Still celebrating National IT Professionals Day with 3 months of free Premium Membership. Use Code ITDAY17


How to configure a dump utility on AIX 5.3/6.1?

Posted on 2010-01-12
Medium Priority
Last Modified: 2013-11-17
I am new to working with AIX. We are trying to find a Linux Net Dump like utility for AIX. Also, any guides or information on how dumps work within AIX would be greatly appreciated!
Question by:Sultaana43
Welcome to Experts Exchange

Add your voice to the tech community where 5M+ people just like you are talking about what matters.

  • Help others & share knowledge
  • Earn cash & points
  • Learn & ask questions
LVL 68

Accepted Solution

woolmilkporc earned 2000 total points
ID: 26297101
Hi again,

AIX doesn't have a net dump facility.

Here kernel dumps always go to disk. You can define dedicated dump devices (primary/secondary)
or you can have the dump destination default to swap (paging) space.

If the dump goes to swap, the system tries to copy it to a defined destination at restart time.

I always recommend creating dump devices, so the dump doesn't get lost in case the copy destination was too small.

Creating dump devices consists in setting up a logical volume (or two) in rootvg and then making this/these known to AIX as dump destination(s).

1. Making an LV

First, estimate the dump size:

sysdumpdev -e

Divide the value displayed by (1024*1024), then divide the result by the partition size of rootvg to get the required number of partitions (rounded up).
Determine the partition size with

lsvg rootvg

It's displayed at the right under "PP size".

Example: sysdumpdev -e gives  "Estimated dump size in bytes: 314363084". This value divided by (1024*1024) gives 299,
this divided by a PP size of e.g. 32 gives 10 (rounded up).

Now create the LV:

mklv -t sysdump -y dumplv1 rootvg 10 hdisk#
with 10 being the number of partitions to allocate (see above). Specifying a desired hdisk# (e.g. hdisk0) is optional. If you have two or more disks in rootvg, it makes sense to create a secondary dump device on the other hdisk, e.g. with hdisk0 and hdisk1:

mklv -t sysdump -y dumplv1 rootvg 10 hdisk0mklv -t sysdump -y dumplv2 rootvg 10 hdisk1

2) Configure sysdump

sysdumpdev -p -P dumplv1
sysdumpdev -s -P dumplv2

means primary, -s means secondary and -P means "make the configuration permanent across reboots".

Now you have two dump devices.

If a kernel panic occurs, a dump will be invoked automatically (first to primary, and to secandary if primary is occupied or unavailable).
The following is dumped during the dump process.  
  • list of currently running processes and related information about the process
  • currently mounted filesystems, inode table and open file table
  • currently configured ttys and their status
  • memory buffers for data  
  • system buffers  
  • system variables and statistics
  • kernel's own record of process it is currently running.
You can start a dump manually by issuing

sysdumpstart -porsysdumpstart -s

with -p and -s meaning primary or secondary, respectively.

Attention: sysdumpstart will first "freeze" the system, then take the dump, then it will reboot!

If there is enough space to copy the dump to the /var/adm/ras directory, then it will be copied directly during reboot.
By default it is copied to /var/adm/ras/vmcore.x.

This destination is configurable:

sysdumpdev -d /var/adm/ras

Once the dump is copied to a file, you can examint it using the kdb tool.

I think explaining kdb would go far beyond the scope of your question, or am I wrong?

Anyway, "man kdb" gives some explanation,
and here is the AIX Troubleshooting Redbook:

If you need more information about dumps and troubleshooting, please let me know!



Author Closing Comment

ID: 31676280

Featured Post

Introducing the WatchGuard 420 Access Point

WatchGuard's newest access point includes an 802.11ac Wave 2 chipset, providing the fastest speeds for VoIP, video and music streaming, and large data file transfers. Additionally, enjoy the benefits of strong security as the 3rd radio delivers dedicated WIPS protection!

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Every server (virtual or physical) needs a console: and the console can be provided through hardware directly connected, software for remote connections, local connections, through a KVM, etc. This document explains the different types of consol…
This article outlines why you need to choose a backup solution that protects your entire environment – including your VMware ESXi and Microsoft Hyper-V virtualization hosts – not just your virtual machines.
Learn how to find files with the shell using the find and locate commands. Use locate to find a needle in a haystack.: With locate, check if the file still exists.: Use find to get the actual location of the file.:
This video shows how to set up a shell script to accept a positional parameter when called, pass that to a SQL script, accept the output from the statement back and then manipulate it in the Shell.

704 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question