VERY IMPORTANT
Q1. What are your daily activities?
Ans. My daily activities include the following tasks:
1. To backup mksysb.
2. To work on LVM e.g. File system management.
3. To apply patches using instfix and emgr commands.
4. To manage daemons (Whether the daemons are working or not. If not working then to restart those daemons.). I get to know about these through Incident Management tickets.
5. Performance Monitoring using common AIX tools like sar, vmstat and iostat and ps.
6. Looking at errors using errpt command.
7. Creating LPARs, though its not very occasional activity.
8. Dynamic resource management among LPARs using DLPAR.
9. Client installation using NIM.
2. How AIX is different from other Unix Operating systems ..?
Ans : a..) LV M Concepts ( Policies …where you can optimize the performance )
b) ODM
c) Dynamic Kernel
d) Auto Configuration of devices (cfgmgr)
e) Dynamic increasing of file system
f) JFS & JFS Log..Prevents the file system corruption.
g) Booting from alternate Disk
h) Rootvg Cloning
3. How to install oracle on linux? What are the prerequisites to install oracle ?
Ans : Need to set kernel parameters, install necessary fixes, create required users and groups, set path and profile, exact installation procedure comes documented with oracle installation media.
4. How to u find the system is I/O bound
Ans : If the iowait value is more in the iostat output system can say I/O bound provided the disk balance are good.
5. How u find system is memory bond?
Ans : Buy observing the pi&po field in vmstat o/p.
6. How to see user resource limit
Ans : ulimit –a
7. Boot Process of AIX?
Ans : Post
Locate the blv using bootlist
Load the blv and pass control
Configure the device through cfgmgr
Start init and process /etc/inittab
8. How to recreate BLV?
Ans :Got on SMS mode – access rootvg with mounting then #bosbot –ad /dev/hdisk0 #shutdown –Fr
9.How to change the maintenance mode?
Ans : Init m
10.How to reset lost password of root?
Ans : Got ot SMS mode – access rootvg with mounting then #passwd then #shutdown –Fr
Device
What is the stage of cfgmgr?
Ans : Check predefined database.
Load device driver from odm and made entry on /dev directory
Put the entry in customized devices database.
Q.10 Write the command for changing maximum number of user process from 40 to 80?
Ans. # chdev -l sys0 -a maxuproc=80
Q.11 How do you configure a defined device?
Ans. # mkdev -l devname
Q.12 Write down the command for disabling tty0?
Ans. # chdev –l ‘tty0’ –a login=’disable’
5. How to make available disk to PV.
Ans: #chdev -l hdisk1 - a pv=yes
16. How to use chdev ..command … to change the block size of tape
Ans : chdev -l rmt0 block_size=1024
17. How to see the default attributes of tape or system
Ans : 1.) lsattr -E -l rmt0 -D
2.) lsattr -E -l sys0 -D
18. How to remove & delete the device(tape) information from database.
Ans : 1.)rmdev -l rmt0 -d
19. How to make defined device(tape) to available .
Ans : 1.)mkdev -l rmt0
20. How to see the real memory of the system ?
Ans : 1.)lsdev -Cc memory or
2.) lsattr -E -l mem0
21.how to check lun information of SAN enviroment in AIX
Ans : using lsdev
22. How to see the firmware
Ans : lsattr –el sys –a fwver
Filesystem
3. Lists out the Advantage of Having LVM .
1. Optimizing the LV for maximum performance
2. Increasing the filesystem size dynamically
3. Mirroring of LVs
4. Striping of logical volumes
4. What is the limitation of LVM ?
1. Maximum VGs per system is 255
2. Maximum PVs per VG is 32
3. Maximum LVs per VG is 256
4. Maximum PPs per PV is 1016 ( AIX 4.3 supports multiple numbers )
5. Striped logical volume can not be mirrored
6. Moving data acrross VG is not possible
7. Reducing the size of LV is not possible.
What is superblock
The first block on any file system that contain metadata of its like no of inode and free inode etc.
6. How to restricts the VG spaning on numbers of PVs? Is there any smit is available?
With mkvg command you have to use -d flag to limit the VG spanning across more disks
There is not smit available.
7. How to restricts I/O operation on particular PV?
# chpv -v r pvname
8. What is the Command used to migrate the PV & LV? Is it possible to migrate the PV between VGs if not possible, how to copy the LVs from one VG PV to other VG PVs.
1.) #migratepv
2.) It’s not possible
3.) calve
9.How will you create filesystem?
A. crfs -v fstype -g volgroup -m mountpt -p permission -a size
10.How will you convert normal vg to big vg.
A. chvg -B vgname
8.What is the use of synvg and synclvodm
A. syncvg:to update mirrored lv copy in a vg
synlvodm:Synchronizes or rebuilds the logical volume control block,
the device configuration database, and the volume group descriptor areas
on the physical volumes.
4.How many lvs will be created at the time of AIX installation?
A./dev/hd1 - /home, /dev/hd2- /usr, /dev/hd3-/tmp, /dev/hd4-/, /dev/hd5 - /boot,/dev/hd6 - paging, /dev/hd8 - /jfslog, /dev/hd9- /var,/dev/hd10 -/opt
5.What is use of /dev/hd7?
A. Not used
6-What is the difference between jfs & jfs2 ?
