1 / 55

CIS 191 - Lesson 12

CIS 191 - Lesson 12. System Monitoring. CIS 191 - Lesson 12. ps command. CIS 191 - Lesson 12. Process Information. Just a few of types of information kept on a process. Use man ps to see a lot more. CIS 191 - Lesson 12. Process Information. [ rsimms@opus ~]$ ps

stephanie-snider
Télécharger la présentation

CIS 191 - Lesson 12

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. CIS 191 - Lesson 12 System Monitoring

  2. CIS 191 - Lesson 12 ps command

  3. CIS 191 - Lesson 12 Process Information Just a few of types of information kept on a process. Use man psto see a lot more.

  4. CIS 191 - Lesson 12 Process Information [rsimms@opus ~]$ ps PID TTY TIME CMD 6204 pts/6 00:00:00 bash 6285 pts/6 00:00:00 ps [rsimms@opus ~]$ [rsimms@opus ~]$ ps -a PID TTY TIME CMD 6173 pts/0 00:00:00 man 6176 pts/0 00:00:00 sh 6177 pts/0 00:00:00 sh 6182 pts/0 00:00:00 less 6294 pts/6 00:00:00 ps [rsimms@opus ~]$ Show just my processes Show all processes with a tty

  5. CIS 191 - Lesson 12 Process Information [rsimms@opus ~]$ ps -a PID TTY TIME CMD 6173 pts/0 00:00:00 man 6176 pts/0 00:00:00 sh 6177 pts/0 00:00:00 sh 6182 pts/0 00:00:00 less 6294 pts/6 00:00:00 ps [rsimms@opus ~]$ [rsimms@opus ~]$ ps x PID TTY STAT TIME COMMAND 5368 ? S 0:00 sshd: rsimms@pts/0 5369 pts/0 Ss 0:00 -bash 6173 pts/0 S+ 0:00 man ps 6176 pts/0 S+ 0:00 sh -c (cd /usr/share/man && (echo ".ll 7.5i"; echo ".nr L 6177 pts/0 S+ 0:00 sh -c (cd /usr/share/man && (echo ".ll 7.5i"; echo ".nr L 6182 pts/0 S+ 0:00 /usr/bin/less -is 6203 ? S 0:00 sshd: rsimms@pts/6 6204 pts/6 Ss 0:00 -bash 6312 pts/6 R+ 0:00 ps x [rsimms@opus ~]$ -a show processes with a terminal x option shows full commands being run and states (most are asleep). I'm using two Putty sessions, in one session I have the man page open for ps, the other I'm issuing ps commands

  6. CIS 191 - Lesson 12 Process Information [rsimms@opus ~]$ cat /etc/passwd | grep Marcos valdemar:x:1200:103:Marcos Valdebenito:/home/cis90/valdemar:/bin/bash [rsimms@opus ~]$ ps -u 1200 PID TTY TIME CMD 5971 ? 00:00:00 sshd 5972 pts/5 00:00:00 bash [rsimms@opus ~]$ [rsimms@opus ~]$ ps -u dymesdia PID TTY TIME CMD 6418 ? 00:00:00 sshd 6419 pts/1 00:00:00 bash [rsimms@opus ~]$ [rsimms@opus ~]$ ps -u rsimms PID TTY TIME CMD 5368 ? 00:00:00 sshd 5369 pts/0 00:00:00 bash 6173 pts/0 00:00:00 man 6176 pts/0 00:00:00 sh 6177 pts/0 00:00:00 sh 6182 pts/0 00:00:00 less 6203 ? 00:00:00 sshd 6204 pts/6 00:00:00 bash 6510 pts/6 00:00:00 ps [rsimms@opus ~]$ Use the u option to look at processes owned by a specific user

