The dumpconf service

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The dumpconf service configures the action to be taken if a kernel panic or PSW restart occur.

The service is installed as a systemd unit and reads the configuration file /etc/sysconfig/dumpconf.
Note: kdump does not depend on dumpconf and can neither be enabled nor disabled with dumpconf. If kdump has been set up for your production system, dump tools as configured with dumpconf are used only if the integrity check for kdump fails. With kdump set up, you can use dumpconf to enable or disable backup dump tools. See also Failure recovery and backup tools.

dumpconf systemd service syntax


1  systemctl
1 start
1 stop
1 status
2  dumpconf

Parameters

start
enables the configuration that is defined in /etc/sysconfig/dumpconf.
stop
stops the dumpconf service.
status
shows current configuration status of the dumpconf service.

Keywords for the configuration file

ON_PANIC
Shutdown action to be taken if a kernel panic or PSW restart occur. Possible values are:
dump
Dump Linux® and stop system.
reipl
Reboot Linux.
dump_reipl
Dump Linux and reboot system.
vmcmd
Execute specified CP commands and stop system.
stop
Stop Linux (default).
DELAY_MINUTES
The number of minutes that the activation of dumpconf is to be delayed. The default is zero.

Using reipl or dump_reipl actions with ON_PANIC can lead to the system looping with alternating IPLs and crashes. Use DELAY_MINUTES to prevent such a loop. DELAY_MINUTES delays activating the specified panic action for a newly started system. When the specified time has elapsed, dumpconf activates the specified panic action. This action is taken should the system subsequently crash. If the system crashes before the time has elapsed, the previously defined action is taken. If no previous action has been defined, the default action (STOP) is performed.

VMCMD_<X>
Specifies a CP command, <X> is a number from one to eight. You can specify up to eight CP commands that are executed in case of a kernel panic or PSW restart. z/VM® commands, device addresses, and names of z/VM guest virtual machines must be uppercase.
DUMP_TYPE
Type of dump device. Possible values are ccw, eckd, fcp, and nvme.
DEVICE
specifies the device bus-ID for CCW or SCSI dump device.
WWPN
WWPN for SCSI disk.
LUN
LUN for SCSI disk.
FID
Function ID for NVMe dump device.
NSID
Name space ID for NVMe dump device.
BOOTPROG
Boot program selector
BR_CHR
Specifies the cylinder, head, and record of the boot record location as comma separated values, br_chr <c>,<h>,<r>. Alternatively, specifying auto makes the bootloader determine the boot record location. This is the default.
BR_LBA
Boot record logical block address.

Example configuration files for the dumpconf service

  • Example configuration for a CCW dump device (DASD) using reipl after dump and DELAY_MINUTES: 
    ON_PANIC=dump_reipl
DUMP_TYPE=ccw
DEVICE=0.0.4714
DELAY_MINUTES=5
  • Example configuration for a list-directed dump to an ECKD DASD dump device: 
    ON_PANIC=dump
DUMP_TYPE=eckd
DEVICE=0.0.1004
BOOTPROG=0
BR_CHR=auto
  • Example configuration for FCP dump device (SCSI disk): 
    ON_PANIC=dump
DUMP_TYPE=fcp
DEVICE=0.0.4711
WWPN=0x4712076300ce93a7
LUN=0x4712000000000000
BOOTPROG=0
BR_LBA=0
  • Example configuration for an NVMe dump device (NVMe disk): 
    ON_PANIC=dump
DUMP_TYPE=nvme
FID=0x00000001
NSID=0x00000001
BOOTPROG=0
BR_LBA=0
  • Example configuration for re-IPL if a kernel panic or PSW restart occurs: 
    ON_PANIC=reipl
  • Example of sending a message to the z/VM guest virtual machine "OPERATOR", executing a CP VMDUMP command, and rebooting from device 4711 if a kernel panic or PSW restart occurs: 
    ON_PANIC=vmcmd
VMCMD_1="MSG OPERATOR Starting VMDUMP"
VMCMD_2="VMDUMP"
VMCMD_3="IPL 4711"
    z/VM commands, device addresses, and names of z/VM guest virtual machines must be uppercase.

Examples for using the dumpconf service

Use the dumpconf service to enable and disable the configuration.
  • To enable the configuration: 
    # systemctl start dumpconf
  • To display the status: 
    # systemctl status dumpconf 
| dumpconf.service - Configure dump on panic 
   Loaded: loaded (/usr/lib/systemd/system/dumpconf.service...
   Active: active (exited) since Mon 2017-11-06 20:47:15 CET; 1s ago
   Process: 12200 ExecStart=/lib/s390-tools/dumpconf start (code=exited, status=0/SUCCESS
 Main PID: 12200 (code=exited, status=0/SUCCESS)

Nov 06 20:47:15 s3545002 systemd[1]: Starting Configure dump on panic ...
Nov 06 20:47:15 s3545002 dumpconf[12200]: dump_reipl on panic configured: Using ccw...
Nov 06 20:47:15 s3545002 systemd[1]: Started Configure dump on panic ...
  • To disable dump on panic: 
    # systemctl stop dumpconf
  • To display the status again and check that the status is now stopped:
    # systemctl status dumpconf
| dumpconf.service - Configure dump on panic
   Loaded: loaded (/usr/lib/systemd/system/dumpconf.service...
   Active: inactive (dead)
...
Nov 06 20:49:33 s3545002 systemd[1]: Stopping Configure dump on panic ...
Nov 06 20:49:33 s3545002 dumpconf[12217]: Dump on panic is disabled now
Nov 06 20:49:33 s3545002 systemd[1]: Stopped Configure dump on panic ...