A. There are following difference-------
jfs jfs2
1-Inode size 128 Byte 512Byte
2-Max file size 64GB 4PB
3-Max filesystem size 1TB 4PB
4-Cmpresion yes no
5-jfslog-type General jfslog inline-jfslog
Minimum file system size not specify 16MB
Inode allocation static dynamic
7-What is inode?
A. This is indexnode containing the information about the file like filename, filesize, fileowner, filegroup, access date& time, Modification date & time etc.
8-How many pvs possible in Big VG & Scalable VG?
A. This is 128 & 1024
9-How will you define the VG?
A. # mkvg -s pp_size -t t-factor -y vg_name hsidkx
10.How will you change the normal VG to Big VG?
A. #chvg -B vg_name
11-What is t-factor?
A. This is the factor used for define the no.of PP,s in a PV within the VG,if we are putting the value of t-factor 2 it will extend the max no of pp,s per PV and reduced the max no of PV,s within the VG
13- How many max LV possible in a scalable VG?
A. These are 4096 per VG
Q33.What is the use of lvlstmajor command?
Ans- To knows the free Major Number.
Q34.How to increase the filesystem size, can we reduce the fs size?
Ans- #chfs -a size=+value /fsname, fs size can be reduce in Aix5.3 not in Aix 5.1
How will you move pp to particular disk?
Migratelp Lvname/lp no [/ copy no] Destpv[/ppartno
To move the first logical partitions of logical volumelv00 to hdisk
Migrate lv00/1 hdisk1
Q35.How to create LV?
Ans-#mklv -t lvtype -y lvname vgname no.of Lps pvname
t- for type it may be jfs,pagingspace,journallog,boot type.
Q36. How to replace the mirror disk from rootvg?
Ans-#unmirrorvg rootvg pvname
#sysdumpdev -p /dev/sysdumpnull
#reducevg rootvg pvname
#rmdev -l hdiskx -d
if mirror disk is bootable put #chpv -c hdiskx
Now remove faulty disk and put new one then run #cfgmgr
#extendvg rootvg hdisky
#mirrorvg -S rootvg hdisky
#bosboot -ad /dev/hdisky
#bootlist -m normal hdisky
Q37. What is Quorum?
Ans-This is the voting of VGDA,used to recover the data after a disk crash! ,if VGDA area is >51% ,then only the quorum will come in picture. Quorm is provide datat intrigrity, data redundancy from in mirrorvg.
17. If I have 4 CPUs and 2GB RAM and 2 Hard Disks, can I create 8 Partions?
19. How to migrate filesystem from one hard disk to another hard disk?
22. How to Configure SAN disk in Aix? How will you distinguish between normal disk and SAN disk?
3. How would you increase(Manage) the Filesystem size?
Ans. This depends upon the name of the filesystem. If its /usr then normally we have to increase the filesystem, because we don't have chances of compressing the files. In case of other filesystems like /var, we compress the old log files. Some times we inspect the data which is not required, we delete that after taking the backups and consulting the appropriate persons.
In case we have to increase the Filesystem size then we follow the procedure as:
To check the no. of free PPs in filesystems using "lsvg -p" command and the size of the PP in CG. Then we increase the filesystem size by:
chfs -a size=+NewSize(M\G\or 512 Bytes multiple) Name_of_FS
If the no. of free PPs is insufficient then we have to add new harddisk, extend
the VG and then run the chfs command again.
Q.21 What is the command for synchronizing a logical volume copy (mirror)?
Ans. # syncvg <name>
name could be volume group name , physical volume name or logical volume name.
Q.22 Write down the command for turning off a mirroring of a logical volume ?
Ans. # rmlvcopy <LVname> <no. of copies left>
Q.18. How to copy a LV ?
Ans. # cplv [ -v VolumeGroup ] [ -y NewLogicalVolume ] SourceLogicalVolume
Q.41 How do I get rid of a disk that is no longer really in the volume group?
Ans. # reducevg -d -f <vgname> <hdname>
or if the hdname can't be found:
# reducevg -d -f <vgname> <PVID>
Q.23 Can you define different Quotas on different filesystems for a single user?
Ans. Yes.
Q.35 What is LVCB ?
Ans. The logical volume control block (lvcb) is the first 512 bytes of a logical volume. This area holds important information such as the creation date of the logical volume,
information about mirrored copies, and possible mount points in a journaled filesystem.
Q.28. File systems - nbpi, etc., read the theory.
Ans. nbpi – number of bytes per inode.
This feature of filesystem is used when fragmentation of files are set. If a filesystem contains small files , then it is advantageous to keep the fragment size small , so that space is not wasted. Normally there is one inode created for every possible file in a filesystem. However in actual practice the number of inodes required are quite less. Therefore to save on space allocated for inodes , we specify the nbpi value.
Q.37. Why am I having trouble adding another disk to my VG?
Ans. a.) Not enough space left in the volume group descriptor area.(VGDA)
b.) Volume group can have a maximum of 32 disks in a volume group. ( 128 for big VG)
Difference between fsck –y and fsck –f
Ans : fsck –f: perform the fast check. It will not check that filesystem were umounted successfully.
FSCK –y : assumes a yes response to all questions asked by the fsck command
What are the 6 steps in fsck –y
1. Check Block and size
2. Check pathname
3. Check connectivity
4. Check reference counts
5. Check inode map
6. Check block map
How to create file system in raw hard disk?
Extendvg, mklv, crfs
What are the stanza in /etc/filesystem?