  7. CIS 191 - Lesson 12 Process Information [rsimms@opus ~]$ cat /etc/passwd | grep Marcos valdemar:x:1200:103:Marcos Valdebenito:/home/cis90/valdemar:/bin/bash [rsimms@opus ~]$ ps -u 1200 PID TTY TIME CMD 5971 ? 00:00:00 sshd 5972 pts/5 00:00:00 bash [rsimms@opus ~]$ [rsimms@opus ~]$ ps -u dymesdia PID TTY TIME CMD 6418 ? 00:00:00 sshd 6419 pts/1 00:00:00 bash [rsimms@opus ~]$ [rsimms@opus ~]$ ps -u rsimms PID TTY TIME CMD 5368 ? 00:00:00 sshd 5369 pts/0 00:00:00 bash 6173 pts/0 00:00:00 man 6176 pts/0 00:00:00 sh 6177 pts/0 00:00:00 sh 6182 pts/0 00:00:00 less 6203 ? 00:00:00 sshd 6204 pts/6 00:00:00 bash 6510 pts/6 00:00:00 ps [rsimms@opus ~]$ Use the u option to look at processes owned by a specific user

  8. CIS 191 - Lesson 12 Process Information [rsimms@opus ~]$ ps -l F S UID PID PPID C PRI NI ADDR SZ WCHAN TTY TIME CMD 0 S 201 6204 6203 0 75 0 - 1165 wait pts/6 00:00:00 bash 0 R 201 6521 6204 0 77 0 - 1050 - pts/6 00:00:00 ps [rsimms@opus ~]$ Use –l for additional options

  9. CIS 191 - Lesson 12 Process Information [rsimms@opus ~]$ ps -ef UID PID PPID C STIME TTY TIME CMD root 1 0 0 Sep10 ? 00:00:05 init [3] root 2 1 0 Sep10 ? 00:00:00 [migration/0] root 3 1 0 Sep10 ? 00:00:00 [ksoftirqd/0] root 4 1 0 Sep10 ? 00:00:00 [watchdog/0] root 5 1 0 Sep10 ? 00:00:02 [migration/1] root 6 1 0 Sep10 ? 00:00:00 [ksoftirqd/1] root 7 1 0 Sep10 ? 00:00:00 [watchdog/1] root 8 1 0 Sep10 ? 00:00:00 [events/0] root 9 1 0 Sep10 ? 00:00:00 [events/1] root 10 1 0 Sep10 ? 00:00:00 [khelper] root 11 1 0 Sep10 ? 00:00:00 [kthread] root 15 11 0 Sep10 ? 00:00:00 [kblockd/0] root 16 11 0 Sep10 ? 00:00:00 [kblockd/1] root 17 11 0 Sep10 ? 00:00:00 [kacpid] root 109 11 0 Sep10 ? 00:00:00 [cqueue/0] root 110 11 0 Sep10 ? 00:00:00 [cqueue/1] root 113 11 0 Sep10 ? 00:00:00 [khubd] root 115 11 0 Sep10 ? 00:00:00 [kseriod] root 181 11 0 Sep10 ? 00:00:00 [pdflush] root 182 11 0 Sep10 ? 00:00:07 [pdflush] root 183 11 0 Sep10 ? 00:00:01 [kswapd0] root 184 11 0 Sep10 ? 00:00:00 [aio/0] root 185 11 0 Sep10 ? 00:00:00 [aio/1] root 341 11 0 Sep10 ? 00:00:00 [kpsmoused] root 371 11 0 Sep10 ? 00:00:00 [ata/0]

  10. CIS 191 - Lesson 12 Process Information root 372 11 0 Sep10 ? 00:00:00 [ata/1] root 373 11 0 Sep10 ? 00:00:00 [ata_aux] root 377 11 0 Sep10 ? 00:00:00 [scsi_eh_0] root 378 11 0 Sep10 ? 00:00:00 [scsi_eh_1] root 379 11 0 Sep10 ? 00:01:25 [kjournald] root 412 11 0 Sep10 ? 00:00:00 [kauditd] root 446 1 0 Sep10 ? 00:00:00 /sbin/udevd -d root 869 11 0 Sep10 ? 00:00:01 [kedac] root 1420 11 0 Sep10 ? 00:00:00 [kmpathd/0] root 1421 11 0 Sep10 ? 00:00:00 [kmpathd/1] root 2082 1 0 Sep10 ? 00:00:05 /usr/sbin/restorecond root 2098 1 0 Sep10 ? 00:00:11 auditd root 2100 2098 0 Sep10 ? 00:00:05 /sbin/audispd root 2120 1 0 Sep10 ? 00:00:23 syslogd -m 0 root 2123 1 0 Sep10 ? 00:00:00 klogd -x root 2160 1 0 Sep10 ? 00:00:20 mcstransd rpc 2183 1 0 Sep10 ? 00:00:00 portmap root 2201 1 0 Sep10 ? 00:01:18 /usr/bin/python -E /usr/sbin/setroub rpcuser 2227 1 0 Sep10 ? 00:00:00 rpc.statd root 2275 1 0 Sep10 ? 00:00:00 rpc.idmapd root 2345 1 0 Sep10 ? 00:00:00 /usr/bin/vmnet-bridge -d /var/run/vm root 2364 1 0 Sep10 ? 00:00:00 /usr/bin/vmnet-natd -d /var/run/vmne dbus 2383 1 0 Sep10 ? 00:00:15 dbus-daemon --system root 2434 1 0 Sep10 ? 00:00:51 pcscd root 2472 1 0 Sep10 ? 00:00:00 /usr/bin/hidd --server root 2493 1 0 Sep10 ? 00:00:02 automount

