I have installed system on ext4 filesystem on lvm (vg name encrypted, root is called encrypted-root) on luks. When I'm trying to run fstrim /, I get fstrim: /: the discard operation is not supported.
My /etc/crypttab contains
cryptroot UUID=5ddb7e3a-dcbe-442d-85e8-359e944d0717 none luks,discard,lvm=encrypted
/etc/lvm/lvm.conf contains
issue_discards = 1
/etc/initramfs-tools/conf.d/cryptroot contains only
CRYPTROOT=target=encrypted-root,source=/dev/disk/by-uuid/5ddb7e3a-dcbe-442d-85e8-359e944d0717
(I used update-initramfs -k all -c to create initramfs).
/etc/default/grub contains
GRUB_CMDLINE_LINUX="cryptops=target=encrypted-root,source=/dev/disk/by-uuid/5ddb7e3a-dcbe-442d-85e8-359e944d0717,lvm=encrypted"
I have tried to manually put rd.luks.options=discard as parameter for linux in grub. I have tried refresh option of cryptsetup utility (cryptsetup --allow-discards refreshdevice), but it does not seem to have one (cryptsetup: Unknown action).
Physical device apparently has TRIM support, when I run fstrim /boot it works (it's same device, just not encrypted).
dmsetup table command does not show allow_discards for cryptroot.
When I boot from USB and manually decrypt (with --allow-discards argument to cryptsetup) and mount root partition, it works. I have tried to use --persistent option, but it said that it couldn't make it persistent.
I'm lost. What should I do to make fstrim / work? Something tells me I should somehow modify boot options in grub, but I'm not sure how. I'm also not sure if line in /etc/crypttab is used at all (I changed it to cryptroot after install, it seems to do nothing even if I change it).
I'm running Linux Mint 19.3.
Links:
- I have followed this guide to encrypt system: link
- Arch-wiki section about SSDs and dm-crypt
- possibly relevant: 1, 2
