#StackBounty: #arch-linux #grub2 #manjaro #luks #ssd How should I enable discard and no workqueue for LUKS in Arch/Manjaro

Bounty: 200

So I’ve read the wiki and this answer, and I’m still a bit overwhelmed. In the wiki it feels like a lot of these are optional.

Here’s what I did. I used Manjaro to install into a single partition, which I may be regretting, and I enabled full disk encryption. What I observe when booting, to either windows or Linux, is I’m prompted for a password, and then I see the actual grub menu.

I’m not then certain which options will work. I think that LVM is enabled, but not 100% and I’m sure I selected ext4. I looked at modifying the grub.conf generation scripts, but I’m not sure where, nor am I sure if that’s the right place.

What’s the right answer for adding discard, no_read_workqueue, and no_write_workqueue on Manjaro?


here’s what my most current configuration is, but I keep getting dropped into a rescue shell. I’m trying to used the systemd cryptsetup to do all the things, which seems to suggest that I use luks.* parameters.

note: the name root is coming from my manual mounting in the rescue shell.

NAME        MAJ:MIN RM   SIZE RO TYPE  MOUNTPOINTS                                MOUNTPOINT                                 UUID
loop0         7:0    0 450.2M  1 loop  /var/lib/snapd/snap/wickrme/543            /var/lib/snapd/snap/wickrme/543            
loop1         7:1    0  55.4M  1 loop  /var/lib/snapd/snap/core18/2074            /var/lib/snapd/snap/core18/2074            
loop2         7:2    0  65.1M  1 loop  /var/lib/snapd/snap/gtk-common-themes/1515 /var/lib/snapd/snap/gtk-common-themes/1515 
loop3         7:3    0  32.3M  1 loop  /var/lib/snapd/snap/snapd/12398            /var/lib/snapd/snap/snapd/12398            
zram0       253:0    0   1.5G  0 disk  [SWAP]                                     [SWAP]                                     
nvme0n1     259:0    0 953.9G  0 disk                                                                                        
├─nvme0n1p1 259:1    0   100M  0 part  /boot/efi                                  /boot/efi                                  6CEB-F417
├─nvme0n1p2 259:2    0    16M  0 part                                                                                        
├─nvme0n1p3 259:3    0 780.6G  0 part                                                                                        
├─nvme0n1p4 259:4    0   508M  0 part                                                                                        CA343C30343C223D
├─nvme0n1p5 259:5    0 146.5G  0 part                                                                                        74c51543-eb14-4f61-afeb-b5de6c10a32a
│ └─root    254:0    0 146.5G  0 crypt /                                          /                                          e0a93c98-88a8-4fc9-9948-acdb423d05fd
└─nvme0n1p6 259:6    0  18.6G  0 part  [SWAP]                                     [SWAP]                                     72db96da-87e4-4b17-a622-6a4d56b314c6
4 ❯ cryptsetup luksDump /dev/nvme0n1p5                                                                                                                                                                         # ~
LUKS header information for /dev/nvme0n1p5

Version:        1
Cipher name:    aes
Cipher mode:    xts-plain64
Hash spec:      sha256
Payload offset: 4096
MK bits:        512
UUID:           74c51543-eb14-4f61-afeb-b5de6c10a32a
❯ cat /etc/default/grub | grep -v -e '^[[:space:]]*$' -e '^#'                                                                                                                                                  # ~
GRUB_CMDLINE_LINUX_DEFAULT="quiet luks.uuid=74c51543-eb14-4f61-afeb-b5de6c10a32a luks.options=discard,no_read_workqueue,no_write_workqueue root=/dev/mapper/luks-e0a93c98-88a8-4fc9-9948-acdb423d05fd splash apparmor=1 security=apparmor udev.log_priority=3"
GRUB_PRELOAD_MODULES="part_gpt part_msdos"

from what I understand systemd-cryptsetup-generator shouldn’t need more options, I do have an /etc/crypttab but everything is commented out.

I’m fairly confident that GRUB_CMDLINE_LINUX_DEFAULT is my only problem, I’m not certain what it should be though. google isn’t finding me a lot of (read no) examples of how to do this with the output of blkid or lsblk.

Get this bounty!!!

Leave a Reply

This site uses Akismet to reduce spam. Learn how your comment data is processed.