Lesson 1Memory analysis: free -m, /proc/meminfo, slabtop, smem—interpreting used vs available memory and swap behaviorHere yuh guh analyze memory behavior using free, /proc/meminfo, slabtop, an smem. Di section explain Linux caching, buffers, an reclaim, how fi interpret swap usage, an how fi detect memory leaks, fragmentation, an misconfigured limits.
Reading free -m and understanding cached memoryKey fields in /proc/meminfo for diagnosisUsing slabtop to inspect kernel slab usageUsing smem to attribute memory per processRecognizing swap thrashing and OOM risksLesson 2Network usage and bottlenecks: iftop, nload, ss, netstat, ip -s link, tc, tcpdump—identifying network saturation and problematic connectionsDis section cover diagnosing network usage an bottlenecks using iftop, nload, ss, ip, tc, an tcpdump. Yuh guh learn fi identify saturation, noisy neighbors, connection states, an packet level issues dat contribute to slow applications.
Monitoring live bandwidth with iftop and nloadInspecting sockets and states with ssUsing ip -s link to view interface errorsBasics of tc for shaping and rate limitingTargeted packet capture with tcpdumpLesson 3Storage latency and deeper I/O: blktrace, bpftrace (basic scripts), fio for tests—how to measure and interpret latency and throughputDis section cover storage latency an deeper I/O analysis using blktrace, basic bpftrace scripts, an fio benchmarks. Yuh guh learn how fi measure latency an throughput, interpret queue depth, an distinguish device limits from workload issues.
Understanding latency, IOPS, and throughputUsing blktrace to inspect block I/O patternsIntroductory bpftrace scripts for disk latencyDesigning fio workloads that mimic productionReading fio reports and spotting bottlenecksLesson 4Process investigation: ps, top/htop filters, pgrep, pidstat, nice/renice—how to find CPU- and memory-heavy processesYuh guh learn fi investigate processes wid ps, top or htop filters, pgrep, pidstat, an nice or renice. Di section show how fi identify CPU an memory heavy tasks, track per process I/O, an adjust priorities fi reduce contention.
Listing and filtering processes with psUsing pgrep and pkill safely and preciselyUsing pidstat for per process CPU and I/OFiltering top and htop by user or resourceAdjusting priorities with nice and reniceLesson 5System resource overview: top, htop, vmstat, mpstat, dstat—what each shows and expected output patternsHere yuh guh learn fi read system-wide resource snapshots using tools like top, htop, vmstat, mpstat, an dstat. Di section focus pon understanding CPU, memory, an load metrics, an recognizing normal versus pathological usage patterns.
Key CPU, load, and memory fields in topUsing htop for interactive process analysisvmstat for run queue, swap, and I/O insightmpstat for per-CPU utilization and steal timedstat for combined multi-resource timelinesLesson 6Disk I/O and filesystem checks: iostat, iotop, sar -d, lsblk, df -h, du -sh, tune2fs, xfs_info—detecting I/O bottlenecks and low spaceDis section focus pon disk I/O an filesystem health using iostat, iotop, sar -d, lsblk, df, du, tune2fs, an xfs_info. Yuh guh learn fi detect saturation, queue buildup, filesystem errors, an low space conditions dat degrade performance.
Using iostat to spot busy and slow devicesUsing iotop to find I/O heavy processessar -d for historical disk utilization trendsChecking layout and types with lsblk and dfFinding space hogs with du and inode checksLesson 7System logs and journaling: journalctl (systemd), /var/log/messages, /var/log/syslog, auth logs—what to search for and whyDis section explain how fi use systemd journalctl an classic log files such as /var/log/messages, /var/log/syslog, an authentication logs. Yuh guh learn what patterns fi search for, how fi filter noise, an how logs support root cause analysis.
journalctl basics and useful filtering optionsReading /var/log/messages and /var/log/syslogFinding errors, warnings, and rate-limited eventsAnalyzing authentication and sudo related logsCorrelating log timestamps with incidentsLesson 8Time-based and historical monitoring: sar, sysstat, collectl—collecting and reading historical metrics to correlate eventsYuh guh learn how fi collect an interpret historical metrics using sar, sysstat, an collectl. Di section explain how fi schedule data collection, read time series reports, an correlate performance anomalies wid configuration changes or deployments.
Enabling and configuring sysstat collectionUsing sar for CPU, memory, and I/O historyReading sar network and load average trendsUsing collectl for multi-resource timelinesCorrelating metrics with change windowsLesson 9Kernel and scheduler insights: dmesg, sysctl -a, /proc/sys/vm parameters—what kernel messages and tunables revealHere yuh guh explore kernel an scheduler insights using dmesg, sysctl, an /proc/sys/vm parameters. Di section explain how kernel messages, tunables, an scheduler behavior reveal hardware issues, misconfigurations, an tuning options.
Reading dmesg for hardware and driver issuesListing and querying sysctl tunable valuesKey /proc/sys/vm parameters for memoryScheduler related kernel parameters overviewSafely persisting kernel tuning changesLesson 10Approach to root cause determination: step-by-step decision tree to classify issues as CPU, RAM, disk I/O, or networkDis section present a practical decision tree fi root cause analysis. Yuh guh learn how fi classify incidents as CPU, memory, disk I/O, or network bound, which tools fi run in each branch, an how fi iteratively refine hypotheses using collected evidence.
Initial triage and problem statementClassifying CPU versus I/O bound symptomsDistinguishing memory pressure from leaksIdentifying network versus local bottlenecksIterative hypothesis testing with metrics