Dev=
Mount=
Log=
Vfs=
Check=
Type=
What is proc file system?
Contain info about all currently running process
calculation of pp
pv size = 80GB (81920 MB)
default no of pp = 1016
pp size = h/d in mb / default no of pp (81920/1016) = 80mb (>64) that’s why 128 mb
if we want to increase no of pp = t factor increase
no of pp = default no of pp * t factor ( 1016*2 = 2032 pp)
according that if we want to decrease size of PP then we have to increase t factor mean no of pp
ppsize now = 81920/2032 = 40mb means >32 that’s why it’s a 64 mb
6+
How you will maintain the password polices?
Using chuser and /etc/security/user
What is journaled file system?
It maintains a log in corresponding log device before committing any changes to LV and thus maintains integrity of file system.
Boot & dump * Error & ODM
Q.24. How to see memory activity ?
Ans. Using "sar", "vmstat"
What is difference between tar and cpio?
Ans : Tar handle symbolic link. cpio doesn’t.
What will do when odm in non-rootvg corrupted? (Rename vg also)
Ans :Exportvg and importvg
Why quorum is disabled in mirroring.
Ans : If it is mirrored within two pv VGDA ill be three, one ill have two VGDA means 66%, another ill have one VGDA means 33% , we can`t activate which failed with in 51% VGDA.. that’s what quorum is disabled in two mirrored condition.
Will file system extend or reduce update the vgda?
Ans : Yes as the use of pp is maintained by the vgda
Q.25. How to install software ?
Ans. # installp –a –Q –d <device> -f ‘all latest’
-a Applies one or more software products or updates.
-d Device Specifies where the installation media can be found.
-f ListFile Reads the names of the software products from ListFile.
Q.3 What are the packages to be installed for man pages & networking?
Ans. bos.info and bos.net
Q.4 How do you remove an installed package?
Ans. # installp –u –f listfile
Q.5 What is the use of mkszfile?
Ans. Saves the system state for reinstallation on the current system or another system. The mkszfile command overwrites an existing /image.data file with new information.
Q.6 Write down the command for checking bootlog?
Ans. # alog -o -t boot
Q.10. How to take the backup of a dump?
Ans. # snap -a -o <device>
Q.8. What is echo $$ ?
Ans. Returns current shell’s PID
Q.3. How to debug shell script ?
Ans. $ sh -x shellfile.
Q.3 What are the packages to be installed for man pages & networking?
Ans. bos.info and bos.net
Q.4 How do you remove an installed package?
Ans. # installp –u –f listfile
Q.5 What is the use of mkszfile?
Ans. Saves the system state for reinstallation on the current system or another system.The mkszfile command overwrites an existing /image.data file with new information.
17.How will you delete an entry from ODM?
Ans : #odmdelete
Q3.What is the component of BLV?
Ans- These are Reduce ODM, RAMfs, Aix Kernel, Aix Commands
Q4.How to Recover BLV if corrupted, which LED will Glow for that?
Ans-Boot the system by Cd or tape in Maintenance mode and access the rootvg then run #bosboot -ad /dev/hdiskx command set set the bootlist and restart the system. LED 557 will glow.
Q5.What is reduce ODM?
Ans-This is the copy of ODM which is required for Configure the base devices.
Q6.What is default dump device?
Ans : #/dev/hd6
Q7.How to set bootlist?
Ans : #bootlist -m normal/service device name priority wise
Q8.How to see boot device?
Ans : #bootinfo -b
Q9.What is SMS Mode?
Ans-This is System management service mode use for change the bootlist,see the configuration etc.
Q10.What is errpt?
Ans-This is a command used to display the error details of system. It reads the /var/adm/ras/errorlog file.
Q11.What is sticky bit & How to identify it?
Ans-This is the permission given to a directly so that the user can create the file but can not remove the file of other users. It will show a "t" with execute permission
Q15.What is the default run level in Aix? How would you see it?
Ans-This is 2 #who –r
Q17.How to know the Aix version?
Ans-#oslevel –r
95. How to inittiate system dump ?
Ans : # sysdumpstart -p (for primay )
# sysdumpstart -s (secondary)
96. What is SNAP command does.
Ans : Snap is a general purpose commnad use to gather the information about system
9. What is the command used to see the platform type of your system & what are the different type of platforms available .
Ans : 1.) bootinfo -p and oslevel to see the version.
2.) rs6k,rspc & chrp
11. What are different types of installation methods available ? what is different
Ans 1.)New & complete overwrite
2.) Preservation
3.) Migration installation.
12. What is dynamic kernel ? explain with example
Ans : The devices or some paramters if you are adding or deleting from the systems its not required to reboot.
Ie ..Kernel is updated dynamically.
Say ..example if you change the IPADDRESS , its not required to reboot the system .
Q.44 dtlogin ignores .profile?
Ans. Edit .dtprofile and remove # from the last line containing DTSOURCEPROFILE=true.
66. What is purpose of /etc/nologin , /etc/exclude.rootvg ,/etc/preserve.list .
Ans : /etc/nologin - it does not allows new users to login.
/etc/exclude.root - list of filesystesms , directories or files , does not get backedup during the system backup.(mksysb)
/etc/preserv.list - list of filesystems or files to be preserved during the preservation installation.
67. How to list the particular user attributes.
Ans : # lsuser -f user name
68. What is purpose of usrck ,pwdck & grpck.
Ans : # usrck -t user name checks the discripances on users information.
