Daily Management - Level one

•/etc/passwd Contains the basics of a user

•/etc/security/.profile Providing the user profile

•/etc/security/limits Contains all the ulimits, or users' system resource limitations

•/etc/security/passwd Contains the AIX user's password information

•/etc/security/user Contains the most important settings

•/usr/lib/security/mkuser.default Contains values used when creating user through mkuser

# getconf LOGIN_NAME_MAX To verify the setting in AIX 5.3 and later

# lsattr -El sys0 To verify the setting in AIX 5.3 and later

# chdev -l sys0 -a max_logname=129 To change the value of sys0

# mkuser xander To create a user with default settings

# finger xander Gives the short information of user

# chuser core=1048576 xander To change the User attribute

# chsh xander To change the user login shell

# chfn xander To change GECOS information

# lsuser -f xander List the user in stanza format

# passwd xander To set or change password of user

# passwd -f xander To change user GECOS using passwd command

# passwd -s xander To change the user SHELL using passwd

# rmuser xander Remove the user

# rmuser –p xander To remove fully user information

•/etc/group Contains the basics of a group

•/etc/security/group Contains extended attributes to the specified group

# mkgroup atctest To create a group

# mkgroup -a atcadmin To create an admin group

# mkgroup adms=xander xangroup To create a group and add Xander as the administrator of the group

# chgroup id=204 users=xander,atc,amdc xangroup Change the group's GID and add users

# chgrpmem Another way to modify a group's members is with chgrpmem

# chgrpmem xangroup List the group information

# chgrpmem -m - atc xangroup Remove a user from a group

# lsgroup xangroup List the info of group

# lsgroup -f xangroup List info of group in stanza fromat

# rmgroup atctest Remove the group

•/etc/security/environ Contains the environment attributes for users

•/etc/security/lastlog Contains the last login attributes for users

•/usr/lib/security/mkuser.sys Customizes new user accounts

•/etc/security/login.cfg Contains system default login parameters

•/etc/utmp Contains a record of users logged into the system

•/var/adm/wtmp Contains connect-time accounting records

•/etc/security/failedlogin Records all failed login attempts

•/etc/motd Contains the message to be displayed every time user login

•/etc/environment Specifies the basic environment for all processes.

•/etc/profile Specifies additional environment settings for all users.

•$HOME/.profile Specifies environment settings for a specific user.

# ps -ef To display all processes

# ps -f -l -ujim To list processes owned by specific users

# ps -M To list all the 64-bit processes

# kill 1095 To stop a given process

# kill -kill 2098 1569 To stop several processes that ignore the default signal

# kill -kill 0 To stop all of your processes and log yourself off

# kill -9 -1 To stop all processes that you own

# fuser -u /etc/filesystems List a process numbers and user login names of processes

# fuser -k -x -u -c /dev/hd1 To terminate all of the processes using a given file system

# fuser -kxuc /home To terminate all of the processes using a given file system

# fuser -d /usr To list all processes that are using a file that has been deleted from a given file system

# fuser -xc /tmp List open references within a specified file system

# find /home -type d -exec fuser -u {} \; Process is using a directory within the file system as its current working directory

# topas -i5 -n0 -p10 To view the top 10 processes

The svmon command captures and analyzes a snapshot of virtual memory

The svmon command creates nine types of reports

# svmon -G Global Report

# svmon -U User Report

# svmon -C Command Report

# svmon -W Workload Management Class Report

# svmon -T Workload Management Tier Report

# svmon -P Process Report

# svmon -S Segment Report

# svmon -D Detailed Report

# svmon -F Framed Report

# aclget status To display the access control information of status file

# aclput -i acldefs status To set the access control information of status from acldefs

# aclget plans | aclput status To set the access control information of status from plans

# acledit plans To edit the access control information of the plans

#chown -R john:build /tmp/src To change the owner & group of all files in the directory

# chmod 644 text To use the absolute mode

#chgrp -R staff proposals Change the group ownership of the directory named proposals of dir stuff

# at -f filename -t CCYYMMDDhhmmSS Increment Submit a job to be run at a later time

# at now -f appl/program > /dev/null 2>&1 To start at job now

# atq List the at jobs

# at -r root.1134169200.a Remove the at job

# ls /var/spool/cron/atjobs Location of at jobs

# ls -l /var/spool/cron/crontabs Location of cron jobs

# crontab -l List the all cron jobs

# crontab -e To edit crontab file

# crontab -v username Lists the status of the user's cron jobs

# crontab -r Remove the crontab file

# crontab ~deploy/deploy.schedule Runs the crontab file under user deploy

•/var/adm/cron/log The cron daemon logs file

•/var/adm/cron/cron.deny Deny cron access to user for cron schedular

•/var/adm/cron/cron.allow Allow cron access to user for cron schedular

•/var/adm/cron/at.allow Allow cron access to user for at schedular

•/var/adm/cron/at.deny Deny cron access to user for at schedular

# telinit Directs the actions of the init process

# telinit M Goes into the maintainance mode

# telinit q Tell the init command to reprocess the /etc/inittab

Normally, you do not need to restart srcmstr. If the srcmstr daemon terminates abnormally, the respawn action specified in the /etc/inittab restarts the srcmstr daemon.

