Corollary: don't work as Administrator/root
5- Communities (each member needs to consider ramifications of actions)
6- Uniformity (increases predictability – may decrease costs)
(BY:) Robert Nielsen @ csciwww.etsu.edu
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Mark Burgess' Principles of System Administration (cont)
7- Variety (is a method of risk management and higher flexibility, may increase costs)
8- Delegation, aka 'Specialization' (specialization allows experts to develop, who can then do tasks more efficiently and more cost effectively)
9- Resource map: A resource map of a site aids the predictability of the system by allowing an administrator to learn about the parts of the system, understand inter-relationships and prepare a contingency plan for expected problems with the specific elements
9b- Resource map: removes ambiguity and increases knowledge of the environment for administrators, users, and managers
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Mark Burgess' Principles of System Administration (cont)
Good ideas for students:* learn to learn independently* systematic and organized work habits* balance between reality (problems happen) vs. Utopia
Bad ideas for students:* expect a single right answer to every problem* get stuck due to frustration* expect the textbook/manual/instructor/guru to be able to accurately and completely answer every question
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■Recomendaciones ITIL (Information TechnologyInfrastructure Library):■Guía de buenas prácticas en servicios TIC.■ Incluye gestión de incidencias, atención a usuarios,
mantenimiento y cambios.
■COBIT (Control Objectives for Information and relatedTechnology):■Certificación otorgada por ISACA/ITGI.■Dividida en objetivos y dominios.
■ ISO/IEC 20000 (Gestión de servicios TIC)
Guías de buenas prácticas
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■ Unix■ Unix System Administration Handbook. Evi Nemeth, Garth Snyder,.
Prentice Hall 4th Edition 2006 ■ Essential System Administration - Help for UNIX System
Administration. Æleen Frisch. O'Reilly - 2nd Edition 1995 ■ The Practice of System and Network Administration. Thomas A.
Limoncelli, Christine Hogan. Addison Wesley 2001
■ Linux■ Linux System Administrator’s Guide (http://tldp.org/LDP/sag)■ Security & Optimizing Linux (http://tldp.org/LDP/solrhe) ■ Linux Network Administrator’s Guide (http://tldp.org/LDP/nag2)
Bibliografía
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■Windows■Windows Server 2008: The Definitive Guide. Jonathan
Hassell. O'Reilly 2008■Active Directory: Designing, Deploying, and Running Active
Directory. Brian Desmond, Joe Richards, Robbie Allen, Alistair G. Loewe-Norris. O'Reilly – 4th Edition 2008
■Windows Administration Resource Kit: Productivity Solutions for IT Professionals. Dan Holme. Microsoft Press 2008
Bibliografía
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Videos
■ TBirdTLFasthttp://vimeo.com/5343590
■ CeSViMahttp://www.youtube.com/watch?v=Vd6IipXAWSU
■ The IT Crowdhttp://vimeo.com/35437594#t=135
