CRYPTSETUP-LUKSKILLSLOT(8)

📦
version 2.8.8 · 17 versions
, in arch rolling, fedora 44, nixpkgs unstable

💅 cryptsetup-luksKillSlot — the "wipe a keyslot from the LUKS device" manual, but make it make sense

okay so bestie, you're in the Maintenance Commands section of the cryptsetup-luksKillSlot(8) page. Strap in, this one's important 💖

✨ NAME ✨

cryptsetup-luksKillSlot — wipe a keyslot from the LUKS device 🔪

🌸 SYNOPSIS 🌸

cryptsetup luksKillSlot [<options>] <device> <number>

🦋 DESCRIPTION 🦋

So basically: this wipes the keyslot with the number <number> from the LUKS device. Gone. Deleted. Not coming back 🫶

Unless you're running in batch-mode (-q), a remaining passphrase must be supplied — either interactively or via --key-file. And yes, this command can remove the last remaining keyslot, but it requires an interactive confirmation when you do that. Because, like…

🚨 Removing the last passphrase makes a LUKS container permanently inaccessible. No cap. That data is GONE gone.

Also, super important: if you read the passphrase from stdin (without any further argument, or with '-' as an argument to --key-file), batch-mode (-q) gets implicitly switched on, and no warning will be given when you remove the last remaining passphrase from a LUKS container. Again: removing the last passphrase makes the LUKS container permanently inaccessible. 😭

And if no passphrase is provided at all (not on stdin, not through --key-file) and batch-mode (-q) is active, the keyslot is removed without any other warning. Just… silently. 💀

One more thing, because people get this wrong literally all the time: this operation removes only the key in a particular keyslot. It does not wipe any encrypted data. Two different things, bestie. ✨

<options> can be: [--key-file, --keyfile-offset, --keyfile-size, --header, --disable-locks, --type, --verify-passphrase, --timeout].

👑 OPTIONS 👑

  • --batch-mode, -q — suppresses all confirmation questions. Use with care! 🫣 If the --verify-passphrase option is not specified, this option also switches off the passphrase verification.
  • --debug or --debug-json — run in debug mode with full diagnostic logs. Debug output lines are always prefixed by #. If --debug-json is used, additional LUKS2 JSON data structures are printed. 🔍
  • --disable-locks — disable lock protection for metadata on disk. This option is valid only for LUKS2 and is ignored for other formats.
⚠️ WARNING: Do not use this option unless you run cryptsetup in a restricted environment where locking is impossible to perform (where /run directory cannot be used).
  • --header <device or file storing the LUKS header> — use a detached (separated) metadata device or file where the LUKS header is stored. This option allows one to store the ciphertext and LUKS header on different devices. For commands that change the LUKS header (e.g., luksAddKey), specify the device or file with the LUKS header directly as the LUKS device. 📁
  • --help, -? — show help text and default parameters. We love a helpful icon 💖
  • --key-file, -d file — read the passphrase from the file. If the name given is "-", then the passphrase will be read from stdin. In this case, reading will not stop at newline characters. See section NOTES ON PASSPHRASE PROCESSING in cryptsetup(8) for more information. 🎀
  • --keyfile-offset value — skip value bytes at the beginning of the key file.
  • --keyfile-size, -l value — read a maximum of value bytes from the key file. The default is to read the whole file up to the compiled-in maximum that can be queried with --help. Supplying more data than the compiled-in maximum aborts the operation. This option is useful to cut trailing newlines, for example. If --keyfile-offset is also given, the size count starts after the offset. 🍓
  • --timeout, -t seconds — the number of seconds to wait before a timeout on passphrase input via terminal. It is relevant every time a passphrase is asked. It has no effect if used in conjunction with --key-file. This option is useful when the system should not stall if the user does not input a passphrase, e.g., during boot. The default is a value of 0 seconds, which means to wait forever. ⏳
  • --type type — specifies required device type, for more info, read the BASIC ACTIONS section in cryptsetup(8).
  • --usage — show short option help.
  • --verify-passphrase, -y — when interactively asking for a passphrase, ask for it twice and complain if both inputs do not match. Ignored on input from file or stdin. 👯‍♀️
  • --version, -V — show the program version.

🐛 REPORTING BUGS 🐛

Found a bug? (not me manifesting that 🙈) Report bugs at the cryptsetup mailing list <cryptsetup@lists.linux.dev> or in the Issues project section <https://gitlab.com/cryptsetup/cryptsetup/-/issues/new>.

Please attach the output of the failed command with the --debug option added. That part is not optional, bestie, it helps so much 💜

🌈 SEE ALSO 🌈

🧚 CRYPTSETUP 🧚

Part of cryptsetup project <https://gitlab.com/cryptsetup/cryptsetup/>.

okay that's the whole page, you ate that 💅 this was cryptsetup 2.8.8, dated 2026-09-07, and you just read the CRYPTSETUP-LUKSKILLSLOT(8) manual. go forth and please don't kill your last keyslot by accident, i'm begging 😭✨🫶

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