--- title: "Sysadmin roles; improving OS performance" subject: "Operating System" chapter: 9 key: "semester_6/operating_system:sysadmin-roles-os-performance" source: https://www.bctengineer.com/q/semester_6/operating_system/sysadmin-roles-os-performance site: BCT Engineering --- # Sysadmin roles; improving OS performance Operating System · Chapter 9: System Administration - Asked in: 2070 Magh, 4+4 marks; year not given - Answer checked by Claude Opus 5.5 (high effort) on 2026-10-14 - Page: https://www.bctengineer.com/q/semester_6/operating_system/sysadmin-roles-os-performance - Whole chapter: https://www.bctengineer.com/md/semester_6/operating_system/chapter-9 ## Question What are the roles of system administrators for an organization? How can you increase operating system performance if you are selected as a system administrator? ## Short answer Roles cover installing and configuring systems, managing users and security, performing backups, monitoring services, and providing support. To increase OS performance, first identify bottlenecks using tools like top and vmstat, then tune CPU by removing unneeded processes, add RAM to reduce paging, use faster disks or SSD with proper cache tuning, upgrade network links, apply kernel patches, and redistribute heavy jobs to off-peak hours. ## Answer #### Roles of system administrators - **Installing and configuring** hardware, OS, servers and applications. - **User and group management:** accounts, passwords, quotas, permissions. - **Security:** firewall, patches, antivirus, monitoring logs, enforcing policy. - **Backup and recovery:** scheduled backups and disaster recovery. - **Network and service management:** DNS, DHCP, mail, web, file servers. - **Monitoring and tuning:** performance, resources, capacity planning. - **Support and documentation:** solving users' problems and keeping records. - **Automation:** shell scripts and cron jobs for routine tasks. #### Increasing OS performance 1. **Monitor first:** use tools (`top`, `vmstat`, `iostat`, `sar`, Task Manager) to find the bottleneck: CPU, memory, disk or network. 2. **CPU:** kill runaway or unnecessary processes, adjust priorities (`nice`), remove unneeded start-up services and daemons, add CPU/multiprocessors. 3. **Memory:** add RAM to cut paging and thrashing, tune the swap size, reduce memory-hungry programs. 4. **Disk:** keep enough free space, defragment (where needed), use faster disks/SSD or RAID, place swap and busy files on different disks, tune caches and buffers, and choose a suitable disk scheduling algorithm. 5. **Network:** use faster links, balance traffic, caching proxies. 6. **Kernel and software:** tune kernel parameters, apply patches/updates, remove unused software. 7. **Load distribution:** move heavy jobs to off-peak hours with cron, use load balancing across servers. 8. **Quotas and limits** to stop users from using too many resources. The cycle is: measure, find bottleneck, tune, measure again. ## Check yourself The answer's key points as multiple-choice questions, with the correct option and why. 1. What is the first step in increasing OS performance? A. Buy new hardware immediately B. Use tools like top, vmstat, iostat to find the bottleneck (CPU, memory, disk or network) C. Reinstall the operating system D. Delete all user accounts Answer: B. Measuring first identifies the real bottleneck so tuning is targeted. (Key point: Monitor first) 2. Adding RAM improves performance mainly because it: A. Reduces paging and thrashing B. Increases disk capacity C. Speeds up network links D. Removes the need for the CPU Answer: A. More RAM means fewer page faults and less swapping, which cuts paging and thrashing. (Key point: Memory tuning) 3. How can heavy jobs be prevented from slowing users during working hours? A. Run them in peak hours with higher priority B. Move them to off-peak hours using cron and use load balancing C. Kill all background jobs permanently D. Disable the scheduler Answer: B. Scheduling heavy jobs off-peak with cron and spreading load across servers reduces contention. (Key point: Load distribution) 4. Which sequence describes the tuning cycle given in the answer? A. Tune, guess, reinstall B. Measure, find bottleneck, tune, measure again C. Install, ignore, reboot D. Backup, delete, restore Answer: B. Performance tuning is iterative: measure, find the bottleneck, tune, then measure again to check the result. 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