# pwd - checks password file for user discripancies.
# grpchk - checks the group informations
69. What is the purpose of ADMCHG flag in /etc/security/password file.
Ans:It will ask user to change the first time password.
70. What is the file used to limit the access time of particular user.
Ans :/etc/security/login..cfg
71. How to see how long system has been working .
Ans : uptime
72. Where the SU log activity is stored.
Ans : Var/adm/sulog
73. Where the failed login information is stored.
Ans : /etc/security/failedlogin
74. What is diffrence between /etc/objerepos,/usr/lib/objrepos& /usr/share/objrepos.
Ans :/etc/objrepos -stores the ODM objects of that systems.
/usr/lib/objrepos -stores the ODM objects ..that can be shared by other AIX systems.
/usr/shared/objrepos -contains information , that can be used by other unix systems
75. What are the commands used to manipulate the ODM.
Ans :#odmget , odmadd , odmdelete,odmdrop ,odchange,odmcreate & odmshow
76. What is flashing 888.
Ans :1. It may be H/W or system dump
77. What is 0c0 .
Ans : Successful complition of dump
78. How to find out the FRU number & micro code level (ROS or EC level) device.
Ans : #lscfg -vpl device name
lscfg -vpl hdisk0
79. What is ram file system?
Ans : File system resides on system memory …usually on system booting..
80. What is purpose of TMOUT Variables? Where its specified.
Ans : With help of TMOUT variable if the shell process is not active for period specify by the time out variable the process will be automatically terminated..
/etc/profile
81. What is advantage of Rsh (restricted ).
Ans :The following are not allowed.
1.) cd 2) ./ 3)changing path variable 4 ) Redirect output > or >>
82. What is purpose of ACL & what are command available
Ans : acledit , aclget & aclput)
83. How to copy acl from one file to another.
Ans : aclget file1 |aclput file2
84. How to view the extented permission.
Ans : ls -e filename
85. What is purpose of tcbck command.
Ans: verify the state of the files with the info in /etc/security/sysck.cfg
86. How to add a file sysck.cfg database
Ans : tcbck -a /home/rama/test12
87. Deleteting files from the sysck.cfg
Ans : tcbck -d /home/rama/test1
88. What is command used to analyze the system dump.
Ans : # crash imagefile kernelfilename
90. How to enable /disable the terminal
Ans : #penable & pdisable
91. How to set tty port for Bidirectionl mode ?
Ans :Share (port attributes )
How to see the Number of processor in the system ?
Ans : #lscfg -vp |grep Proc*
#lsdev -Cc processor
52. What is diffrence between sar & vmstat,iostat
Ans :Basic difference is SAR has time stamp but vmstat & iostat does not.
53. How to calculate CPU Ideal time & paging rate, what is purpose of the same.
Ans : #Vmstat interval number - it is done to see the condition of the system.
54. How to verify that system is CPU bounded or Resources Bounded (memory & IO)
Ans :If %sys+%usr >= 80 average the problem may be CPU Bounded.
If the paging rate is >= 1 then more paging activity is there in the system .it may be due to the memory or insufficient paging space.
55. How to increase the size of error log file.
Ans : # errdemon -s `size in bytes`
39. What is errpt? How the start & stop the error loging , how to clear the error log.
Ans :Errpt is error-reporting program. Its reports the contains of file /var/adm/ras/errorlog
2.)/usr/lib/errdaemon
3)errorstop
4.)errclear 0 (clear all errors )
40. What is the command used to see the Operating system level.
Ans : oslevel
41. How to see the fileset level ( bos.sysmgt.nim.master).
Ans: lslpp -l bos.sysmgt.nim.master
42. what is the smit past path used to upgrate to next modification level.
Ans: #smit update_all
43. Where the installp command output is stored? (smit )
Ans : #$HOME/smit.log
44. What is the meaning of applied, commited, broken & absolute?
Status of filesets .
45. How to clean up the failed software installation.
Ans : #installp
46. What is the purpose of lppchk
#lppchk -c to verify the checksum
#lppchk -v to verify the software parts..
47. What are the parts of software components?
#root,usr & share parts.
Backup
Q2. What are the problems encountered during creation of mksysb?
Ans. If creation of mksysb fails then it may have the problems like:
1. If the particular files are missing, mksysb creation fails. In that case you have to specify the files missing in /etc/exclude.rootvg and run mksysb with -e flag in addition to the other flags.
2. Some times the Filesystem space is insufficient. This can be due to installation of some new softwares. Normally the minimum Filesystem space required is 2.2 GB. Rest it depends upon the no. of softwares installed.
97. What is purpose of image.data & bosinst.data
Ans # image.data contains information about VG & LVS
#bosinst.data contains ..information about the installation flow control ..like method of installation,prompted or not.
98. How to restore the mksysb image of one systems to other system with different hardware.
Ans : Boot from the Installation CD , then choose to restore from mksysb tape , so that if any additional driver is required it will copy from the CD-ROM.
99. How to take backup of rootvg
Ans : #mksysb -i /dev/rmt0
100. How to view the mksysb tape & how to restore particular file from mksysb tape
Ans : # tctl -s4 -f /dev/rmt0
# restore -Tvf /dev/rmt0
# restore -xvf /dev/rmt0 filename.
101. How to rewind the tape.
Ans : # tctl -f /dev/rmt0 rewind
Q1. What are your daily activities?
