KDUMPCTL(8)

💖 NAME 💖

kdumpctl — control interface for kdump 💅

okay so bestie, this is a page from the System Manager's Manual (that's section 8, the big-girl system administration one), and it's literally just "I control kdump, and I'm not sorry about it." 🎀

---

🎀 SYNOPSIS 🎀

kdumpctl COMMAND

---

✨ DESCRIPTION ✨

so kdumpctl is the check-or-control bestie for the kdump service. 🫶

but ngl? in most cases you should use systemctl to start / stop / enable the kdump service instead. like, that's the normal way, fr fr.

kdumpctl is still here though, giving you more details for debugging and a cute little helper to set up ssh key authentication. it's giving ✨tool for when things get real✨. iconic behaviour, honestly.

---

👑 COMMANDS 👑

• start — starts the service. simple, clean, slay. ✨
• stop — stops the service. ✋
• status — prints the current status of kdump service. it returns a non-zero value if kdump is not operational, so watch that exit code like it's your situationship. 💀
• restart — is equal to start; stop. that's it, that's the whole personality. 🔁
• reload — reload the crash kernel image and initramfs without triggering a rebuild. no rebuild, no drama, just vibes. 💅
• rebuild — rebuild the crash kernel initramfs. 🛠️
• propagate — helps to setup key authentication for ssh storage, since it's impossible to use password authentication during kdump. like, genuinely impossible, so we do keys instead. 🔑✨
• showmem — prints the size of reserved memory for the crash kernel, in megabytes. 🧮
• estimate — estimate a suitable crashkernel value for the current machine. this is a best-effort estimate. it will print a recommended crashkernel value based on the current kdump setup, and list some details of memory usage. 🫶
• get-default-crashkernel — return the default crashkernel value provided by kdump-utils. here's your default, babes. 🎁
• reset-crashkernel [--kernel=path_to_kernel] — reset crashkernel to the default value recommended by kdump-utils. if no kernel is specified, will reset KDUMP_KERNELVER if it's defined in /etc/sysconfig/kdump, or the current running kernel's crashkernel value if KDUMP_KERNELVER is empty.

you can also specify --kernel=ALL and --kernel=DEFAULT, which have the same meaning as grubby's kernel-path=ALL and kernel-path=DEFAULT. 👑

ppc64le supports FADump and supports an additional [--fadump=[on|off|nocma]] parameter to toggle FADump on/off. 🌸

Note: The memory requirements for kdump varies heavily depending on the used hardware and system configuration. Thus the recommended crashkernel might not work for your specific setup. Please test if kdump works after resetting the crashkernel value. ⚠️

• test [--force] — test the kdump by actually trigger the system crash & dump, and check if a vmcore can really be generated successfully based on current config and environment. after system reboot back to normal, check the test result by "kdumpctl status". note, fadump is not supported. 😭

if the optional parameter [--force] is provided, there will be no confirmation before triggering the system crash. dangerous though — this option is meant for automation testing. 💀🔥

• setup-crypttab — add the 'link-volume-key' option to /etc/crypttab so vmcore can be saved to LUKS-encrypted disk volume. for more info on link-volume-key option, please "man crypttab". 🔐

this step is optional. if kdump.service can start successfully, there is no need for this step. you can confirm if this step is needed by running "kdumpctl restart". if you need to input any passpharse to unlock the the encrypted volume, then please run "kdumpctl setup-crypttab". 🗝️

Note: this subcommand is only helpful to x86_64 for now. 🙈

---

🦋 SEE ALSO 🦋

kdump.conf(5), mkdumprd(8)

go read those too, bestie, they're right there. 🫶

---

and that's the whole page, periodt. 💅 this cutie came from kdump-utils, dated 2015-07-13 — still serving looks all these years later. 🌈👑 stay safe out there, and don't --force a system crash without meaning it, fr fr. 🎀✨