Red Hat Knowledgebase

Netdump configuration requires two computers. One acts as the netdump server and the other one acts as the netdump client. Install the "netdump-server" package on the server and the "netdump" package on the client.

I. Configuration

On the netdump server, as root, type:

passwd netdump

and supply a password for netdump just like what you do to an ordinary user. Then do the following:

chkconfig netdump-server on
service netdump-server start

On the netdump client, edit /etc/sysconfig/netdump then uncomment and set the NETDUMPADDR variable to the IP address of the netdump server. For example:

NETDUMPADDR=10.199.243.39

Then execute:

service netdump propagate

and supply the netdump password that was configured on the netdump server. Finally, execute:

chkconfig netdump on
service netdump start

II. Testing

To test if the netdump configuration is correct, perform the following on the netdump client (Warning: it will crash the machine!):

sysctl -w kernel.sysrq=1
echo c > /proc/sysrq-trigger

This will crash the system and you will see a kernel dump on the netdump server in the directory /var/crash//. You will see the file "vmcore-incomplete" while the client is dumping data to the server. The file is renamed to "vmcore" once it is completed.

The size of "vmcore" will vary and may reach several gigs. On a system with 512Mb of RAM, the above test created a vmcore of approximately 510Mb.

III. Troubleshooting

Netdump client service startup failures are usually due to NIC or module incompatibility problems. You will notice "insmod" errors when this happens.

Netdump does not work for all NICs so make sure that yours is compatible. Below is a list of supported NICs at the time of writing:

1. Broadcom bcm57xx using the tg3 driver. Does not work with bcm5700 driver.
2. 3Com 3c59x
3. Intel eepro100, e100 and e1000
4. tlan
5. tulip