Ans. My daily activities include the following tasks:
1. To backup mksysb.
2. To work on LVM e.g. File system management.
3. To apply patches using instfix and emgr commands.
4. To manage daemons (Whether the daemons are working or not. If not working then to restart those daemons.). I get to know about these through Incident Management tickets.
5. Performance Monitoring using common AIX tools like sar, vmstat and iostat and ps.
6. Looking at errors using errpt command.
7. Creating LPARs, though its not very occasional activity.
8. Dynamic resource management among LPARs using DLPAR.
9. Client installation using NIM.
2. How AIX is different from other Unix Operating systems ..?
Ans : a..) LV M Concepts ( Policies …where you can optimize the performance )
b) ODM
c) Dynamic Kernel
d) Auto Configuration of devices (cfgmgr)
e) Dynamic increasing of file system
f) JFS & JFS Log..Prevents the file system corruption.
g) Booting from alternate Disk
h) Rootvg Cloning
3. How to install oracle on linux? What are the prerequisites to install oracle ?
Ans : Need to set kernel parameters, install necessary fixes, create required users and groups, set path and profile, exact installation procedure comes documented with oracle installation media.
4. How to u find the system is I/O bound
Ans : If the iowait value is more in the iostat output system can say I/O bound provided the disk balance are good.
5. How u find system is memory bond?
Ans : Buy observing the pi&po field in vmstat o/p.
6. How to see user resource limit
Ans : ulimit –a
7. Boot Process of AIX?
Ans : Post
Locate the blv using bootlist
Load the blv and pass control
Configure the device through cfgmgr
Start init and process /etc/inittab
8. How to recreate BLV?
Ans :Got on SMS mode – access rootvg with mounting then #bosbot –ad /dev/hdisk0 #shutdown –Fr
9.How to change the maintenance mode?
Ans : Init m
10.How to reset lost password of root?
Ans : Got ot SMS mode – access rootvg with mounting then #passwd then #shutdown –Fr
Device
What is the stage of cfgmgr?
Ans : Check predefined database.
Load device driver from odm and made entry on /dev directory
Put the entry in customized devices database.
Q.10 Write the command for changing maximum number of user process from 40 to 80?
Ans. # chdev -l sys0 -a maxuproc=80
Q.11 How do you configure a defined device?
Ans. # mkdev -l devname
Q.12 Write down the command for disabling tty0?
Ans. # chdev –l ‘tty0’ –a login=’disable’
5. How to make available disk to PV.
Ans: #chdev -l hdisk1 - a pv=yes
16. How to use chdev ..command … to change the block size of tape
Ans : chdev -l rmt0 block_size=1024
17. How to see the default attributes of tape or system
Ans : 1.) lsattr -E -l rmt0 -D
2.) lsattr -E -l sys0 -D
18. How to remove & delete the device(tape) information from database.
Ans : 1.)rmdev -l rmt0 -d
19. How to make defined device(tape) to available .
Ans : 1.)mkdev -l rmt0
20. How to see the real memory of the system ?
Ans : 1.)lsdev -Cc memory or
2.) lsattr -E -l mem0
21.how to check lun information of SAN enviroment in AIX
Ans : using lsdev
22. How to see the firmware
Ans : lsattr –el sys –a fwver
Filesystem
3. Lists out the Advantage of Having LVM .
1. Optimizing the LV for maximum performance
2. Increasing the filesystem size dynamically
3. Mirroring of LVs
4. Striping of logical volumes
4. What is the limitation of LVM ?
1. Maximum VGs per system is 255
2. Maximum PVs per VG is 32
3. Maximum LVs per VG is 256
4. Maximum PPs per PV is 1016 ( AIX 4.3 supports multiple numbers )
5. Striped logical volume can not be mirrored
6. Moving data acrross VG is not possible
7. Reducing the size of LV is not possible.
What is superblock
The first block on any file system that contain metadata of its like no of inode and free inode etc.
6. How to restricts the VG spaning on numbers of PVs? Is there any smit is available?
With mkvg command you have to use -d flag to limit the VG spanning across more disks
There is not smit available.
7. How to restricts I/O operation on particular PV?
# chpv -v r pvname
8. What is the Command used to migrate the PV & LV? Is it possible to migrate the PV between VGs if not possible, how to copy the LVs from one VG PV to other VG PVs.
1.) #migratepv
2.) It’s not possible
3.) calve
9.How will you create filesystem?
A. crfs -v fstype -g volgroup -m mountpt -p permission -a size
10.How will you convert normal vg to big vg.
A. chvg -B vgname
8.What is the use of synvg and synclvodm
A. syncvg:to update mirrored lv copy in a vg
synlvodm:Synchronizes or rebuilds the logical volume control block,
the device configuration database, and the volume group descriptor areas
on the physical volumes.
4.How many lvs will be created at the time of AIX installation?
A./dev/hd1 - /home, /dev/hd2- /usr, /dev/hd3-/tmp, /dev/hd4-/, /dev/hd5 - /boot,/dev/hd6 - paging, /dev/hd8 - /jfslog, /dev/hd9- /var,/dev/hd10 -/opt
5.What is use of /dev/hd7?
A. Not used
6-What is the difference between jfs & jfs2 ?