  11. CIS 191 - Lesson 12 Process Information root 2534 1 0 Sep10 ? 00:00:00 ./hpiod root 2539 1 0 Sep10 ? 00:00:00 python ./hpssd.py root 2556 1 0 Sep10 ? 00:00:00 cupsd root 2575 1 0 Sep10 ? 00:00:11 /usr/sbin/sshd root 2600 1 0 Sep10 ? 00:00:01 sendmail: accepting connections smmsp 2609 1 0 Sep10 ? 00:00:00 sendmail: Queue runner@01:00:00 for root 2626 1 0 Sep10 ? 00:00:00 crond xfs 2662 1 0 Sep10 ? 00:00:00 xfs -droppriv -daemon root 2693 1 0 Sep10 ? 00:00:00 /usr/sbin/atd root 2710 1 0 Sep10 ? 00:00:00 rhnsd --interval 240 root 2743 1 0 Sep10 ? 00:01:33 /usr/bin/python -tt /usr/sbin/yum-up root 2745 1 0 Sep10 ? 00:00:00 /usr/libexec/gam_server root 2749 1 0 Sep10 ? 00:00:00 /usr/bin/vmnet-netifup -d /var/run/v root 2758 1 0 Sep10 ? 00:00:00 /usr/bin/vmnet-netifup -d /var/run/v root 2768 1 0 Sep10 ? 00:00:00 /usr/bin/vmnet-netifup -d /var/run/v root 2827 1 0 Sep10 ? 00:00:00 /usr/bin/vmnet-dhcpd -cf /etc/vmware root 2858 1 0 Sep10 ? 00:00:00 /usr/bin/vmnet-dhcpd -cf /etc/vmware root 2859 1 0 Sep10 ? 00:00:00 /usr/bin/vmnet-dhcpd -cf /etc/vmware 68 2875 1 0 Sep10 ? 00:00:01 hald root 2876 2875 0 Sep10 ? 00:00:00 hald-runner 68 2883 2876 0 Sep10 ? 00:00:00 hald-addon-acpi: listening on acpid 68 2886 2876 0 Sep10 ? 00:00:00 hald-addon-keyboard: listening on /d 68 2890 2876 0 Sep10 ? 00:00:00 hald-addon-keyboard: listening on /d root 2898 2876 0 Sep10 ? 00:02:46 hald-addon-storage: polling /dev/hda root 2944 1 0 Sep10 ? 00:00:00 /usr/sbin/smartd -q never root 2949 1 0 Sep10 tty2 00:00:00 /sbin/mingetty tty2

