Linux System Status Utilities

Posted byProsoxi.com Webmaster Leave a comment on Linux System Status Utilities

Linux System Status Utilities

This command displays a one line summary showing…

Example: uptime
11:42pm up 18 days, 8:45, 1 user, load average: 0.00, 0.00, 0.00

  • Current time (11.42pm)
  • Number of days since last boot (up 18 days)
  • Number of users logged in (1 user)
  • System utilization for the last 1, 5 and 15 minute intervals (load average

This command will display…

  • All users logged in
  • tty device(line) they are using
  • When they logged in
  • Idle time
  • Where they logged in from

Options:

  • -i display idle time
  • -H print column headings

Example: who -iH

USER LINE LOGIN-TIME IDLE FROM
roger ttyp0 Jun 5 23:27 . (omni)

This command displays a one line summary for the current user listing…

  • user name and number
  • primary group and number
  • other groups and numbersExample: id
    uid=1000(roger) gid=100(users) groups=100(users),16(dialout),40(game)

This command displays statistics on memory usage. The values represent KB’s.

Example…

total used free shared buffers cached
Mem: 63208 61484 1724 27848 1060 49360
-/+ buffers/cache: 11064 52144
Swap: 128516 6500 122016

This command stands for disk usage and will print the size of the current directory and subdirectories in 1 KB sizes.

This command displays information for each file system.

Example: df

Filesystem 1024-blocks Used Available Capacity Mounted on
/dev/sda1 497667 301229 170736 64% /
/dev/sda2 7469935 5721885 1360884 81% /usr

This command lists all shell (environment) variables and their contents for the current user.

This command lists process status. There are many options for this command. Below are the two most common.

Example: ps u (process status for current user)

USER PID %CPU %MEM SIZE RSS TTY STAT START TIME COMMAND
roger 418 0.0 1.7 1808 1124 p0 S 23:27 0:01 -bash
roger 690 0.0 0.5 872 356 p0 R 00:09 0:00 ps u
      • PID = Unique Process ID
      • SIZE = Virtual image size; size of text+data+stack
      • RSS = Resident set size; kilobytes of program in memory
      • TTY = Controlling tty
      • STAT = Information about the status of the process
        • R = runnable
        • S = sleeping
        • D = uninterruptible sleep
        • T = stopped or traced
        • Z = zombie process
        • Second field = W if the process has no resident pages.
        • Third field = N if the process has a positive nice value

Example: ps ax (process status of all processes for all users and system)

This command display a full screen of information of the top processes. It will update automatically until the program is stopped. To stop the display, enter q.

12:26am up 18 days 9:29 1 user load average: 0.00, 0.00, 0.00
39 processes: 38 sleeping, 1 running, 0 zombie, 0 stopped
CPU states: 0.5% user, 0.0% system, 0.0% nice, 99.5% idle
Mem: 63208K av, 60848K used, 2360K free, 271
Swap: 128516K av, 6500K used, 122016K free, 48696K cached
PID USER PRI NI SIZE RSS SHARE STAT LIB %CPU %MEM TIME COMMAND
769 roger 19 0 584 584 428 R 0 0.5 0.9 0:00 top
1 root 0 0 256 232 196 S 0 0.0 0.3 0:02 init
2 root 0 0 0 0 0 SW 0 0.0 0.0 0:03 kflushd
3 root -12 -12 0 0 0 SW< 0 0.0 0.0 0:00 kswapd
31485 root 0 0 288 288 232 S 0 0.0 0.4 0:00 mingetty
428 root 0 0 252 224 196 S 0 0.0 0.3 0:00 mingetty
142 root 0 0 264 208 208 S 0 0.0 0.3 0:00 mingetty
9 root 0 0 224 188 172 S 0 0.0 0.2 0:21 update
61 root 0 0 348 308 256 S 0 0.0 0.4 0:31 syslogd
59 root 0 0 464 412 232 S 0 0.0 0.6 0:00 klogd
130 root 0 0 1192 1092 932 S 0 0.0 1.7 0:00 _upsd
73 root 0 0 836 800 352 S 0 0.0 1.2 0:12 named
87 root 0 0 2484 1756 1612 S 0 0.0 2.7 0:00 httpd
90 at 0 0 288 248 224 S 0 0.0 0.3 0:00 atd
93 root 0 0 324 292 244 S 0 0.0 0.4 0:00 cron
96 root 0 0 308 292 228 S 0 0.0 0.4 0:05 inetd
105 root 0 0 324 292 236 S 0 0.0 0.4 0:00 lpd
31763 root 0 0 412 412 328 S 0 0.0 0.6 0:00 mgetty

System Info – procinfoprocinfo gathers some system data from the /proc directory and prints it formatted on the screen.

Some of the information displayed is

  • Last Boot time
  • Load Average
  • average number of jobs running
  • number of runnable processes
  • total number of processes
  • PID of the last process run (idem)
  • Swap info
  • Memory resources
  • Number of disks
  • IRQ info
  • Installed modules (with the -a or -m option)
  • File Systems (with the -a or -m option)To automatically update the displayed info every 30 seconds

procinfo -fn30
To exit, simply press q

Leave a comment