AIX Commands You can't live without-Part 1

Introduction

As you know, AIX® has a vast array of commands that enable you to do a multitude of tasks. Depending on what you need to accomplish, you use only a certain subset of these commands. These subsets differ from user to user and from need to need. However, there are a few core commands that you commonly use. You need these commands either to answer your own questions or to provide answers to the queries of the support professionals.

In this article, I'll discuss some of these core commands. The intent is to provide a list that you can use as a ready reference. While the behavior of these commands should be identical in all releases of AIX, they have been only tested under AIX 5.3.

Note:
The bootinfo command discussed in the following paragraphs is NOT a user-level command and is NOT supported in AIX 4.2 or later.

Commands

Kernel

1)How would I know if I am running a 32-bit kernel or 64-bit kernel?

To display if the kernel is 32-bit enabled or 64-bit enabled, type:
bootinfo -K

2)How do I know if I am running a uniprocessor kernel or a multiprocessor kernel?

/unix is a symbolic link to the booted kernel. To find out what kernel mode is running, enter ls -l /unix and see what file /unix it links to. The following are the three possible outputs from the ls -l /unix command and their corresponding kernels:

/unix -> /usr/lib/boot/unix_up # 32 bit uniprocessor kernel /unix -> /usr/lib/boot/unix_mp # 32 bit multiprocessor kernel/unix -> /usr/lib/boot/unix_64 # 64 bit multiprocessor kernel

Note:
AIX 5L Version 5.3 does not support a uniprocessor kernel.

3)How can I change from one kernel mode to another?

During the installation process, one of the kernels, appropriate for the AIX version and the hardware in operation, is enabled by default. Let us use the method from the previous question and assume the 32-bit kernel is enabled. Let us also assume that you want to boot it up in the 64-bit kernel mode. This can be done by executing the following commands in sequence:

#ln -sf /usr/lib/boot/unix_64 /unix
#/usr/lib/boot/unix bosboot -ad /dev/hdiskxx
#shutdown -r

The /dev/hdiskxx directory is where the boot logical volume /dev/hd5 is located. To find out what xx is in hdiskxx, run the following command:

#lslv -m hd5

Note:
In AIX 5.2, the 32-bit kernel is installed by default. In AIX 5.3, the 64-bit kernel is installed on 64-bit hardware and the 32-bit kernel is installed on 32-bit hardware by default.

Hardware

4)How would I know if my machine is capable of running AIX 5L Version 5.3?

AIX 5L Version 5.3 runs on all currently supported CHRP (Common Hardware Reference Platform)-based POWER hardware.

5)How would I know if my machine is CHRP-based?

Run the prtconf command. If it's a CHRP machine, the string chrp appears on the Model Architecture line.

6)How would I know if my System p machine (hardware) is 32-bit or 64-bit?

To display if the hardware is 32-bit or 64-bit, type:

#bootinfo -y

7)How much real memory does my machine have?

To display real memory in kilobytes (KB), type one of the following:

#bootinfo -r

#lsattr -El sys0 -a realmem

8)Can my machine run the 64-bit kernel?

64-bit hardware is required to run the 64-bit kernel.

9)What are the values of attributes for devices in my system?

To list the current values of the attributes for the tape device, rmt0, type:

#lsattr -l rmt0 -E

10)To list the default values of the attributes for the tape device, rmt0, type:

#lsattr -l rmt0 -D

11)To list the possible values of the login attribute for the TTY device, tty0, type:

#lsattr -l tty0 -a login -R

12)To display system level attributes, type:

#lsattr -E -l sys0

13)How many processors does my system have?

To display the number of processors on your system, type:

#lscfg | grep proc

14)How many hard disks does my system have and which ones are in use?

To display the number of hard disks on your system, type:

#lspv

15)How do I list information about a specific physical volume?

To find details about hdisk1, for example, run the following command:

#lspv hdisk1

16)How do I get a detailed configuration of my system?

Type the following:

#lscfg

The following options provide specific information:
-p

Displays platform-specific device information. The flag is applicable to AIX 4.2.1 or later.
-v
Displays the VPD (Vital Product Database) found in the customized VPD object class.

For example, to display details about the tape drive, rmt0, type:

lscfg -vl rmt0

You can obtain very similar information by running the prtconf command.