  12. CIS 191 - Lesson 12 Process Information root 2950 1 0 Sep10 tty3 00:00:00 /sbin/mingetty tty3 root 5365 2575 0 08:19 ? 00:00:00 sshd: rsimms [priv] rsimms 5368 5365 0 08:19 ? 00:00:00 sshd: rsimms@pts/0 rsimms 5369 5368 0 08:19 pts/0 00:00:00 -bash root 5969 2575 0 10:14 ? 00:00:00 sshd: valdemar [priv] valdemar 5971 5969 0 10:14 ? 00:00:00 sshd: valdemar@pts/5 valdemar 5972 5971 0 10:14 pts/5 00:00:00 -bash rsimms 6173 5369 0 10:36 pts/0 00:00:00 man ps rsimms 6176 6173 0 10:36 pts/0 00:00:00 sh -c (cd /usr/share/man && (echo ". rsimms 6177 6176 0 10:36 pts/0 00:00:00 sh -c (cd /usr/share/man && (echo ". rsimms 6182 6177 0 10:36 pts/0 00:00:00 /usr/bin/less -is root 6200 2575 0 10:37 ? 00:00:00 sshd: rsimms [priv] rsimms 6203 6200 0 10:37 ? 00:00:00 sshd: rsimms@pts/6 rsimms 6204 6203 0 10:37 pts/6 00:00:00 -bash root 6408 2575 0 11:07 ? 00:00:00 sshd: dymesdia [priv] dymesdia 6418 6408 0 11:08 ? 00:00:00 sshd: dymesdia@pts/1 dymesdia 6419 6418 0 11:08 pts/1 00:00:00 -bash rsimms 6524 6204 0 11:15 pts/6 00:00:00 ps -ef lyonsrob 12891 1 0 Oct01 ? 00:00:00 SCREEN lyonsrob 12892 12891 0 Oct01 pts/3 00:00:00 /bin/bash root 29218 1 0 Oct15 tty1 00:00:00 /sbin/mingetty tty1 [rsimms@opus ~]$

  13. CIS 191 - Lesson 12 Signals

  14. CIS 191 - Lesson 12 Signals • Signals are asynchronous messages sent to processes • They can result in one of three courses of action: • be ignored, • default action (die) • execute some predefined function. • Signals are sent: • Using the kill command: $ kill -# PID • Where # is the signal number and PID is the process id. • if no number is specified, SIGTERM is sent. • Using special keystrokes • limited to just a few signals Use kill –l to see all signals

  15. CIS 191 - Lesson 12 Signals Use kill –l to see all of them /home/cis90/roddyduk $ kill -l 1) SIGHUP 2) SIGINT 3) SIGQUIT 4) SIGILL 5) SIGTRAP 6) SIGABRT 7) SIGBUS 8) SIGFPE 9) SIGKILL 10) SIGUSR1 11) SIGSEGV 12) SIGUSR2 13) SIGPIPE 14) SIGALRM 15) SIGTERM 16) SIGSTKFLT 17) SIGCHLD 18) SIGCONT 19) SIGSTOP 20) SIGTSTP 21) SIGTTIN 22) SIGTTOU 23) SIGURG 24) SIGXCPU 25) SIGXFSZ 26) SIGVTALRM 27) SIGPROF 28) SIGWINCH 29) SIGIO 30) SIGPWR 31) SIGSYS 34) SIGRTMIN 35) SIGRTMIN+1 36) SIGRTMIN+2 37) SIGRTMIN+3 38) SIGRTMIN+4 39) SIGRTMIN+5 40) SIGRTMIN+6 41) SIGRTMIN+7 42) SIGRTMIN+8 43) SIGRTMIN+9 44) SIGRTMIN+10 45) SIGRTMIN+11 46) SIGRTMIN+12 47) SIGRTMIN+13 48) SIGRTMIN+14 49) SIGRTMIN+15 50) SIGRTMAX-14 51) SIGRTMAX-13 52) SIGRTMAX-12 53) SIGRTMAX-11 54) SIGRTMAX-10 55) SIGRTMAX-9 56) SIGRTMAX-8 57) SIGRTMAX-7 58) SIGRTMAX-6 59) SIGRTMAX-5 60) SIGRTMAX-4 61) SIGRTMAX-3 62) SIGRTMAX-2 63) SIGRTMAX-1 64) SIGRTMAX /home/cis90/roddyduk $

