Questions tagged [cryptsetup]

cryptsetup is a command-line utility for managing disk volumes encrypted using the dm-crypt kernel subsystem (Linux versions 2.6 up and DragonFly BSD).

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How can I shrink a LUKS partition, what does `cryptsetup resize` do?

I am in progress of resizing a LUKS encrypted partition that contains a single ext4 filesystem (no LVM or something). The cryptsetup FAQ recommends to remove the old partition and recreate it, but ...
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15 votes
1 answer
10k views

What does `cryptsetup resize` do if LUKS doesn't store partition size?

The LUKS / dm-crypt / cryptsetup FAQ page says: 2.15 Can I resize a dm-crypt or LUKS partition? Yes, you can, as neither dm-crypt nor LUKS stores partition size. I'm befuzzled: What is "...
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37 votes
3 answers
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Using a single passphrase to unlock multiple encrypted disks at boot

My machine has an SSD, where I installed the system and an HDD, which I use as a storage for large and/or infrequently used files. Both are encrypted, but I chose to use the same passphrase for them. ...
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26 votes
3 answers
82k views

Why my encrypted LVM volume (LUKS device) won't mount at boot time?

I'm trying to setup an encrypted volume following this guide Everything is setup but mounting the encrypted volume fails at boot-time with the error: fsck.ext4: No such file or directory while ...
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23 votes
5 answers
12k views

How can I set a label on a dm-crypt+LUKS container?

I just received a new USB flash drive, and set up 2 encrypted partitions on it. I used dm-crypt (LUKS mode) through cryptsetup. With an additional non-encrypted partition, the drive has the following ...
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8 votes
1 answer
7k views

LUKS storing keyfile in encrypted usb drive

I already asked once about LUKS unlocking of multiple HDDs in Linux: LUKS and multiple hard drives. Now I would like to know how to secure store the keyfile used for the automatic unlock of the ...
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4 votes
3 answers
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How much storage overhead comes along with cryptsetup and ext4?

I want to encrypt the content of a directory in a container with an ext4 filesystem using cryptsetup. The size of the container should be as small as possible and as big as necessary, because I only ...
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24 votes
1 answer
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Abysmal general dm-crypt (LUKS) write performance

I am investigating a problem where encrypting a block device imposes a huge performance penalty when writing to it. Hours of Internet reading and experiments did not provide me with a proper ...
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11 votes
5 answers
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Unlock LUKS encrypted Debian root with key file on boot partition

I'm trying to decrypt the Debian root with a key file stored in the boot partition (decrypted partition). This will break the security, but it doesn't matter now. I have to conclude this successfully ...
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  • 111
6 votes
2 answers
5k views

LUKS discard/TRIM: conflicting kernel command line options

I'm confused between the various ways that LUKS/dmcrypt/cryptsetup discard /TRIM operations can be enabled via the Linux kernel command line. The dracut manpage: rd.luks.allow-discards Allow ...
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6 votes
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remap read-only LUKS partition to read-write

cryptsetup can be invoked with --readonly or -r option, which will set up a read-only mapping: cryptsetup --readonly luksOpen /dev/sdb1 sdb1 Once I have opened a device as read-only, can I later re-...
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5 votes
1 answer
4k views

LUKS passphrase doesn't work

One day, when I turned on the computer, my passphrase for home part /dev/sda7 doesn't worked (I am 147% absolutely sure, that I was writing right pass)! After three times of tries, I have rebooted ...
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7 votes
3 answers
9k views

luksOpen doesn't decrypt with keyfile unless --key-file argument is provided

I have an encrypted volume for which I had initially set up a passphrase interactively, which works just fine to decrypt the partition. I added more keys using a keyfile in both the following ways: ...
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5 votes
1 answer
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Using space before 1st partition of USB-Stick as luks key

I'm using arch linux with an encrypted luks root partition (boot unencrypted), with a passphrase yet. Now I have a keyfile (3072 bytes), that's written to USB-Stick this way: sudo dd if=tempKeyFile....
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5 votes
1 answer
2k views

dmsetup luksFormat creating an alignment inconsistency

When unlocking a newly-formatted LUKS volume, I received a warning in the kernel log: kernel: device-mapper: table: 253:14: adding target device sdk1 caused an alignment inconsistency: ...
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4 votes
1 answer
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`cryptsetup luksOpen <device> <name>` fails to set up the specified name mapping

HardenedArray has a helpful archlinux-installation guide at Efficient Encrypted UEFI-Booting Arch Installation. However, I encountered difficulty early in the installation process -- specifically, at ...
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3 votes
0 answers
1k views

Automount encrypted disk on demand with systemd using interactive passphrase

I try to automount an LUKS encrypted disk with systemd on demand with in interactive passphrase. I am using a plain Debian without any window manager etc. I have configured crypttab and fstab "...
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1 answer
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ssh: connect to host raspberry port 22: No route to host

I can't log in into ssh to crypt luks encrypted device with installed dropbear but I can while rpi is decrypted. I'm getting error: ssh: connect to host raspberry port 22: No route to host. While ...
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3 votes
1 answer
4k views

Difference between cryptopts and crypttab

I'm setting up an encrypted root fs, which I've done before, but this time I'm using a PGP-encrypted keyfile with a symmetric password to familiarize myself with the process. There are two places ...
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1 vote
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How to ask for a password to mount crypted swap at boot time on Linux Mint 16 with initramfs-tools? [duplicate]

I use encrypted home folders on my notebook, which prevents use of hibernation on standard setup, because - and for a good reason - besides encrypting the home folder with ecryptfs, it reformats the ...
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1 vote
1 answer
404 views

No volume group in lvm2 disk? Want to mount a logical partition

How am I supposed to mount a logical volume from a decrypted drive, when the VG column is blank? The last time I could do it, (ubuntu-vg was showing), but now it has a blank name? root@debian:/home/...
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1 vote
1 answer
868 views

Storing a keyfile in an encrypted LVM

I'm using RHEL 6.5 and I want to encrypt some of my logical volumes (LVM). In order to not have to enter the passphrase multiple times, I want to store a keyfile in an encrypted LV. Example: /var/...
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0 votes
2 answers
869 views

crypttab: location of luks header file

Hi my crypttab looks as follows: crypt_device /dev/sda luks,header=/boot/header.img update-initramfs -u -k all works with success, but for some reason cryptsetup will not find the header.img which ...
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