Basic Questions in AIX

Basic Questions in AIX
1 How will u check OS LEVEL?
#oslevel #uname -vr

2 Any idea about ML, &How do u install?
Yes.Maintainance level .Now a days it is called as Technology level….
a) Get it from IBM .It is a free ware .it will be in tar.gz format.
(For example 5100007.tar.gz)
b) Copy it to /usr/sys/inst.images directory.
c) Unzip and Untar
(# gun zip 5100007.tar.gz | tar -xvf --)
d) Run inutoc command.
(#inutoc /usr/sys/inst.images)
e) Take a rootvg backup. (Don’t forget)
( #mksysb - ief /dev/rmt0 )
f) Install the bos.rte.install fileset
(# installp -acXd /usr/sys/inst.images/bos.rte.install
Or #smitty update_all )
g)Restart the server.
( #shutdown –Fr )
h) Check the installed ML.
( #oslevel -r )

3 How do you install APAR?
#instfix -k

4 How will u check APAR installed or not?
#instfix -ik

5 How will u create a User?
#mkuser -a

6 How will u lock a User?
#chuser account_locked=true user name.
#chuser expires=current time user name

7 How do u create a VG?
#lspv (to check for pv availability)
#mkvg –y -s (1mb - 128 gb) pv name

8 How do u change size of file systems?
#chfs -a size=new size filesystem name
[ before that check for free space
#lsvg vgname
If space is not there check for free pvs by
#lspv (we can use the pvs listed without assigned to any vgs)
#extendvg
If no free pv means add a new pv if it is a hot pluggable server and run
#cfgmgr
Then extend it to vg and increase the size.]

9 How do u create a file system?
#crfs -v jfs/jfs2 -a size = value -m /mount point
And check whether it is created or not by using
#lsfs /mount point

10 How will u check free PVs are available?
#lspv

11 How do u install a file set?
( 2 way Committ or Apply mode )
#installp -a
#installp -ac
#smitty installp

12 How will u check a file set installed or not?
#lslpp –l

13 How do u start services?
#startsrc -g group name (eg. Nfs,tcpip or yp)
#startsrc -s service name (eg inetd,sendmail,ypserv)
#startsrc -t subserver name (eg telnetd,ftpd)

14 How do u check whether Samba services are running or not?
#lssrc -s smbd
#ps -ef | grep -ip smbd

15 How do u take a root vg backup?
#mksysb -if /dev/rmt0

16 How do u take backup of files?
#tar -cvf /dev/rmt0

17 How do u take backup of file systems?
#backup -f /dev/rmt0

18 How will u restore a file from already take backup using backup?
#restore -xvqf /dev/rmt0

19 How will u append a file to a previous archive take by Tar?
#tar -rvf /dev/rmt0

22 How will u check a Tape is Mksysb backup or other backup?
#tcopy /dev/rmt0
#restore -S2 -Tvqf /dev/rmt0

23 How will u install third party Packages (e.g. net backup agent)?
#./Install

24 How do u create a Paging space?
#mkps -a -s

25 What is default Paging space / Can we able to reduce the size in realtime?
/dev/hd6
We can change , but the changes will be get effected only after reboot
By using the command #sysdumpdev –P –p

26 How do you find history of a file set?
#lslpp –h

27 How do u remove a failed package installation?
#installp -C

28 Any idea about BLV?
Boot Logical Volume . It is a Image LV in a ROOTVG and occupies the default lvname of /dev/hd5
Which contains 4 parts that is
1. Kernel - Core of the OS
2. rc.boot Script - Which is called during the rc phase during
booting 3 times with different parameters used to
1. Access the rootvg (base devices configuration)
2. Activate the rootvg
3. Configure other than base devices
3. Basic Commands - Such as cfgmgr , bootinfo , cfgcon ,restbase which are called during the boot process at different stages
4. Compressed ODM - Which is used to verify and configure the devices .

29 How do u create a boot image?
#bosboot –a –d /dev/pvname

30 Any idea about SMS, How will u enter into it?
It is called System Management Services , used to configure the boot options in the Server as well used during NIM configuration also.
For that we have to press F1 key in Graphical Terminal ( ie. A machine with a Separate keyboard and Monitor) or else press 1 key in a ASCII Terminal after hearing 2 beeps during POST ,which will allow us to enter into SMS mode to do System boot maintenance activities

31 What are the file systems in root vg?
/, /usr, /var, /home, /tmp, /opt

32 Any idea about sticky bit?
It is the Extended base permission assigned to a Dir or a File , which helps for other users also can able to edit , modify the contents of a PUBLIC file or Directory .Only exception is the OWNER of the file or Dir can able to delete Or rename those…
Eg… # chmod 1777 , in this 777 is base permission and 1 is Extended permission.