  16. CIS 191 - Lesson 12 Signals Special keystrokes /home/cis90/roddyduk $ stty -a speed 38400 baud; rows 26; columns 78; line = 0; intr = ^C; quit = ^\; erase = ^?; kill = ^U; eof = ^D; eol = <undef>; eol2 = <undef>; swtch = <undef>; start = ^Q; stop = ^S; susp = ^F; rprnt = ^R; werase = ^W; lnext = ^V; flush = ^O; min = 1; time = 0; [rsimms@opus ~]$ stty -a speed 38400 baud; rows 39; columns 84; line = 0; intr = ^C; quit = ^\; erase = ^?; kill = ^U; eof = ^D; eol = <undef>; eol2 = <undef>; swtch = <undef>; start = ^Q; stop = ^S; susp = ^Z; rprnt = ^R; werase = ^W; lnext = ^V; flush = ^O; min = 1; time = 0; use stty –a to see special keystrokes

  17. CIS 191 - Lesson 12 System Monitoring uptime [root@benji ~]# uptime 09:30:41 up 3 days, 19:27, 5 users, load average: 0.00, 0.00, 0.00 [root@benji ~]# Uptime shows how long the system has been running

  18. CIS 191 - Lesson 12 System Monitoring top Use top to find CPU hogs and memory leaks

  19. CIS 191 - Lesson 12 System Monitoring top for the past 1, 5 and 15 minutes PR = priority NI = nice values VIRT=Virtual memory used RES=Physical memory used SHR=Shared memory used Use top to find CPU hogs and memory leaks

  20. CIS 191 - Lesson 12 System Monitoring top for the past 1, 5 and 15 minutes PR = priority NI = nice values VIRT=Virtual memory used RES=Physical memory used SHR=Shared memory used Use top to find CPU hogs and memory leaks

  21. CIS 191 - Lesson 12 System Monitoring top binary calculator Running Jim's cpu.sh script (uses binary calculator)

  22. CIS 191 - Lesson 12 System Monitoring top Running Jim's disk.sh script (lots of find commands)

  23. CIS 191 - Lesson 12 System Monitoring top Running Jim's sleep script

  24. CIS 191 - Lesson 12 System Monitoring vmstat [root@benji ~]# vmstat procs -----------memory---------- ---swap-- -----io---- --system-- -----cpu------ r b swpd free buff cache si so bi bo in cs us sy id wast 0 0 88 7032 110092 195420 0 0 11 11 71 72 0 0 99 0 0 IO bi: Blocks received from a block device (blocks/s). bo: Blocks sent to a block device (blocks/s). System in: The number of interrupts per second, including the clock. cs: The number of context switches per second. CPU These are percentages of total CPU time. us: Time spent running non-kernel code. (user time, including nice time) sy: Time spent running kernel code. (system time) id: Time spent idle. Prior to Linux 2.5.41, this includes IO-wait time. wa: Time spent waiting for IO. Prior to Linux 2.5.41, included in idle. st: Time stolen from a virtual machine. Prior to Linux 2.6.11, unknown. Procs r: The number of processes waiting for run time. b: The number of processes in uninterruptible sleep. Memory swpd: the amount of virtual memory used. free: the amount of idle memory. buff: the amount of memory used as buffers. cache: the amount of memory used as cache. inact: the amount of inactive memory. (-a option) active: the amount of active memory. (-a option) Swap si: Amount of memory swapped in from disk (/s). so: Amount of memory swapped to disk (/s).

  25. CIS 191 - Lesson 12 scheduling

  26. CIS 191 - Lesson 12 System Monitoring Scheduling Jobs • at • cron • anacron

  27. CIS 191 - Lesson 12 at

  28. CIS 191 - Lesson 12 at command Use the at command to schedule a command or script to run in the future • So that the multiprocessing CPU on a UNIX system does not get overloaded, some processes need to be run during low peak hours such as early in the morning or later in the day. • The at command is for this purpose. • The at command reads its stdin for a list of commands to run, and begins running them at the time of day specified as the first argument: • $ at 10:30pm < batch_file • $ at 11:59pmat> cat files.outbigshell > lab08at> cp lab08 /home/rsimms/cis90/$LOGNAME       at>Ctrl-D$ Note: the Ctrl-d must be entered as the first character on the last line.