A. There are following difference-------
jfs jfs2
1-Inode size 128 Byte 512Byte
2-Max file size 64GB 4PB
3-Max filesystem size 1TB 4PB
4-Cmpresion yes no
5-jfslog-type General jfslog inline-jfslog
Minimum file system size not specify 16MB
Inode allocation static dynamic
7-What is inode?
A. This is indexnode containing the information about the file like filename, filesize, fileowner, filegroup, access date& time, Modification date & time etc.
8-How many pvs possible in Big VG & Scalable VG?
A. This is 128 & 1024
9-How will you define the VG?
A. # mkvg -s pp_size -t t-factor -y vg_name hsidkx
10.How will you change the normal VG to Big VG?
A. #chvg -B vg_name
11-What is t-factor?
A. This is the factor used for define the no.of PP,s in a PV within the VG,if we are putting the value of t-factor 2 it will extend the max no of pp,s per PV and reduced the max no of PV,s within the VG
13- How many max LV possible in a scalable VG?
A. These are 4096 per VG
Q33.What is the use of lvlstmajor command?
Ans- To knows the free Major Number.
Q34.How to increase the filesystem size, can we reduce the fs size?
Ans- #chfs -a size=+value /fsname, fs size can be reduce in Aix5.3 not in Aix 5.1
How will you move pp to particular disk?
Migratelp Lvname/lp no [/ copy no] Destpv[/ppartno
To move the first logical partitions of logical volumelv00 to hdisk
Migrate lv00/1 hdisk1
Q35.How to create LV?
Ans-#mklv -t lvtype -y lvname vgname no.of Lps pvname
t- for type it may be jfs,pagingspace,journallog,boot type.
Q36. How to replace the mirror disk from rootvg?
Ans-#unmirrorvg rootvg pvname
#sysdumpdev -p /dev/sysdumpnull
#reducevg rootvg pvname
#rmdev -l hdiskx -d
if mirror disk is bootable put #chpv -c hdiskx
Now remove faulty disk and put new one then run #cfgmgr
#extendvg rootvg hdisky
#mirrorvg -S rootvg hdisky
#bosboot -ad /dev/hdisky
#bootlist -m normal hdisky
Q37. What is Quorum?
Ans-This is the voting of VGDA,used to recover the data after a disk crash! ,if VGDA area is >51% ,then only the quorum will come in picture. Quorm is provide datat intrigrity, data redundancy from in mirrorvg.
17. If I have 4 CPUs and 2GB RAM and 2 Hard Disks, can I create 8 Partions?
19. How to migrate filesystem from one hard disk to another hard disk?
22. How to Configure SAN disk in Aix? How will you distinguish between normal disk and SAN disk?
3. How would you increase(Manage) the Filesystem size?
Ans. This depends upon the name of the filesystem. If its /usr then normally we have to increase the filesystem, because we don't have chances of compressing the files. In case of other filesystems like /var, we compress the old log files. Some times we inspect the data which is not required, we delete that after taking the backups and consulting the appropriate persons.
In case we have to increase the Filesystem size then we follow the procedure as:
To check the no. of free PPs in filesystems using "lsvg -p" command and the size of the PP in CG. Then we increase the filesystem size by:
chfs -a size=+NewSize(M\G\or 512 Bytes multiple) Name_of_FS
If the no. of free PPs is insufficient then we have to add new harddisk, extend
the VG and then run the chfs command again.
Q.21 What is the command for synchronizing a logical volume copy (mirror)?
Ans. # syncvg <name>
name could be volume group name , physical volume name or logical volume name.
Q.22 Write down the command for turning off a mirroring of a logical volume ?
Ans. # rmlvcopy <LVname> <no. of copies left>
Q.18. How to copy a LV ?
Ans. # cplv [ -v VolumeGroup ] [ -y NewLogicalVolume ] SourceLogicalVolume
Q.41 How do I get rid of a disk that is no longer really in the volume group?
Ans. # reducevg -d -f <vgname> <hdname>
or if the hdname can't be found:
# reducevg -d -f <vgname> <PVID>
Q.23 Can you define different Quotas on different filesystems for a single user?
Ans. Yes.
Q.35 What is LVCB ?
Ans. The logical volume control block (lvcb) is the first 512 bytes of a logical volume. This area holds important information such as the creation date of the logical volume,
information about mirrored copies, and possible mount points in a journaled filesystem.
Q.28. File systems - nbpi, etc., read the theory.
Ans. nbpi – number of bytes per inode.
This feature of filesystem is used when fragmentation of files are set. If a filesystem contains small files , then it is advantageous to keep the fragment size small , so that space is not wasted. Normally there is one inode created for every possible file in a filesystem. However in actual practice the number of inodes required are quite less. Therefore to save on space allocated for inodes , we specify the nbpi value.
Q.37. Why am I having trouble adding another disk to my VG?
Ans. a.) Not enough space left in the volume group descriptor area.(VGDA)
b.) Volume group can have a maximum of 32 disks in a volume group. ( 128 for big VG)
Difference between fsck –y and fsck –f
Ans : fsck –f: perform the fast check. It will not check that filesystem were umounted successfully.
FSCK –y : assumes a yes response to all questions asked by the fsck command
What are the 6 steps in fsck –y
1. Check Block and size
2. Check pathname
3. Check connectivity
4. Check reference counts
5. Check inode map
6. Check block map
How to create file system in raw hard disk?
Extendvg, mklv, crfs
What are the stanza in /etc/filesystem?
