32.2.2. Using the Kernel Dump Configuration Utility
system-config-kdumpat a shell prompt. You will be presented with a window as shown in Figure 32.1, “Basic Settings”.
kdumpas well as to enable or disable starting the service at boot time. When you are done, click to save the changes. The system reboot will be requested, and unless you are already authenticated, you will be prompted to enter the superuser password.
kdumpgui_run_bootloaderBoolean must be enabled before launching the Kernel Dump Configuration utility. This Boolean allows
system-config-kdumpto run the boot loader in the
bootloader_tSELinux domain. To permanently enable the Boolean, run the following command as
setsebool -P kdumpgui_run_bootloader 1
Enabling the Service
kdumpdaemon at boot time, click the button on the toolbar. This will enable the service for runlevels
5, and start it for the current session. Similarly, clicking the button will disable it for all runlevels and stop the service immediately.
The Basic Settings Tab
kdumpkernel. To do so, select the Manual kdump memory settings radio button, and click the up and down arrow buttons next to the New kdump Memory field to increase or decrease the value. Notice that the Usable Memory field changes accordingly showing you the remaining memory that will be available to the system.
Figure 32.1. Basic Settings
kdumpcrash 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). The memory can be attempted up to the maximum of 896 MB if required. This is recommended especially in large environments, for example in systems with a large number of Logical Unit Numbers (LUNs).
The Target Settings Tab
vmcoredump. It can be either stored as a file in a local file system, written directly to a device, or sent over a network using the NFS (Network File System) or SSH (Secure Shell) protocol.
Figure 32.2. Target Settings
/etc/dasd.conffile with other DASDs, for example:
0.0.2098 0.0.2198 0.0.2298 0.0.2398
0.0.2398are the DASDs used as the kdump target.
/etc/zfcp.conffile with other FCP-Attached SCSI disks, for example:
0.0.3d0c 0x500507630508c1ae 0x402424aa00000000 0.0.3d0c 0x500507630508c1ae 0x402424ab00000000 0.0.3d0c 0x500507630508c1ae 0x402424ac00000000
0.0.3d0c 0x500507630508c1ae 0x402424ab00000000and
0.0.3d0c 0x500507630508c1ae 0x402424ac00000000are the FCP-attached SCSI disks used as the kdump target.
vmcore.flatfile in the
/var/crash/directory on the target system, which is unreadable by the crash utility. To convert
vmcore.flatto a dump file that is readable by crash, run the following command as root on the target system:
~]# /usr/sbin/makedumpfile -R */tmp/vmcore-rearranged* < *vmcore.flat*
Table 32.1. Supported kdump targets
|Type||Supported Targets||Unsupported Targets|
|Raw device||All locally attached raw disks and partitions.||—|
|Local file system|| || Any local file system not explicitly listed as supported in this table, including the |
|Remote directory|| Remote directories accessed using the || Remote directories on the |
| Remote directories accessed using the || Remote directories accessed using the |
|Multipath-based storages.[a]|| Remote directories accessed using the |
|—|| Remote directories accessed over |
| Remote directories accessed using the |
| Remote directories accessed using the |
|Remote directories accessed using wireless network interfaces.|
[a] Supported in Red Hat Enterprise Linux 6 from kexec-tools-2.0.0-245.el6 onwards.
The Filtering Settings Tab
Figure 32.3. Filtering Settings
The Expert Settings Tab
Figure 32.4. Expert Settings
kdumpfails to create a core dump, select an appropriate option from the Default action pulldown list. Available options are (the default action), (to reboot the system), (to present a user with an interactive shell prompt), (to halt the system), and (to power the system off).
makedumpfilecore collector, edit the Core collector text field; see the section called “Configuring the Core Collector” for more information.