  29. CIS 191 - Lesson 12 Load Balancing This job makes a backup of myscript and sends an email when finished /home/cis90/roddyduk $ cat job1 cp bin/myscript bin/myscript.bak echo "Job 1 - finished, myscript has been backed up" | mail -s "Job 1" roddyduk /home/cis90/roddyduk $ at now + 5 minutes < job1 job 24 at 2008-11-12 12:14 /home/cis90/roddyduk $ at now + 2 hours < job1 job 25 at 2008-11-12 14:09 /home/cis90/roddyduk $ at teatime < job1 job 26 at 2008-11-12 16:00 /home/cis90/roddyduk $ at now + 1 week < job1 job 27 at 2008-11-19 12:10 /home/cis90/roddyduk $ at 3:00 12/12/2008 < job1 job 28 at 2008-12-12 03:00 /home/cis90/roddyduk $ jobs /home/cis90/roddyduk $ atq 25 2008-11-12 14:09 a roddyduk 28 2008-12-12 03:00 a roddyduk 27 2008-11-19 12:10 a roddyduk 26 2008-11-12 16:00 a roddyduk 24 2008-11-12 12:14 a roddyduk /home/cis90/roddyduk $ Several ways to specify a future time to run Use the atq command to show queued jobs

  30. CIS 191 - Lesson 12 Load Balancing The jobs command lists processes running or suspended in the background. The atq command lists jobs queued to run in the futures that were scheduled by at command /home/cis90/roddyduk $ jobs /home/cis90/roddyduk $ atq 25 2008-11-12 14:09 a roddyduk 28 2008-12-12 03:00 a roddyduk 27 2008-11-19 12:10 a roddyduk 26 2008-11-12 16:00 a roddyduk 24 2008-11-12 12:14 a roddyduk /home/cis90/roddyduk $ atrm 24 /home/cis90/roddyduk $ atq 25 2008-11-12 14:09 a roddyduk 28 2008-12-12 03:00 a roddyduk 27 2008-11-19 12:10 a roddyduk 26 2008-11-12 16:00 a roddyduk /home/cis90/roddyduk $ The atrm command is used to remove jobs from the queue

  31. CIS 191 - Lesson 12 cron

  32. CIS 191 - Lesson 12 System Monitoring Scheduling Batch (cron) Jobs • cron - Scheduling Program that executes tasks at a given time • crontab - a program that submits tasks to the cron daemon • crontab filename - registers your cron file • crontab -l - displays your current cron file • crontab -r - removes your current cron file • crontab -u user - sets a cron job for another user • Crontab service can be denied or allowed on a per/user basis • crond cron daemon examines crontab files and at command files.

  33. CIS 191 - Lesson 12 cron crond daemon lives in /usr/sbin [root@benji ~]# type crond crond is /usr/sbin/crond [root@benji ~]# ps -ef | grep crond root 2236 1 0 Nov26 ? 00:00:02 crond root 16329 14952 0 08:53 pts/2 00:00:00 grep crond [root@benji ~]# service crond stop Stopping crond: [ OK ] [root@benji ~]# service crond start Starting crond: [ OK ] [root@benji ~]# chkconfig --list crond crond 0:off 1:off 2:on 3:on 4:on 5:on 6:off [root@benji ~]# chkconfig --level 3 crond off [root@benji ~]# chkconfig --list crond crond 0:off 1:off 2:on 3:off 4:on 5:on 6:off [root@benji ~]# chkconfig --level 3 crond on [root@benji ~]# chkconfig --list crond crond 0:off 1:off 2:on 3:on 4:on 5:on 6:off crond's parent is init service command can be used to stop and start (Red Hat family) checkcfg command can be used to configure startup by run level

  34. CIS 191 - Lesson 12 System Monitoring Scheduling Batch (cron) Jobs • Two cron options: • "System" cron jobs • Uses /etc/crontab (has additional user field) • No need to edit cron files just drop new jobs in: • /etc/cron.daily/ • /etc/cron.weekly/ • /etc/cron.monthly/ • Fortified with anacron • "User" cron jobs • Uses cron files kept in /var/spool/cron • Use crontab commands to create, view, and remove cron files • One cron file per user (multiple entries for multiple jobs)