Dev=
Mount=
Log=
Vfs=
Check=
Type=
What is proc file system?
Contain info about all currently running process
calculation of pp
pv size = 80GB (81920 MB)
default no of pp = 1016
pp size = h/d in mb / default no of pp (81920/1016) = 80mb (>64) that’s why 128 mb
if we want to increase no of pp = t factor increase
no of pp = default no of pp * t factor ( 1016*2 = 2032 pp)
according that if we want to decrease size of PP then we have to increase t factor mean no of pp
ppsize now = 81920/2032 = 40mb means >32 that’s why it’s a 64 mb
6+
How you will maintain the password polices?
Using chuser and /etc/security/user
What is journaled file system?
It maintains a log in corresponding log device before committing any changes to LV and thus maintains integrity of file system.
Boot & dump * Error & ODM
Q.24. How to see memory activity ?
Ans. Using "sar", "vmstat"
What is difference between tar and cpio?
Ans : Tar handle symbolic link. cpio doesn’t.
What will do when odm in non-rootvg corrupted? (Rename vg also)
Ans :Exportvg and importvg
Why quorum is disabled in mirroring.
Ans : If it is mirrored within two pv VGDA ill be three, one ill have two VGDA means 66%, another ill have one VGDA means 33% , we can`t activate which failed with in 51% VGDA.. that’s what quorum is disabled in two mirrored condition.
Will file system extend or reduce update the vgda?
Ans : Yes as the use of pp is maintained by the vgda
Q.25. How to install software ?
Ans. # installp –a –Q –d <device> -f ‘all latest’
-a Applies one or more software products or updates.
-d Device Specifies where the installation media can be found.
-f ListFile Reads the names of the software products from ListFile.
Q.3 What are the packages to be installed for man pages & networking?
Ans. bos.info and bos.net
Q.4 How do you remove an installed package?
Ans. # installp –u –f listfile
Q.5 What is the use of mkszfile?
Ans. Saves the system state for reinstallation on the current system or another system. The mkszfile command overwrites an existing /image.data file with new information.
Q.6 Write down the command for checking bootlog?
Ans. # alog -o -t boot
Q.10. How to take the backup of a dump?
Ans. # snap -a -o <device>
Q.8. What is echo $$ ?
Ans. Returns current shell’s PID
Q.3. How to debug shell script ?
Ans. $ sh -x shellfile.
Q.3 What are the packages to be installed for man pages & networking?
Ans. bos.info and bos.net
Q.4 How do you remove an installed package?
Ans. # installp –u –f listfile
Q.5 What is the use of mkszfile?
Ans. Saves the system state for reinstallation on the current system or another system.The mkszfile command overwrites an existing /image.data file with new information.
17.How will you delete an entry from ODM?
Ans : #odmdelete
Q3.What is the component of BLV?
Ans- These are Reduce ODM, RAMfs, Aix Kernel, Aix Commands
Q4.How to Recover BLV if corrupted, which LED will Glow for that?
Ans-Boot the system by Cd or tape in Maintenance mode and access the rootvg then run #bosboot -ad /dev/hdiskx command set set the bootlist and restart the system. LED 557 will glow.
Q5.What is reduce ODM?
Ans-This is the copy of ODM which is required for Configure the base devices.
Q6.What is default dump device?
Ans : #/dev/hd6
Q7.How to set bootlist?
Ans : #bootlist -m normal/service device name priority wise
Q8.How to see boot device?
Ans : #bootinfo -b
Q9.What is SMS Mode?
Ans-This is System management service mode use for change the bootlist,see the configuration etc.
Q10.What is errpt?
Ans-This is a command used to display the error details of system. It reads the /var/adm/ras/errorlog file.
Q11.What is sticky bit & How to identify it?
Ans-This is the permission given to a directly so that the user can create the file but can not remove the file of other users. It will show a "t" with execute permission
Q15.What is the default run level in Aix? How would you see it?
Ans-This is 2 #who –r
Q17.How to know the Aix version?
Ans-#oslevel –r
95. How to inittiate system dump ?
Ans : # sysdumpstart -p (for primay )
# sysdumpstart -s (secondary)
96. What is SNAP command does.
Ans : Snap is a general purpose commnad use to gather the information about system
9. What is the command used to see the platform type of your system & what are the different type of platforms available .
Ans : 1.) bootinfo -p and oslevel to see the version.
2.) rs6k,rspc & chrp
11. What are different types of installation methods available ? what is different
Ans 1.)New & complete overwrite
2.) Preservation
3.) Migration installation.
12. What is dynamic kernel ? explain with example
Ans : The devices or some paramters if you are adding or deleting from the systems its not required to reboot.
Ie ..Kernel is updated dynamically.
Say ..example if you change the IPADDRESS , its not required to reboot the system .
Q.44 dtlogin ignores .profile?
Ans. Edit .dtprofile and remove # from the last line containing DTSOURCEPROFILE=true.
66. What is purpose of /etc/nologin , /etc/exclude.rootvg ,/etc/preserve.list .
Ans : /etc/nologin - it does not allows new users to login.
/etc/exclude.root - list of filesystesms , directories or files , does not get backedup during the system backup.(mksysb)
/etc/preserv.list - list of filesystems or files to be preserved during the preservation installation.
67. How to list the particular user attributes.
Ans : # lsuser -f user name
68. What is purpose of usrck ,pwdck & grpck.
Ans : # usrck -t user name checks the discripances on users information.
