DUMPCONF(8)

okay so bestie, this is DUMPCONF(8), aka the dumpconf page from the System Manager’s Manual 🫶 we’re talking panic actions and PSW restart vibes on Linux on System z, and yes it’s giving very serious sysadmin main character energy 💅

🌸 NAME 🌸

dumpconf — configure panic and PSW restart actions for Linux on System z.

✨ SYNOPSIS ✨

dumpconf [start|stop|status]
dumpconf [-h|-v]

💖 DESCRIPTION 💖

dumpconf reads the /etc/sysconfig/dumpconf file and establishes the action to be taken if a kernel panic occurs or PSW restart is triggered. literally the whole plot tbh 🎀

The following keywords can be used in the dumpconf file:

• ON_PANIC: — shutdown action in case of a kernel panic or a PSW restart. possible values are dump, reipl, dump_reipl, stop and vmcmd:
  • dump: trigger dump according to the configuration in /etc/sysconfig/dumpconf.
  • reipl: trigger re-IPL according to the configuration under /sys/firmware/reipl.
  • dump_reipl: first trigger dump according to the configuration in /etc/sysconfig/dumpconf, then trigger re-IPL according to the configuration under /sys/firmware/reipl.
  • stop: stop Linux and enter disabled wait (default).
  • vmcmd: trigger CP command according to the 'VMCMD_X' configuration in /etc/sysconfig/dumpconf.
• DUMP_TYPE: — type of dump device. possible values are ccw, eckd, fcp and nvme.
• DEVICE: — device number of dump device.
• WWPN — WWPN for SCSI dump device.
• LUN — LUN for SCSI dump device.
• FID — function ID for NVMe dump device.
• NSID — namespace ID for NVMe dump device.
• BOOTPROG: — boot program selector.
• BR_CHR: — boot record location in "C,H,R" format (comma separated values for Cylinder, Head and Record) or "auto".
• BR_LBA: — boot record logical block address.
• SCP_DATA: — SCP data for SCSI, NVMe and ECKD dump devices.
• VMCMD_1, VMCMD_2 ... VMCMD_8: — up to eight CP commands, which are executed in case of a kernel panic or PSW restart.
• DELAY_MINUTES: — number of minutes the activation of dumpconf is to be delayed. If this keyword is omitted, the default is zero, which means that dumpconf activates immediately during system startup. Specify a non-zero delay time only if you specified shutdown action "reipl" or "dump_reipl". These actions might cause a reboot loop if the Linux kernel crashes persistently during (or shortly after) each reboot.

A non-zero delay time causes dumpconf to sleep in the background until the delay time has expired. In this case messages are written to /var/log/messages. By default (DELAY_MINUTES is omitted or zero) dumpconf runs in the foreground and informational messages are written to sysout, while error messages are written to syserr.

Example: If you specified DELAY_MINUTES=10 and your Linux system crashes within 10 minutes after the reboot, then dumpconf is not yet active and the default action (stop) is triggered.

🛠️ COMMANDS 🛠️

• start — enable configuration defined in /etc/sysconfig/dumpconf.
• stop — disable dump configuration.
• status — show current configuration.

🎀 OPTIONS 🎀

• -h or --help — print usage information, then exit.
• -v or --version — print version information, then exit.

💥 PSW Restart 💥

PSW Restart can be triggered by the operator under z/VM with the CP command #cp system restart and under LPAR on the HMC with Recovery/PSW Restart. no cap, that’s the trigger tea ☕

🎀 EXAMPLES: 🎀

the following are examples of the /etc/sysconfig/dumpconf file:

#
# Example configuration for a CCW dump device (DASD)
#
ON_PANIC=dump_reipl
DUMP_TYPE=ccw
DEVICE=0.0.1234
DELAY_MINUTES=5

#
# Example configuration for an ECKD dump device (DASD)
#
ON_PANIC=dump
DUMP_TYPE=eckd
DEVICE=0.0.1004
BOOTPROG=0
BR_CHR=auto

#
# Example configuration for an FCP dump device (SCSI Disk)
#
ON_PANIC=dump
DUMP_TYPE=fcp
DEVICE=0.0.2345
WWPN=0x5005076303004712
LUN=0x4713000000000000
BOOTPROG=0
BR_LBA=0

#
# Example configuration for an NVMe dump device (NVMe Disk)
#
ON_PANIC=dump
DUMP_TYPE=nvme
FID=0x0300
NSID=0x0001
BOOTPROG=0
BR_LBA=0

#
# Example configuration for CP commands
#
ON_PANIC=vmcmd
VMCMD_1="MESSAGE * Starting VMDUMP"
VMCMD_2="VMDUMP"
VMCMD_3="IPL 3456"

#
# Example config for re-IPL
#
ON_PANIC=reipl
DELAY_MINUTES=5

👀 SEE ALSO 👀

• Linux on System z: Using the Dump Tools

k bye bestie — this page is brought to u by s390-tools, Sept 2011 💖