  35. CIS 191 - Lesson 12 System cron jobs [root@benji ~]# cat /etc/crontab SHELL=/bin/bash PATH=/sbin:/bin:/usr/sbin:/usr/bin MAILTO=root HOME=/ # run-parts 01 * * * * root run-parts /etc/cron.hourly 02 4 * * * root run-parts /etc/cron.daily 22 4 * * 0 root run-parts /etc/cron.weekly 42 4 1 * * root run-parts /etc/cron.monthly [root@benji ~]# spam assassin cron file Has additional user field [root@benji ~]# ls /etc/cron* /etc/cron.deny /etc/crontab /etc/cron.d: sa-update /etc/cron.daily: 0anacron cups makewhatis.cron prelink tmpwatch 0logwatch logrotate mlocate.cron rpm /etc/cron.hourly: /etc/cron.monthly: 0anacron /etc/cron.weekly: 0anacron makewhatis.cron [root@benji ~]# Note: 0anacron is the first job to run in each cron directory. anacron complements cron by handling jobs that were scheduled to run when the system was down.

  36. CIS 191 - Lesson 12 Creating user cron jobs Option 1 [root@benji ~]# crontab –e crontab: installing new crontab [root@benji ~]# ls cron* crontest-1 crontest-2 [root@benji ~]# cat cron* Every minute: Sat Nov 29 08:26:01 PST 2008 Every minute: Sat Nov 29 08:27:01 PST 2008 Every minute: Sat Nov 29 08:28:01 PST 2008 Every minute: Sat Nov 29 08:29:01 PST 2008 Every 2 minutes: Sat Nov 29 08:26:01 PST 2008 Every 2 minutes: Sat Nov 29 08:28:01 PST 2008 [root@benji ~]# Create a cron job with the crontab –e command which uses vi

  37. CIS 191 - Lesson 12 Creating user cron jobs Option 2 [root@benji ~]# vi cron [root@benji ~]# cat cron 00 03 * * 0 /sbin/dump 0uf /backup/level0/backup-L0-`date +\%Y-\%d-\%m`.dmp /home 00 01 * * 1-6 /sbin/dump 1uf /backup/level1/backup-L1-`date +\%Y-\%d-\%m`.dmp /home [root@benji ~]# crontab cron [root@benji ~]# Create a cron job with vi then register it

  38. CIS 191 - Lesson 12 User cron jobs Note: No user field like in /etc/crontab Min Hr Day Month Weekday Job 30 08 1 3,6,9,12 * /root/bin/script1 At 8:30 AM, on the first day of every quarter

  39. CIS 191 - Lesson 12 User cron jobs Min Hr Day Month Weekday Job 30 10 * * 6 /root/bin/script1 At 10:30 AM every Saturday

  40. CIS 191 - Lesson 12 User cron jobs Min Hr Day Month Weekday Job 30 10 * * 1-5 /root/bin/script1 At 10:30 AM week days Monday through Friday

  41. CIS 191 - Lesson 12 User cron jobs Min Hr Day Month Weekday Job 0,10,20,30,40,50 * 5 5 * /root/bin/script1 script1 runs every 10 minutes on May 5th

  42. CIS 191 - Lesson 12 User cron jobs Min Hr Day Month Weekday Job */5 * * * * /root/bin/script1 script1 runs every 5 minutes

  43. CIS 191 - Lesson 12 User cron jobs Min Hr Day Month Weekday Job */10 * * * * /root/bin/script1 script1 runs every 10 minutes

  44. CIS 191 - Lesson 12 User cron jobs Min Hr Day Month Weekday Job 30 07 1 4 * /root/bin/script1 31,32,33 07 1 4 * /root/bin/script2 On April 1st, script1 is run at 7:30AM followed by script2 running at 7:31AM, 7:32AM and 7:33AM

  45. CIS 191 - Lesson 12 User cron jobs Min Hr Day Month Weekday Job Everyday at 10 minutes past midnight 10 0 * * * /root/bin/script >> /root/script.log 2>&1 00 18 */2 * * /root/bin/script >> /root/script.log 2>&1 0 8 * * 1-5 /root/bin/script >> /root/script.log 2>&1 0 12 4 7 * /root/bin/script >> /root/script.log 2>&1 Every other day at 6:00 PM Weekdays at 8:00 AM Noon on the 4th of July

