This section describes the tasks for managing crash dump procedures for your system.
Keep the following points in mind when you are working with system crash information:
You must assume the root role to access and manage system crash information. For more information, see Using Your Assigned Administrative Rights in Securing Users and Processes in Oracle Solaris 11.4.
Starting with the Oracle Solaris 11.3 release, when a system crashes, a copy of its physical memory is held in the RAM until the system reboots, then is written to the file system. This process is called a deferred dump. If a deferred dump is not possible, the physical memory is written to a dump device during a crash. For more information, see Crash Files Deferred Until After Reboot in Oracle Solaris 11.3 in Troubleshooting System Administration Issues in Oracle Solaris 11.4.
Do not disable the option of saving system crash dump files on the system. System crash dump files provide an invaluable way to determine what is causing the system to crash.
Dedicated ZFS volumes are used for swap and dump areas. For instructions, see Managing ZFS Swap and Dump Devices in Managing ZFS File Systems in Oracle Solaris 11.4.
For more information about managing system crash dump, see dumpadm(8) man page.
To display the current crash dump configuration, assume the root role and issue the dumpadm command with no arguments.
$ dumpadm Dump content: kernel with ZFS metadata Dump device: /dev/zvol/dsk/rpool/dump (dedicated) Savecore directory: /var/crash Savecore enabled: yes Save compressed: on
This example output shows the following configuration:
The dump content is kernel memory pages with ZFS metadata
Kernel memory will either be held in memory until a reboot or dumped on a dedicated dump device, /dev/zvol/dsk/rpool/dump
System crash dump files will be saved in the /var/crash directory
Saving crash dump files is enabled
Crash dump files are saved in compressed format
To modify the crash dump configuration, assume the root role and use the dumpadm command. Depending on the kernel memory and other internal information, the dumpadm command establishes a dump device to accommodate a dump file. The size of the dump device should be big enough to store the dump file, otherwise dumpadm displays an error message and the operation fails. For more information about managing the configuration of crash dumps using dumpadm, see the dumpadm(8) man page.
Example 1 Modifying a Crash Dump ConfigurationIn this example, all memory is dumped to the dedicated dump device, /dev/zvol/dsk/rpool/dump. 10% of the file system space must be available as minimum free space after the crash dump files are saved.
$ dumpadm Dump content: kernel with ZFS metadata Dump device: /dev/zvol/dsk/rpool/dump (dedicated) Savecore directory: /var/crash Savecore enabled: yes Save compressed: on $ dumpadm -c all -d /dev/zvol/dsk/rpool/dump -m 10% Dump content: all pages Dump device: /dev/zvol/dsk/rpool/dump (dedicated) Savecore directory: /var/crash (minfree = 5935131KB) Savecore enabled: yes Save compressed: on $ dumpadm -n Dump content: all pages Dump device: /dev/zvol/dsk/rpool/dump (dedicated) Savecore directory: /var/crash (minfree = 5935131KB) Savecore enabled: no Save compressed: on $ dumpadm -y Dump content: all pages Dump device: /dev/zvol/dsk/rpool/dump(dedicated) Savecore directory: /var/crash (minfree = 5935131KB) Savecore enabled: yes Save compressed: onExample 2 Disabling the Saving of Crash Dumps
This example shows how to disable the saving of crash dumps on your system.
$ dumpadm -n Dump content: all pages Dump device: /dev/zvol/dsk/rpool/dump (dedicated) Savecore directory: /var/crash (minfree = 5697105KB) Savecore enabled: no Save compressed: on
Caution - Do not disable the saving of crash dumps. Crash dumps provide a way to determine what causes your system to crash. |
This example shows how to enable the saving of crash dumps on your system.
$ dumpadm -y Dump content: all pages Dump device: /dev/zvol/dsk/rpool/dump (dedicated) Savecore directory: /var/crash (minfree = 5697105KB) Savecore enabled: yes Save compressed: on
The following table describes the differences between various dump devices. Note these differences when you set up a dump device.
|
The estimate provided by the dumpadm -e command depends on the currently running system and dump configuration. Therefore, you should run this command once your system is properly warmed up and the final dump configuration is in place. Otherwise the estimate might be wrong by a large margin.
For more information about the none dump device and the nodump attribute, see the ai_manifest(5) man page.