A command is a request to perform an operation or run a program. A program or command that is actually running on the computer is referred to as a process.

The common types of processes are:

Foreground and background processes

Processes that require a user to start them or to interact with them are called foreground processes. Processes that are run independently of a user are referred to as background processes. Programs and commands run as foreground processes by default.

Daemon processes

Daemons are processes that run unattended. They are constantly in the background and are available at all times. Daemons are usually started when the system starts, and they run until the system stops. A daemon process typically performs system services and is available at all times to more than one task or user. Daemon processes are started by the root user or root shell and can be stopped only by the root user. For example, the qdaemon process provides access to system resources such as printers. Another common daemon is the sendmail daemon.

Zombie processes

A zombie process is a dead process that is no longer executing but is still recognized in the process table (in other words, it has a PID number). It has no other system space allocated to it. Zombie processes have been killed or have exited and continue to exist in the process table until the parent process dies or the system is shut down and restarted. Zombie processes display as <defunct> when listed by the ps command.

Ctrl-C To intrrupt the process

Ctrl-Z To stop process

# fg 589934 To bring the process in to the foreground

# find / -type f > dir.paths & Run the find command in the background

# nohup find / -type f & To run the find command and leave it running after you log off in Bg

0 Represents standard input (stdin) <

1 Represents standard output (stdout) > or >> (append)

2 Represents standard error (stderr) 2> or 2>> (append)

2>&1 Redirects stderr to stdout.

1>&2 Redirects stdout to stderr

Performance Monitoring

# nice -10 foo Add 10 to current nice value (Lower Priority)

# nice -n 10 foo Add 10 to current nice value (Lower Priority)

# nice - -10 foo Subtract 10 from current value (Higher Priority)

# nice -n -10 foo Subtract 10 from current value (Higher Priority)

# renice -10 –p 563 Add 10 to default nice value (Lower Priority)

# renice –n 10 –p 563 Add 10 to current nice value (Lower Priority)

# renice - -10 –p 563 Subtract 10 from default nice value (Higher Priority)

# renice –n -10 –p 563 Subtract 10 from current nice value (Higher Priority)

# ps –ekl Long listing of kernel processes with priority

# ps –L 483445 –l It list the child the processes of parent process

# ps –kmo THREAD –p 16396 It list the threads of particular processes

# schedo To change the CPU usage priority decay rate

Context Switch : A context switch is when one thread is taken off a CPU and another thread is despatched onto the same CPU.

User Mode : User mode is when thread is executing its own application code or shared library code. Time spent in user mode is reflected as %user time in output of commands such as vmstat, topas, iostat, sar.

System Mode : System Mode is when the CPU is executing code in the kernel. CPU time spent in kernel mode is reflected as system time in output of vmstat, topas, iostat, sar commands. Context switch time, system calls, device interrupts, NFS I/O, and anything else in the kernel is considered as system time.

# time It show the elapsed time in system and user mode

# vmstat 5 3

# vmstat -f To display fork statistics

# vmstat -s To display count of various events

# sar –P ALL 5 1 All CPU related usage

# sar –q 5 3 Queue details

# ps aux Locating the dominant processes

# tprof –x sleep 60 Reports processor usages

# lparstat 2 3 System wide CPU report

# sar –P ALL 2 2 Viewing CPU statistic with SMT

# sar -d 1 2 Disk I/O statistic

# smtctl To check SMT is enabled or not

# smtctl –m on –w now Tern on SMT immediately

# smtctl –m on –w boot Tern on SMT at next reboot

# bindprocessor –q To check logical CPU

# iostat I/O device statistics

# iostat -d hdisk2 2 Continuous disk report

# netstat network statistic

# netstat -rn Network routing table

# netstat -rs Network routing statistic

CPU bound A system is said to be CPU-bound if the total system (sy) and user (us) CPU usage is approaching 100 percent. This would imply that idle time and wait time for CPU are approaching zero.

Memory bound A system is memory-bound if some virtual memory is forced out to disk, meaning the system is waiting on a relatively slow disk instead of relatively fast RAM. This is indicated by a non-zero value in the page-in (pi) and page-out (po) values.

Paging rate is the average number of page-ins and page-outs per CPU cycle.

Idle time calculation:

Total CPU Idle Time % = wait % + Idle Time %

Ex:

Average CPU Idle Time percentage = ((99+1) + (97+2) + (95+4) + (99+1))/4 = 99.5%