  46. CIS 191 - Lesson 12 User cron jobs [root@benji ~]# cat crontest Sat Nov 29 10:54:01 PST 2008 To file Sat Nov 29 10:56:01 PST 2008 To file Where does job output go ????????????? */2 * * * * echo `date` "To file" >> /root/crontest */2 * * * * echo `date` "To email" stdout and stderr get emailed if not redirected [root@benji ~]# mail Mail version 8.1 6/6/93. Type ? for help. "/var/spool/mail/root": 2 messages 2 unread >U 1 root@benji.localdoma Sat Nov 29 10:54 24/894 "Cron <root@benji> ech" U 2 root@benji.localdoma Sat Nov 29 10:56 24/894 "Cron <root@benji> ech" & 1 Message 1: From root@benji.localdomain Sat Nov 29 10:54:01 2008 Date: Sat, 29 Nov 2008 10:54:01 -0800 From: root@benji.localdomain (Cron Daemon) To: root@benji.localdomain Subject: Cron <root@benji> echo `date` "To email" Content-Type: text/plain; charset=UTF-8 Auto-Submitted: auto-generated X-Cron-Env: <SHELL=/bin/sh> X-Cron-Env: <HOME=/root> X-Cron-Env: <PATH=/usr/bin:/bin> X-Cron-Env: <LOGNAME=root> X-Cron-Env: <USER=root> Sat Nov 29 10:54:01 PST 2008 To email

  47. CIS 191 - Lesson 12 User cron jobs User cron jobs are stored in /var/spool/cron/ by user name [root@benji ~]# ls -l /var/spool/cron total 2 -rw------- 1 root root 127 Nov 29 08:29 root [root@benji ~]# cat /var/spool/cron/root * * * * * echo "Every minute: " `date` >> /root/crontest-1 */2 * * * * echo "Every 2 minutes: " `date` >> /root/crontest-2 [root@benji ~]# [root@benji ~]# crontab -l * * * * * echo "Every minute: " `date` >> /root/crontest-1 */2 * * * * echo "Every 2 minutes: " `date` >> /root/crontest-2 [root@benji ~]# crontab –l lists the user's cron jobs

  48. CIS 191 - Lesson 12 User cron jobs crontab –r will delete a user' s cron configuration file [root@benji ~]# crontab -l * * * * * echo "Every minute: " `date` >> /root/crontest-1 */2 * * * * echo "Every 2 minutes: " `date` >> /root/crontest-2 [root@benji ~]# crontab -r [root@benji ~]# crontab -l no crontab for root [root@benji ~]#

  49. CIS 191 - Lesson 12 User cron jobs Linux lets anyone run cron jobs. You can use /etc/cron.allow and /etc/cron.deny to manage as necessary. Add users, one per line. [root@benji ~]# echo gimli >> /etc/cron.deny [root@benji ~]# su - gimli : crontab -e You (gimli) are not allowed to use this program (crontab) See crontab(1) for more information : exit logout [root@benji ~]# If there is a conflict, the most restrictive will apply

  50. CIS 191 - Lesson 12 User cron jobs Backup example Create a cron file as root to perform a backup of the /home file system. Do a full level 0 backup, followed by 3 level 1 backups, followed by 3 level 2 backups. escapes needed [root@benji ~]# mkdir -p /backup/level0 /backup/level1 /backup/level2 [root@benji ~]# vi cron [root@benji ~]# cat cron 30 7 * * * /sbin/dump 0uf /backup/level0/backup-L0-`date +\%Y-\%d-\%m`.dmp /home 31-33 7 * * * /sbin/dump 1uf /backup/level1/backup-L1-`date +\%Y-\%d-\%m`.dmp /home 34-36 7 * * * /sbin/dump 2uf /backup/level2/backup-L2-`date +\%Y-\%d-\%m`.dmp /home [root@benji ~]# crontab cron [root@benji ~]# crontab -l 30 7 * * * /sbin/dump 0uf /backup/level0/backup-L0-`date +\%Y-\%d-\%m`.dmp /home 31-33 7 * * * /sbin/dump 1uf /backup/level1/backup-L1-`date +\%Y-\%d-\%m`.dmp /home 34-36 7 * * * /sbin/dump 2uf /backup/level2/backup-L2-`date +\%Y-\%d-\%m`.dmp /home [root@benji ~]# Note, for demonstration purposes we are doing the backups every minute rather than everyday.

More Related