CRYPTSETUP-REPAIR(8)

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

💖 CRYPTSETUP-REPAIR(8) 💖

okay so bestie, welcome to cryptsetup-repair(8) — yeah she's one of the Maintenance Commands, and she's literally the girl who shows up when your LUKS header is going through it. 🩹✨

🌸 NAME 🌸

cryptsetup-repair — repair the device metadata. that's it, that's the whole job. she fixes the metadata. 💅

🦋 SYNOPSIS 🦋

cryptsetup repair [<options>] <device>

✨ DESCRIPTION ✨

So basically: she tries to repair the device metadata if possible. rn that's only supported for LUKS device type, so don't come at her with anything else, she will not know her. 🙈

This command is lowkey a lifesaver for fixing some known benign LUKS metadata header corruptions. Heads up though: only basic corruptions of unused keyslot are fixable. And important — she will only change the LUKS header, not any keyslot data. not touching that. You can enforce the LUKS version by adding the --type option if you want to be specific about it.

She also repairs (upgrades) LUKS2 reencryption metadata by adding a metadata digest that protects it against malicious changes. protective queen. 👑

And if LUKS2 reencryption got interrupted while writing the reencryption segment, the repair command can perform reencryption recovery so that reencryption can continue later. Repairing reencryption requires verification of the reencryption keyslot, so a passphrase or keyfile is needed. no passphrase, no recovery, sorry babe. 😭

WARNING: Always create a binary backup of the original header before calling this command. fr fr. always. back it up first. 💀

🔍 LUKS keyslots corruption detection 🔍

The repair command also checks for detectable corruption of keyslot content. Why do we care? Because corruption of a keyslot results in a situation where a known password is no longer accepted — the worst kind of betrayal. 😭 This can happen due to storage media failure or overwriting the keyslot area with other data. Only certain corruptions can be detected, usually only a low-entropy area (like zeroed blocks).

The detection prints only warnings. It does not modify keyslots. It can also print more specific offsets on the device so you can go do detailed manual inspection if you're that girl. 🕵️‍♀️

Please note — and this is important, bestie — the warning can be a false positive (like, no real corruption happened, she's just being cautious). Conversely, if the keyslot is corrupted, no recovery is possible. You have to use the LUKS header backup. that's the whole point of the backup. periodt. 🎀

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

💅 OPTIONS 💅

  • --batch-mode, -q — Suppresses all confirmation questions. Use with care! And if the --verify-passphrase option is not specified, this option also switches off the passphrase verification. so like, she just goes. no asking. 🫣
  • --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. nerdy and I love her for it. 🤓
  • --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. keeping them separated, very independent of them. 💁‍♀️
  • --help, -? — Show help text and default parameters. always read the help first bestie, it's free. 📖
  • --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. just, like, hopping over the first bit. 🦘
  • --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. ✂️
  • --key-slot, -S <0-N> — For LUKS operations that add key material, this option allows you to specify which keyslot is selected for the new key. The maximum number of keyslots depends on the LUKS version. LUKS1 can have up to 8 keyslots. LUKS2 can have up to 32 keyslots based on keyslot area size and key size, but a valid keyslot ID can always be between 0 and 31 for LUKS2.
  • --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. (forever is a long time bestie ⏳)
  • --type type — Specifies required device type, for more info, read the BASIC ACTIONS section in cryptsetup(8).
  • --usage — Show short option help. the lil mini version. 🐣
  • --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. double-check queen. ✅
  • --version, -V — Show the program version.

🐛 REPORTING BUGS 🐛

Found a bug? Don't be shy, report it 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. receipts, bestie, always bring receipts. 🧾

👀 SEE ALSO 👀

🌈 CRYPTSETUP 🌈

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

okay that's the whole page bestie, go forth and back up your header first 💖✨ this was cryptsetup version 2.8.8, dated 2026-09-07 — slay, mwah, bye 🎀🦋

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