Way to start ubuntu instead of initramfs?

[0xorial]

I am in the situation now that whenever system boots it is in initramfs, so I have to do cryptsetup luksOpen /dev/sda3 sda3_crypt every time on boot. is there a way to avoid this? Installing ubuntu with "LVM with encryption" makes it just ask the password. Any idea how it works?

[pio2398]

I know that this comment is old, but nevertheless, this guide is likely one of the best (without any extra not needed steps).
For me work:
Create file /etc/crypttab with:
sda_3_crypt (replace with some used during install ) UUID=(UUID of FS) none luks
example:
root UUID=b473bcfe-8d2b-49a1-a931-a3d472ab1655 none luks

and run:
update-initramfs -u -k all

Maybe this will be useful for someone.