33 How do u mirror a VG?
#lspv
#extendvg
#mirrorvg
#lsvg -l
If it is rootvg means BLV will not get copied into the new mirrored pv properly So we have to run
#bosboot -a -d /dev/pvname

34 How will u check whether a VG is mirrored or not?
#lsvg -l vgname
From the output , we can find out the mirroring by check the no.of PPs and LPs
ie.. no of PPs will be in multiples of 2 or 3 times of LPs if it is mirrored.

35 How do u make a mirror copy of a LV?
#mklvcopy -k

36 How do u check boot list?
#bootlist -m normal -o

37 How do u alter a boot order?
#bootlist -m normal

38 How do u check tape library?
#lsdev -Cc tape
From the output we can also find out the Availability or the Defined state of tape devices connected with the server.

39 Which file contains Password information’s?
/etc/passwd, /etc/security/passwd


40 How do we change new user resource limits?
First we have to put entry in /etc/security/limits. For that
#chsec -f /etc/security/limits -s username -a cpu= -1

41 Steps to unmirror a root vg?
#unmirrorvg rootvg
#chpv –c
#rmdev -dl
#bootlist –m normal

42 What is the default log location?
/dev/hd8 lv in a rootvg is called as default jfslog lv.

43 How do u increase a /home file system?
#chfs -a size = newsize /home

44 How will u check free space availability of a file system?
#df -k /filesystem name

45 Any idea about error code 518?
/usr not gets mounted in rc.boot phase 2 , then this error code will be displayed

46 What do u mean by error code 201?
Boot image corrupted. For Steps . refer book.

47 How do u transfer or export data from one PV to another M/c?
First
#varyoffvg
#exportvg
remove the pv and put it in another machine and run
#cfgmgr
and
#importvg -y

48 Differentiate between Standard VG and Big VG?
No of pv 32 128
No.of lvs 256 512
No of pp/vg 1016*32 1016*128

49 Can we able to copy data from one LV to another LV of different VG?
Yes…
#cplv -v -y

50 Which command is used to using mksysb backup?
Backup command is called in the background for doing mksysb backup


51 What is alt_disk_installation
Refer . book

52 What is difference between fileset and package
Fileset – Smallest installable unit
Package- Single installable image must be distributed and installed as a unit.

53 What is PTF and APARS
PTF is new fileset that fixes Previous system problem happened globally.
APAR is patch or fix to a unique problem in the systems

54 How do u remove the installed software.
#installp –u

55 What is command to configure console
#cfgcon

56 What is command to modify the entries in the /etc/inittab
#chitab and # mkitab #rmitab

57 How do u recover from non response bootingsystem.

58 Where does the customized devices stored
/etc/objrepos/

59 What is the difference between SMIT and smitty.
Smitty is ascii mode.we can run on any system.
SMIT is graphical mode

60 How to start group of NFS Deamons at a time
#startsrc -g nfs
#mknfs -N

61 What are device files

62 How do u change the ipaddress
Smitty mktcpip ifconfig eno

63 How do u add an two ip address for an interface.

64 How to know the LTG size of an PV
#lquerypv -M

65 How to disable the hotspare policy
#chdev -hn

66 How to remove the copy of a lv
#rmlvcopy lvname

67 Why is errpt command is used.

68 How do u restore the rootvg from tape device
Go to SMS mode and Select the boot option as boot from cdrom and Boot from bos cd , select the option of Change/Show installation settings and install , Select the install from the tape drive by placing the mksysb tape in it , And initiate the restoration of rootvg.

69 How do u exclude the a filesystem while doing mksysb backup
#mksysb -ief /dev/rmt0
Here the option “e” mentioned above will refer for a file /etc/exclude.rootvg for
the directories(filesystems) which we don’t want to be backed up.