# pwd - checks password file for user discripancies.
# grpchk - checks the group informations
69. What is the purpose of ADMCHG flag in /etc/security/password file.
Ans:It will ask user to change the first time password.
70. What is the file used to limit the access time of particular user.
Ans :/etc/security/login..cfg
71. How to see how long system has been working .
Ans : uptime
72. Where the SU log activity is stored.
Ans : Var/adm/sulog
73. Where the failed login information is stored.
Ans : /etc/security/failedlogin
74. What is diffrence between /etc/objerepos,/usr/lib/objrepos& /usr/share/objrepos.
Ans :/etc/objrepos -stores the ODM objects of that systems.
/usr/lib/objrepos -stores the ODM objects ..that can be shared by other AIX systems.
/usr/shared/objrepos -contains information , that can be used by other unix systems
75. What are the commands used to manipulate the ODM.
Ans :#odmget , odmadd , odmdelete,odmdrop ,odchange,odmcreate & odmshow
76. What is flashing 888.
Ans :1. It may be H/W or system dump
77. What is 0c0 .
Ans : Successful complition of dump
78. How to find out the FRU number & micro code level (ROS or EC level) device.
Ans : #lscfg -vpl device name
lscfg -vpl hdisk0
79. What is ram file system?
Ans : File system resides on system memory …usually on system booting..
80. What is purpose of TMOUT Variables? Where its specified.
Ans : With help of TMOUT variable if the shell process is not active for period specify by the time out variable the process will be automatically terminated..
/etc/profile
81. What is advantage of Rsh (restricted ).
Ans :The following are not allowed.
1.) cd 2) ./ 3)changing path variable 4 ) Redirect output > or >>
82. What is purpose of ACL & what are command available
Ans : acledit , aclget & aclput)
83. How to copy acl from one file to another.
Ans : aclget file1 |aclput file2
84. How to view the extented permission.
Ans : ls -e filename
85. What is purpose of tcbck command.
Ans: verify the state of the files with the info in /etc/security/sysck.cfg
86. How to add a file sysck.cfg database
Ans : tcbck -a /home/rama/test12
87. Deleteting files from the sysck.cfg
Ans : tcbck -d /home/rama/test1
88. What is command used to analyze the system dump.
Ans : # crash imagefile kernelfilename
90. How to enable /disable the terminal
Ans : #penable & pdisable
91. How to set tty port for Bidirectionl mode ?
Ans :Share (port attributes )
How to see the Number of processor in the system ?
Ans : #lscfg -vp |grep Proc*
#lsdev -Cc processor
52. What is diffrence between sar & vmstat,iostat
Ans :Basic difference is SAR has time stamp but vmstat & iostat does not.
53. How to calculate CPU Ideal time & paging rate, what is purpose of the same.
Ans : #Vmstat interval number - it is done to see the condition of the system.
54. How to verify that system is CPU bounded or Resources Bounded (memory & IO)
Ans :If %sys+%usr >= 80 average the problem may be CPU Bounded.
If the paging rate is >= 1 then more paging activity is there in the system .it may be due to the memory or insufficient paging space.
55. How to increase the size of error log file.
Ans : # errdemon -s `size in bytes`
39. What is errpt? How the start & stop the error loging , how to clear the error log.
Ans :Errpt is error-reporting program. Its reports the contains of file /var/adm/ras/errorlog
2.)/usr/lib/errdaemon
3)errorstop
4.)errclear 0 (clear all errors )
40. What is the command used to see the Operating system level.
Ans : oslevel
41. How to see the fileset level ( bos.sysmgt.nim.master).
Ans: lslpp -l bos.sysmgt.nim.master
42. what is the smit past path used to upgrate to next modification level.
Ans: #smit update_all
43. Where the installp command output is stored? (smit )
Ans : #$HOME/smit.log
44. What is the meaning of applied, commited, broken & absolute?
Status of filesets .
45. How to clean up the failed software installation.
Ans : #installp
46. What is the purpose of lppchk
#lppchk -c to verify the checksum
#lppchk -v to verify the software parts..
47. What are the parts of software components?
#root,usr & share parts.
Backup
Q2. What are the problems encountered during creation of mksysb?
Ans. If creation of mksysb fails then it may have the problems like:
1. If the particular files are missing, mksysb creation fails. In that case you have to specify the files missing in /etc/exclude.rootvg and run mksysb with -e flag in addition to the other flags.
2. Some times the Filesystem space is insufficient. This can be due to installation of some new softwares. Normally the minimum Filesystem space required is 2.2 GB. Rest it depends upon the no. of softwares installed.
97. What is purpose of image.data & bosinst.data
Ans # image.data contains information about VG & LVS
#bosinst.data contains ..information about the installation flow control ..like method of installation,prompted or not.
98. How to restore the mksysb image of one systems to other system with different hardware.
Ans : Boot from the Installation CD , then choose to restore from mksysb tape , so that if any additional driver is required it will copy from the CD-ROM.
99. How to take backup of rootvg
Ans : #mksysb -i /dev/rmt0
100. How to view the mksysb tape & how to restore particular file from mksysb tape
Ans : # tctl -s4 -f /dev/rmt0
# restore -Tvf /dev/rmt0
# restore -xvf /dev/rmt0 filename.
101. How to rewind the tape.
Ans : # tctl -f /dev/rmt0 rewind
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