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23.2. Configuring the kdump Service

There are three common means of configuring the kdump service: at the first boot, using the Kernel Dump Configuration graphical utility, and doing so manually on the command line.

Disable IOMMU on Intel chipsets

A limitation in the current implementation of the Intel IOMMU driver can occasionally prevent the kdump service from capturing the core dump image. To use kdump on Intel architectures reliably, it is advised that the IOMMU support is disabled.

23.2.1. Configuring the kdump at First Boot

When the system boots for the first time, the firstboot application is launched to guide the user through the initial configuration of the freshly installed system. To configure kdump, navigate to the Kdump section and follow the instructions below.

Make sure the system has enough memory

Unless the system has enough memory, this option will not be available. For the information on minimum memory requirements, refer to the Hardware Overview section of the Fedora 17 Release Notes. When the kdump crash recovery is enabled, the minimum memory requirements increase by the amount of memory reserved for it. This value is determined by the user, and defaults to 128 MB plus 64 MB for each TB of physical memory (that is, a total of 192 MB for a system with 1 TB of physical memory).

23.2.1.1. Enabling the Service

To allow the kdump daemon to start at boot time, select the Enable kdump? checkbox. This will enable the service and start it for the current session. Similarly, unselecting the checkbox will disable it for and stop the service immediately.

23.2.1.2. Configuring the Memory Usage

To configure the amount of memory that is reserved for the kdump kernel, click the up and down arrow buttons next to the Kdump Memory field to increase or decrease the value. Notice that the Usable System Memory field changes accordingly showing you the remaining memory that will be available to the system.