70 How to change the user login shell
#chsh < path name of shell>
Or we can edit the file /etc/passwd and replace the shell with the shell which we want to assign to the user

71 Why is fuser command is used
It is used to find out the users who are all using a filesystem(fuser=filesystem user)
#fuser -cu /fs name ( to findout the users using the filesystem)
#fuser -ku /fs name ( to kill the users using the filesystem)

72 What is the default kernel location?
/usr/lib/boot/

73 How do u check kernel bit
#bootinfo -K
#getconf KERNEL_BITMODE

74 How do u check the hardware bit mode
#bootinfo -y
#getconf HARDWARE_BITMODE

75 What is the default odm directory
/etc/objrepos

76 What is quorum
Quorum is a feature of AIX , if it is enabled in a VG means , used to monitor the VG condition for 51% of VGDA information , In case if it goes beyond this 51% means, this feature will automatically varyoff the VG and send a mail to the root user stating that service is required for PV related issues..
#chvg -Qy to enable a VG with Quorum feature.


77 How do u remove the interface
#ifconfig down
#ifconfig < ipaddress> delete
#rmdev -dl en0

78 Which is the default file which stores the routing information.
/etc/gateways and /etc/rc.net

79 What is default pp size in a normal vg
Depending upon the size of the PV during the creation of that VG (1MB-1GB)

80 How do remove the entries of the device in the odm
#rmdev -dl

81 How do u find the File systems ( jfs or jfs2) ?
#lsjfs to findout the jfs filesystems
#lsjfs2 to findout the jfs2 filesystems



IBM-AIX QUESTION BANK

1. What are the models you worked ?
tell model name which you have worked.

2. what is the difference between P615 and P 630

P 615 P 630

Physical Memory 5 GB to 16 GB Physical memory 6.5 GB
CPU Speedy 1.2 Ghz to 1.45 Ghz 1.2 Ghz to 1.45 Ghz
Internal Hardisk capacity 1 T/B 72 G/B to 1.2 T/B


INSTALLATION AND BOOT SEQUENCE

1. What are the CD for AIX Installation [ S/W Sets] ?
a. BOS – Base operation System CD
b. Expansion S/W CD
c. Bonus S/W CD
d. LPP’s CD
e. AIX Tool for Linux

2. What are Installation Procedure?
a. CD Rom
b. Tape
c. Pre – Installation
d. NIM

3. What are the types of Installation?
a. New & Overwrite type [ New, No data to be preserved ].
b. Migration Installation [ From lower level to higher level upgrade But /tmp will be lost.
c. Preservation Installation [ Overwriting the O/S, userdata preserved, System data lost
/usr/var/tmp will be lost]

4. What is the diffrence between JFS & JFS2 File systems ?

JFS JFS 2
Journaled File System file size 64 G/B JFS 2 File size T/B
File System size 1 T/B File system size up to 4 Petabytes

5. In which file the Installation errors stay ?
/var/adm/devinstall.log

6 What are the Error Codes ?
1. 201 – Boot Image Corrupted
2. 223-229 Boot list invalid
3. 551,555,557 – File System Corrupted [JFS]
4. 553 – rtc/inittab Corrupted.
5. C31 - Console Problem
7. What is the command to view boot log ?
#alog –o –t boot

8. What is the command to configure devices ?
#cfgmgr

9. What is the command to display boot list ?
#bootlist –m normal –o

10. What is the command to change boot list order ?
#bootlist –m normal hdisk0

11. What is the command to change from 32 bit to 64 bit ?
#ln –sf /usr/lib/boot/unix_64/unix

12. What is the command to Re-Create Boot Image ?
#bosboot –a –d /dev/hdisk0

13. What will you do if boot image corrupted (ie) error 201 ?
Access root vg  through maintenance mode and check for the free space in / and /tmp.
Determine boot disk using # lslv –m hd5
Recreate boot image using command # bosboot –a –d /dev/hd1 and then shutdown & Restart.

14. What will you do if File system corrupted
Access root vg through Maintenance mode
And then run # fsck –y /dev/hd1
# fsck –y /dev/hd2

15. What will you do if super block corrupt
Access root vg through Maintenance mode
Then run # fsck –y /dev/hd1
Fsck can be used for any file system corruption.
Then to repairs
# ddcount=1 bs=4R skip=31 seck=1 if = /dev/hd1 of = /dev/hd1

16. What will you do it /etc/init tab corrupted ?
Check free space in /root, /tmp & /var
Check for wrong entry in /etc/initab file
Then restart the system.

17. What is boot strap program ?
Set of program in NVRAM to identify the boot partion in the boot device.

18. How many times cfgmgr run in boot process ?
During post – Base device configuration
Reboot 1, Reboot 3.

19. What are the field in /etc/initab ?
1st field – Identifier,
2nd field – Command,
3rd field – Action,
4th field – Run_Level.

