AIX System Engineer Guide

Audit Files in AIX

/var/adm/sulog
/var/adm/lastlog
/etc/inetd.conf
/etc/passwd
/etc/security/user
/etc/security/passwd
/etc/security/last
/etc/security/audit/config
ls –al/var/spool/cron/crontabs
Critical files Permissions
                  (1) ls –lLd /etc
                  (2) ls –lLd /etc/security
                  (3) ls –lLd /bin
                  (4) ls –lLd /usr
                  (5) ls –lLd /var
                  (6) ls –lLd /sbin

cut -d: -f6 /etc/passwd | sort -u | xargs -I {} -t ls -ld {}/.netrc
cut -d: -f6 /etc/passwd | sort -u | xargs -I {} -t ls -ld {}/.rhosts

/etc/hosts.equiv
/etc/ftpusers
instfix –iv

Service Process

To clean Sendmail command queue .

/usr/lib/smdemon.cleanu

To stop tcp/ip daemon

/etc/tcp.clean

To Start NFS Services:

mknfs -N

If the /etc/exports file does not exist, the nfsd and the rpc.mountd daemons will not be started. You can create an empty /etc/exports file by running the command touch /etc/exports. This will allow the nfsd and the rpc.mountd daemons to start, although no file systems will be exported.

Inetd configuration file
/etc/inetd.conf

/etc/services - information about services, such as port number

Starting and stopping a process:
refresh -p <pid>
refresh -s <subsystem name>

Changing the inetd configuration

    Files
        /etc/inetd.conf
        /etc/services
    Using smit - daemon is recycled automatically upon exit
    Using vi
        restart the inetd daemon so that the new configuration is read:
        refresh -s inetd
    Using chservices to edit /etc/services
        chservices -c --> changes entries
        chservices -a --> adds entries
        chservices -d --> deactivates entries

Boot Process

During Boot Process, the system will test hardware, loads and runs the operating system, and configures devices.

To boot the operating system, a boot image is loaded and access to / and /usr filesystem is required.

Cold Boot : System is started by turning on the power switch

Warm Boot: System is restarted by shutdown or reboot command.

Events occurs on system before it is ready for use.

1. ROS (Read Only Storage) Kernel init phase. (Problems with the motherboard are checked. It searches for bootlist and boot image is read into memory and system initialization starts.)

2. Base device configuration phase. ( All the devices are configured with cfgmgr )

3. System Boot phase.(all the lv's are varied on ,paging is started and inittab is processed)

RS6000 uses sound and graphics to show different phases of the boot process. As soon as you power on the system, an audio beep is produced when the processor is found to be active, the PowerPC logo is shown (or text is presented) when the system memory checking is completed, and device logos are shown for all devices that have a valid address. At the end of the device logo display, if the system ROS is not damaged, an audio beep is again produced.

To clear the boot record
# mkboot -c -d /dev/hdisk

Korn Shell Tips

1. To erase ^?^?^?    when typing backspace.

      # stty erase ^?

2. To activate esc key functions. To navigate the command line like a vi session

       #   set -o vi

While Loop

Execute controlled while loop .

Shell Tips and Tricks

Command Line Short cuts:

1. You can edit previous command/one liner in vi editor simply by pressing "v". This takes the shell into vi mode.

Eg:      # for i in 0 1
            > do
            > lspv | grep hdisk$i
            > done

Press Esc+k

Press v

Update the Script, Added 2 3 and press :wq! < To save and exit>

Now the command/Oneliner is executed .

To Keep Processor Busy

Q: How to keep processor busy.

A: yes > /dev/null

Above Command will put load on Single Processor Thread.
To Keep Mutliple Processor Threads Busy . Run the above command multiple times.

KDB Commands on AIX.

Perfpmr for AIX Performance Issue

1. Download PERFPMR from ibm site <Binary Format>

2. Upload the perfpmr to server in /tmp.

3. Create Directory in /tmp. eg : perf71. untar the perfpmr.

# cd /tmp

# uncompress perf71.tar.Z

# cd perf71 ; tar -xvf /tmp/perf71.tar

# cd /tmp/perf71 ; ls -ltr

(or)

# mkdir /tmp/perf71

# cd /tmp/perf71

   # zcat /tmp/perf71.tar.Z | tar -xvf -

4. Create another directory in /tmp to collect perfpmr logs. Eg: perfpmrdata

   # mkdir /tmp/perfdata

   # cd /tmp/perfdata

5. Execute perfpmr.sh from perfdata directory. Default it would be running for 600 Seconds (i.e, 10 Mins)

For Completing of below command it would take 18 to 20 Mins in real world.

# cd /tmp/perfdata

# /tmp/perf71/perfpmr.sh (or) # /tmp/perf71/perfpmr.sh 600

6. Send perfpmr logs collected in /tmp/perfdata to IBM for analysis.

      # cd /tmp/perfdata

      # cd ..

      # pax -xpax -vw perfdata | gzip -c > pmr#.pax.gz

More Details can be found in /tmp/perf71/README file.

AIX Server Reboot Checklist

1. Check the rootvg mirrored properly or not.
   # lsvg -l rootvg

2. Check bootlv is assigned Properly or not.

3. Check the bootlist and re-run the boot image.
          # bootlist -m normal -o
# bootlist -m normal <hdisk#> <hdisk#>
          # bosboot -ad </dev/hdisk#>   (or) # bosboot -a

4. Check Server Configuration and take backup of Server Configuration.

5. Reboot server.
   # shutdown -Fr