The write below summarize some of the main tasks that administrators are expected to perform. These duties need not necessarily be carried out by a single person, and at many sites the work is distributed among the members of a team. however, at least one person should understand all the components and ensure that every task is performed correctly.
The system administrator creates accounts for new users, removes the accounts of inactive users, and handles all the account-related issues that come up in between (e.g., orgotten passwords and lost key pairs). The process of actually adding and removing accounts is typically automated by a configuration management system or centralized directory service.
Administrators who work with physical hardware (as opposed to cloud or hosted systems) myst install it and configure it to be recognized by the operatinh system. Hardware support chores might range from the simple task of adding a network interface card to configuring a specialized external storage array.
Using tools to automate repetitive and time-consuming tasks increases your efficiency, reduces the liklihood of errors caused by humans, and improves your ability to respond rapidly to changing requirements. Administrators strive to reduce the amount of manual labor needed to keep systems functioning smoothly. Familiarity with scripting languages and automation tools is a large part of the job.
Backing up data and restoring it successfully when required are important administrative tasks. Although backups are time consuming and boring, the frequency of real-worl disasters is simply too high to allow the job to be disregarded. Backup must be executed on a regular schedule and restores must by tested periodically to ensure that they are functioning correctly.
Installing And Upgrading Software
Software must be selected, installed, and configured, often on a variety of operating systems. As patches and secuirty updates are released, they must be tested, reviewed, and incorporated into the local environment without endangering the stability of production systems.
The term “Software delivery” refers to the process of releasing updated version of software – especially software developed in house to downstream users. Continuous delivery takes this process to the next level by automatically releasing sofotware to users at a regular caence as it is developed. Administrators help implement robust delivery process that meet the requirements of the enterprise.
Monitoring around a problem is usually faster than taking the time to document and report it, and users internal to an organization often follow the path of least resistance. External users are more likely to voice their complaints publicly than to open a support inquiry. Administrators can help to prevent both of these outcomes by detecting problems and fixing them before public failurs occur.
Some monitoring tasks include ensuring that web services respond quickly and correctly, collecting and analyzing log files, and keeping tabs on the availability of server resources such as disk space. All of these are excellent opportunities for automation, and a slew of open source and commercial monitoring systems can help sysadmins with these tasks.
Networked systems fail in unexpected and sometimes spectacular fashion. It’s administrators’s job to play mechanic by dianosing problems and calling in subject matter experts as needed. Finding the source of a problem is often more chalenging than resolving it.
Maintaining local documentation
Administrators choose vendors, write scripts, deploy software, and make many other decisions that may not be immediately obvious or intuitive to others. Thorough and accurate documentaation is a belssing for team members who would otherwise need to reverse engineer a system to resolve problems in the middle of the night. A lovingly crafted network diagram is more useful than many paragraphs of text when describing a design.
Vigialntly monitoring security
Administrators are the first line of defense for protecting network attached systems. The administrators must implement a security policy and set up procedures to prevent system from being breached. This responsibility might include only a few basic check for unauthorized access, or it might involve an elaborate network of traps and auditing programs, depending on the contect . System administrators are cautions by nature and are often the primary champions of security across a tehcnical organization.
UNIX and Linux are general purpose operating systems that are well suited to almost any conceivable computing task. Administrators can tailor systems for optimal performance in accord with the needs of users. the available infrastructure, and the services the systems provide. When a server is performing poorly, it is the administrator’s job to investigate its operation and identify areas that need improvement.
Developing Site Policies
For legal and compliance reasons, most sites need policies that govern the acceptable use of computer systems, the management and retention of data, the privacy and security of netwokrs and systems, and other areas of regulatory interest. System administrators often help organizations develop sensible plicies that meet the letter and intent of the law and yet still promote progress and productivity.
Working With Vendors
Most sites rely on third parties to provide a variety of ancillary services and products related to their computing infrastructure. Thes providers might include software developers, cloud infrastructure providers, hosterd software as a service (SAAS) shops, help-desk support staff, consultants, contractors, security experts, and platform or or infrstructure vendors. Administrators may be tasked with selecting vendors, assisting with contract negotiations, and implementing solutions once the paperwork has been completed.
Although helping other people with tehir various problems is rarely included in a system administrator’s job description, thes tasks claim a measurable portion of most administrators workdays. System administrators are bombarded with problems ranging from “It worked yesterday and now it does’nt! Waht did you change ?” to “I spilled coffee on my keyboard” should I pour water on it to wash it out ?”
Source : Unix And Linux System Administration Handbook Fifth Edition