20. What is the command to find whether user root logged in & logged off ?
# last root console
21. Command to find the kernal 32,62 bit ?
# bootinfo –y

22. Which file can you see boot log ?
/var/adm/ras/bootlog

23. Which file can you see the error installtion ?
/var/adm.devinstall.log.

BACKUP & SCHEDULING

1. What is the difference between mksysb & savevg commands ?
mksysb  to take rootvg backup
savevg  to take non – rootvg backup

2. What command to take rootvg backup
# mksysb /dev/rmt0

3. What command to take backup other vg’s ?
# savevg –if /dev/rmt0 /vgname.

4. What command to take backup of files & folders ?
# backup –if /dev/rmt0 /test/data
# tar –cvf /dev/rmt0 /test/data

5. What comman to restore backup taken by backup command ?
# restore –x –d –f /dev/rmt0

6. What command to restore backup of non - rootvg ?
# restvg –x –d –f /dev/rmt0

7. What command to copy from tape to tape ?
# tcopy /dev/rmt0 /dev/rmt1

8. What command to controol [ Eject, Rewind, Offline etc ] of tape drive ?
# tct/ -f /dev/rmt0 rewind ,eject

9. What command to restore rootvg [ mksysb ]
# restore –T-d –v –q –f /dev/rmt0

10. What is O level backup ?
It’s nothing but taking backup of all system data in a specified file system .

11. What command to take backup of Sunday ?
# backup –0 –vf /dev/rmt0 /data

12. What command to take backup on Saturday ?
# backup –6 –vf/dev/rnt0 /data

13. What command to find the tape block size ?
#tcopy /dev/rmt0

14. What command to check the block size of tape ?
# chdev –l rmt0 –a block_size=512


SCHEDULING

1. What is ‘at’ Command ?
Command to run a process only one time.

2. What command to list the field cronjobs ?
#crontab –l
0 – 59 Mins
1 – 23 Hours
1 – 31 Days
1 – 12 Months
0 – 6 Sun,Sat

3. What command to edit the fields of crontab ?
# crontab –e
Backup to be taken at specic time
# tar –cvf /dev/rmt0.

4. Which file can you deny & allow cron entry ?
/var/ad/crom/cron.allow
/var/adm/cron/cron.deny

PAGING SPACE

1. Paging space resides in which logical volume ?
Hd6

2. What is the recommended size of paging space
Twince the size of real memory

3. What command to list the paging space ?
#lsps –a

4. What command to see the usage of paging space ?
# lsps –s
Total paging space used
336 M/B 1%

5. What command to create a paging space ?
# smitty mkps

6. What command to increase the size of paging space ?
# smitty chps

7. What command to decrease paging space ?
# chps –d 2 paging 03
(ie) Decrease by 2 logical partition.

8. What command to remove paging space ?

#smitty rmps.
9. What command to activate paging space ?
#swapon –a /dev/hd6.

10. What command to deactivate paging space ?
# swapoff –a /dev/hd6

11. When is the paging space activated in booth ?
 Rcbootz

12. Where the file does the paging space stay ?
/etc/swapspaces.

MAINTENANCE LEVEL

1. What is the command to determine the maintenance level ?
# oslevel –r

2. What is the latest maintenance level in AIX 5.2 ?
5.2.0.0

3. PTF ?  Program Temporary Fix installed using command
# installp

4. APAR  Authorized Program Analysis Report installed using command
# instfix

5. What command to install software products
# installp
(or)
# smitty install_latest

6. What is the command to remove the installed S/W?
# smitty install_remove

7. What command to list the S/W installed?
# lslpp –l

8. What command to install a Fix [ Maintenance ]
# instfix –k IY2442 –d /dev/fd0

9. What is the command to check whether Fix installed correctly ?
#instfix –ik “IY2424”

ERROR DAEMON & SRC

1. What command it used to check whether that daemon is running ?
#ps –ef |grep errdemon

2. Which file that error daemon stay ?
/usr/lib/errdemon

3. When does error demon start in boot process
Rcboot3











/dev/err Virutal device
in memory Kernal

4. What are the types of error ?
1. H/W error
2. S/W error
3. Operator error
4. Unknown error.

5. What are the error levels severity ?
1. permanent
2. Temporary
3. Informational
4. Unknown.

6. What is the command to see the error log ?
# errpt –a
# errpt –d H [H/W]
# errpt –d S [S/W]

7. What is the command to clear the errorlog ?
# errclear

8. What is the command to increase the size of error log when it is full ?
#usr/lib/errdemon –s ____ [ size ]

SRC
1. What is the command to start a demon ?
# startsrc –g [ Demon name ]

