IBM AIX Interview Questions and Answers

by Subashini, on Jul 29, 2022 11:14:07 PM

Q1. How do I know if my volume group is normal, big, or scalable?

Ans

Run the lsvg command on the volume group and look at the value for MAX PVs. The value is 32 for normal, 128 for big, and 1,024 for the scalable volume group.

Q2. How do I create a volume group?

Ans

Use the following command, where partition_size sets the number of megabytes (MB) in each physical partition where the partition_size is expressed in units of MB from one through 1,024. (It’s one through 131,072 for AIX 5.3.)
mkvg -y name_of_volume_group -s partition_size list_of_hard_disks
The partition_size variable must be equal to a power of two (for example one, two, four, or eight). The default value for standard and big volume groups is the lowest value to remain within the limitation of 1,016 physical partitions per physical volume. The default value for scalable volume groups is the lowest value to accommodate 2,040 physical partitions per physical volume.

Q3. How can I change the characteristics of a volume group?

Ans

You use the chvg command to change the characteristics of a volume group.

Q4. How do I create a logical volume?

Ans

mklv -y name_of_logical_volume name_of_volume_group number_of_partition

Q5. How do I increase the size of a logical volume?

Ans

To increase the size of the logical volume represented by the lv05 directory by three logical partitions, for example, type extendlv lv05 3.

Q6. How do I display all logical volumes that are part of a volume group (e,g, rootvg)?

Ans

You can display all logical volumes that are part of rootvg by typing the following command: #lsvg -l rootvg/

Q7. How do I list information about logical volumes?

Ans

Run the following command to display information about the logical volume #lv1: lslv lv1.

Q8. How can I clone the rootvg?

Ans

You can run the alt_disk_copy command to copy the current rootvg to an alternate disk. The following example shows how to clone the rootvg to hdisk1: alt_disk_copy -d hdisk1.

Q9. How do I replace a disk?

Ans

extendvg VolumeGroupName hdisk_new
migratepv hdisk_bad hdisk_new
reducevg -d VolumeGroupName hdisk_bad

Q10. How do I mirror a logical volume?

Ans

mklvcopy LogicalVolumeName Numberofcopies
syncvg VolumeGroupName

Q11. How can I display or set values for network parameters?

Ans

The no command sets or displays current or next boot values for network tuning parameters

Q12. How do I get the IP address of my machine?

Ans

Type one of the following: ifconfig -a or host Fully_Qualified_Host_Name. For example, host cyclop.austin.ibm.com.

Q13. How do I identify the network interfaces on my server?

Ans

Either of the following two commands will display the network interfaces: lsdev -Cc if or ifconfig -a. To get information about one specific network interface, for eaxample tr0, run the command ifconfig tr0.

Q14. How do I activate a network interface?

Ans

To activate the network interface tr0, run the command ifconfig tr0 up.

Q15. How do I display routing table, interface, and protocol information?

Ans

To display routing table information for an Internet interface, type netstat -r -f inet. To display interface information for an Internet interface, type netstat -i -f inet. To display statistics for each protocol, type netstat -s -f inet.16.

Q16. How will you create a file if a disk is given to you?

Ans

mkvg –y datavg –s 128 hdisk1 (pv name)
mklv -y datalv –t jfs2 datavg 1
crfs –v jfs2 –d datalv –g datavg –a size=10M –m /fs1

Q17. What is the Difference between JFS & JFS2?

Ans

JFS:

JFS is a normal filesystem. We cannot create large files in JFS.
Files can be accessed dynamically.
Max file system size=1TB
Max file size=64GB
Inode size=128b

JFS2:

Can create a large-size filesystem.
Files can be accessed accordingly as required. (not randomly or sequentially)
Max files system size=4PB
Max file size=4PB
Inode size=512

Q18. How will you find the inode number?

Ans

ls –li
istat /etc/passwd

Q19. How will you find LTG size?

Ans

lsvg vgname
lquerypv –M hdiskname

Q20. How will you change LTG size?

Ans

rmdev -l hdiskx
chdev -l hdiskx -a max_transfer=0*80000
mkdev -l hdiskx

Q21. What is the Mirroring concept?

Ans

Check disk size belong to vg, take two same size disk to mirror
bootinfo –s hdisk2
lsvg –p rootvg
Add one more disk of the same size of already have disk having rootvg.
extendvg rootvg hdisk2
lsvg –p rootvg
Now mirror vg with background sync LV. It sync LVs in the background with new LVs
mirrorvg –s rootvg
Create a boot image
bosboot –ad /dev/hdisk2
bosboot –ad /dev/hdisk1
Add a blv
record of the newly added disk first checks and then add.
bootlist –m normal -o
bootlist –m normal hdisk2 hdisk1

Q22. How will you unmirror a VG if a PV gets failed?

Ans

First, check the blv record using,
bootlist –m normal –o
Remove the old blv record, using
chpv –c hdisk2
bootlist –m normal hdisk1
bootlist –m normal hdisk2
Now unmirrorvg
unmirrorvg rootvg hdisk2
reducevg rootvg hdisk2
lsvg –p rootvg
lspv
bootlist –m normal –o

Q23. What is T – Factor?

Ans

T – factor means that it will change the pp size to increase the efficiency of vg
chvg –t16 datavg
Cal-if suppose that datavg pp size is 1016 we can take t factor is 16 then it comes to 2048 and pv contains in vg is 2.

Q24. What is the default PP Size in AIX?

Ans

128MB

Q25. How will you rename a VG?

Ans

Unmount all filesystems in VG.
umount /test (mount point name)
varyoffvg datavg
exportvg datavg0
Importvg with new name
importvg –y newvg hdisk4

Q26. What is the major number?

Ans

A major number refers to a type of device. A device number is a major number, and a minor number specifies a particular device of that type or sometimes the operation mode of that device type.

Q27. What are the error levels severity?

Ans

permanent
Temporary
Informational
Unknown.

Q28. Two states of device availability and explain them?

Ans

Available state and defined state. When the device is in a defined state it means it cannot use. Not in a ready state. Run cfgmgr try to make available known in the system that device. Available state means that device is ready to use

lsdev –Cc disk

It displays which disks are available

Q29. How to change a 64-bit kernel to a 32-bit kernel?

Ans

Modify the /usr/lib/boot/Unix directory and the /Unix directory to be a symbolic link to the binary for the desired kernel.
Run the bosboot command to write a new system boot image.
Reboot the system.

The path name of the 64-bit kernel is /usr/lib/boot/unix_64, and the
path name of the multiprocessor versions of the 32-bit kernel is

/usr/lib/boot/unix_mp.
ln -sf /usr/lib/boot/unix_mp /unix
ln -sf /usr/lib/boot/unix_mp /usr/lib/boot/unix
lslv -m hd5
bosboot -ad /dev/ipldevice
shutdown -Fr
bootinfo -K (should now be 32)

Q30. How to change a 32 bit kernel to 64 bit kernel?

Ans

To truly change the kernel to 64-bit from 32-bit, the system must be at the AIX® 5.1 or AIX 5.2levels.

bootinfo –y

It shows a kernel is either 32-bit or 64-bit.