Performance Metrics

Question 1

What are performance metrics used for?

Answer 1

To monitor CPU and process activity.

Question 2

Which package provides performance monitoring tools in Linux?

Answer 2

The sysstat package.

Question 3

What does the sysstat package do?

Answer 3

Collects, reports, and logs system performance data.

Question 4

Which tools are included in sysstat for monitoring?

Answer 4

mpstat and pidstat.

Question 5

What is mpstat used for?

Answer 5

Provides per-processor breakdown of CPU activity.

Question 6

What details does mpstat report?

Answer 6

Time spent in user mode, system mode, I/O wait, and idle time.

Question 7

What is the syntax for mpstat?

Answer 7

mpstat [ -P { cpu | ALL } ] [ interval [ count ] ]

Question 8

What does -P cpu do in mpstat?

Answer 8

Targets a specific core.

Question 9

What does -P ALL do in mpstat?

Answer 9

Targets all cores.

Question 10

What does interval mean in mpstat?

Answer 10

Defines time between samples.

Question 11

What does count mean in mpstat?

Answer 11

Sets number of samples to collect.

Question 12

Example mpstat command?

Answer 12

mpstat -P ALL 2 5

Question 13

What does mpstat -P ALL 2 5 do?

Answer 13

Samples all CPUs every 2 seconds and collects 5 samples.

Question 14

Why use mpstat?

Answer 14

To spot load imbalance across cores and detect spikes in I/O wait.

Question 15

What is pidstat used for?

Answer 15

Monitors resource usage by process.

Question 16

What details does pidstat report?

Answer 16

CPU usage, memory statistics, I/O activity, and thread statistics.

Question 17

What is the syntax for pidstat?

Answer 17

pidstat [ -u ] [ -r ] [ -d ] [ -p pid,… ] [ interval [ count ] ]

Question 18

What does -u do in pidstat?

Answer 18

Displays CPU usage.

Question 19

What does -r do in pidstat?

Answer 19

Shows memory statistics.

Question 20

What does -d do in pidstat?

Answer 20

Reveals I/O activity.

Question 21

What does -p pid do in pidstat?

Answer 21

Specifies process IDs to monitor.

Question 22

Example pidstat command?

Answer 22

pidstat -u -r -d -p 1234 1 3

Question 23

What does pidstat -u -r -d -p 1234 1 3 do?

Answer 23

Monitors process 1234 every second, collects 3 samples, and displays CPU, RAM, and disk usage.

Question 24

Why use pidstat?

Answer 24

To identify resource-heavy processes and enable performance tuning.