2. What is the command to stop a demon ?
# stopsrc [Demon name ]

3. What command to restart a demon ?
# refrest [Demon name ]

4. What command to list the demons ?
# lssrc


ODM & PERFORMANCE

1. What are the types of ODM Database ?
a. Pre-defined database pddv , pdAT
b. Customised database cvdv , cvAT

2. What are the areas managed by ODM ?
Software,Hardware,NIM,SMIT menu,TCPIP & Errlog.

3. Three components of ODM ?
1. Object class
2. Object
3. Desripter

4. ODM Commands.
To customize Odm  odmcreate
To remove ODM  odmdrop
To remove object from ODM  odmdelete
To see info in ODM  odmget
To change the fields in object class  odmchange
To add object to ODM  odmadd

5. Where will the ODM store –Which file ?
/etc/objrepos
/usr/bin/objrepos
/usr/share/bin/objrepos


PERFORMANCE
VMSTAT
R sys pi po sr us id

||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||



0 Should be above 40%

20 to 30 2000
above memory ready
to be upgraded


0 is good

If more jobs in que
Cpu need to be increased

IOSTAT

The report has the TTY and CPU statistics to check the performance of Hard disk [pv ] .


NETSTAT

Displays the contents of varying network related data structures of active connections


NETWORK

1. What is the command to add IP address ?
#ifconfig ent0 192.168.5.25 |netmask 255.255.255.0
Broadcast 192.168.2.10

2. What is the command to configure network card
#mkinet

3. What is the command to change protocal
#mktcpip



4. What command to change the gateway address ?
#routeadd ent0 192.168.2.0
5. What is the command to bring down a network card ?
#ifconfig ent0 down

6. What is command to bring up a network card ?
#ifconfig ent0 up

7. what is the command to check the status of the node,duplex?
# ndd /dev/ent0 lnk-mode


USER ADMINISTRATION & NETWORK ADMINISTRATION

1. What is the command to create a new user ?
#mkuser –s [name] –d /export/home/username

2. What is the command to remove a user
# rmuser –d [prabu] [user + password removed ]

3. What is the command to change user attirbutes ?
#chuser –s [name] –d

4. What is the command to change password.
#passwd

5. user data stay in which file ?
/usr/lib/security/mkuser.sys

6. What command to create an administrator user ?
# mkuser –a [name]

7. What command to change user login shell ?
#chuser


QUESTIONS
1. I-Node
2. Root password recovery
3. Swap deactivate : Swappoff –a /dev/hd6  reboot to deactivate
4. RAID [Expansion]  Redundant Array inexperiment Disk
5. Default value of Disk quorum 51%
6. External storage devices [ Any work experience]
7. File system creation after VG
8. How the new devices to be added in to system
9. During migration installation where will you speicify the upgrade version
[version 4.3 to 5.2]
10. Difference between tar & CPIO command
[ tar  2.G/B backup,next it will not ask for next tape but CPIO ask next tape]
11. While taking rootvg backup what are the file systems that will be backup.
12. How will you confirm that the mirror vg has been copied successfully.
[lsvg –l vgname]
13. TCPIP & NFS
14. Backup command
15. More questions on LVM
16. Define how many hardisks required for VG


LVM



ROOT VG LV

LVCB







1. What is LVM ?
Feature availabe in AIX to increase or decrease the file system in on-line.



2. What are the feature in LVM.
1. VGDA
2. VGSA
3. LVCB
4. DISK QUORUM  51 % ABOVE SHOULD BE WORKING.

PERFORMANCE

[ VMSTAT 25 ]  5 OUTPUTS IN 2 SECOND INTERVAL

IMPORTANT PARAMETERS:

PI  Page –In  Non zero value then it is memory band PI – 20 to 30 %.
PO Page-Out
SCANRATE sr  200 % above memory needs to be upgraded.


USAGE OF CPU TIME






VS SY ID WA



+

= 100 %

User and system CPU usage is 100% then
It is CPU bound in this case id = 0 and wa =0

Therefore Total Idle time = id% + wa% = 0

The id [idle] time value should be above 40% for an normal system