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Linux command

crypttab 命令

文本

复制后可按需替换文件名、目录或参数。

常用示例

View current crypttab

cat /etc/crypttab

Basic encrypted partition entry

luks_root UUID=[device-uuid] none luks

Entry with keyfile

luks_data UUID=[device-uuid] /root/keyfile luks

Entry with discard/TRIM support

luks_ssd UUID=[device-uuid] none luks,discard

Entry for swap encryption

cryptswap /dev/sdX /dev/urandom swap,cipher=aes-xts-plain64,size=256

说明

/etc/crypttab defines encrypted block devices to be unlocked at boot by systemd-cryptsetup or cryptsetup. Each line describes one encrypted device: its mapped name, source device, key material, and options. The file works alongside /etc/fstab: crypttab unlocks encrypted devices, then fstab mounts the resulting mapped devices. For LUKS devices, the system prompts for a password at boot unless a keyfile is specified. UUID-based device identification is recommended over device paths for reliability across hardware changes.

FAQ

What is the crypttab command used for?

/etc/crypttab defines encrypted block devices to be unlocked at boot by systemd-cryptsetup or cryptsetup. Each line describes one encrypted device: its mapped name, source device, key material, and options. The file works alongside /etc/fstab: crypttab unlocks encrypted devices, then fstab mounts the resulting mapped devices. For LUKS devices, the system prompts for a password at boot unless a keyfile is specified. UUID-based device identification is recommended over device paths for reliability across hardware changes.

How do I run a basic crypttab example?

Run `cat /etc/crypttab` in a terminal, then adjust file names, paths, flags, or remote targets for your system.

Where can I find more crypttab examples?

This page includes 5 examples for crypttab, plus related commands for nearby Linux tasks.