Luks Partition Mounting After Removing From fstab

Question

I have 3 encrypted partitions, one for /, one for /home, and one for swap.

It seemed silly to me to type in my password 3 times, so I replaced the swap partition with a swap file on the encrypted drive. However, even though I removed the entry from fstab, I am still being prompted for my password for the old swap partition on boot.

When I boot, the OS asks me for the password for sda7_crypt which I would expect. However, after that, it asks me for the password for sda5_crypt. How do I disable sda5_crypt?

/etc/fstab:

/dev/mapper/sda7_crypt       /     ext4 errors=remount-ro 0 1
UUID=xxxxxxxxxxxxxxxxxxxxxxx /boot ext4 defaults 0 2
/dev/mapper/sdb5_crypt       /home ext4 defaults 0 2
/myswapfile                  swap  swap defaults 0 0

/etc/cryptsetup:

sda7_crypt UUID=xxxxxxxxxxxxxxxxxxxxx none luks,discard 
sdb5_crypt UUID=xxxxxxxxxxxxxxxxxxxxx /keyfile luks,discard

---

---

Update: more information to answer questions in the comments:

System: Ubuntu 14.04 64-bit Desktop

/boot/grub/grub.cfg:

#
# DO NOT EDIT THIS FILE
#
# It is automatically generated by grub-mkconfig using templates
# from /etc/grub.d and settings from /etc/default/grub
#

### BEGIN /etc/grub.d/00_header ###
if [ -s $prefix/grubenv ]; then
  set have_grubenv=true
  load_env
fi
if [ "${next_entry}" ] ; then
   set default="${next_entry}"
   set next_entry=
   save_env next_entry
   set boot_once=true
else
   set default="0"
fi

if [ x"${feature_menuentry_id}" = xy ]; then
  menuentry_id_option="--id"
else
  menuentry_id_option=""
fi

export menuentry_id_option

if [ "${prev_saved_entry}" ]; then
  set saved_entry="${prev_saved_entry}"
  save_env saved_entry
  set prev_saved_entry=
  save_env prev_saved_entry
  set boot_once=true
fi

function savedefault {
  if [ -z "${boot_once}" ]; then
    saved_entry="${chosen}"
    save_env saved_entry
  fi
}
function recordfail {
  set recordfail=1
  if [ -n "${have_grubenv}" ]; then if [ -z "${boot_once}" ]; then save_env recordfail; fi; fi
}
function load_video {
  if [ x$feature_all_video_module = xy ]; then
    insmod all_video
  else
    insmod efi_gop
    insmod efi_uga
    insmod ieee1275_fb
    insmod vbe
    insmod vga
    insmod video_bochs
    insmod video_cirrus
  fi
}

if loadfont unicode ; then
  set gfxmode=auto
  load_video
  insmod gfxterm
  set locale_dir=$prefix/locale
  set lang=en_US
  insmod gettext
fi
terminal_output gfxterm
if [ "${recordfail}" = 1 ] ; then
  set timeout=-1
else
  if [ x$feature_timeout_style = xy ] ; then
    set timeout_style=hidden
    set timeout=0
  # Fallback hidden-timeout code in case the timeout_style feature is
  # unavailable.
  elif sleep --interruptible 0 ; then
    set timeout=0
  fi
fi
### END /etc/grub.d/00_header ###

### BEGIN /etc/grub.d/05_debian_theme ###
set menu_color_normal=white/black
set menu_color_highlight=black/light-gray
if background_color 44,0,30; then
  clear
fi
### END /etc/grub.d/05_debian_theme ###

### BEGIN /etc/grub.d/10_linux ###
function gfxmode {
    set gfxpayload="${1}"
    if [ "${1}" = "keep" ]; then
        set vt_handoff=vt.handoff=7
    else
        set vt_handoff=
    fi
}
if [ "${recordfail}" != 1 ]; then
  if [ -e ${prefix}/gfxblacklist.txt ]; then
    if hwmatch ${prefix}/gfxblacklist.txt 3; then
      if [ ${match} = 0 ]; then
        set linux_gfx_mode=keep
      else
        set linux_gfx_mode=text
      fi
    else
      set linux_gfx_mode=text
    fi
  else
    set linux_gfx_mode=keep
  fi
else
  set linux_gfx_mode=text
fi
export linux_gfx_mode
menuentry 'Ubuntu' --class ubuntu --class gnu-linux --class gnu --class os $menuentry_id_option 'gnulinux-simple-c3444e01-a00a-4e4b-a73e-d213dc913a1e' {
    recordfail
    load_video
    gfxmode $linux_gfx_mode
    insmod gzio
    insmod part_msdos
    insmod ext2
    set root='hd0,msdos6'
    if [ x$feature_platform_search_hint = xy ]; then
      search --no-floppy --fs-uuid --set=root --hint-bios=hd0,msdos6 --hint-efi=hd0,msdos6 --hint-baremetal=ahci0,msdos6  52381e81-2730-434f-93be-e8223c4aa95c
    else
      search --no-floppy --fs-uuid --set=root 52381e81-2730-434f-93be-e8223c4aa95c
    fi
    linux   /vmlinuz-3.13.0-35-generic root=UUID=xxxxxxxxxxxxxxxxxxxxxxx ro  quiet splash $vt_handoff
    initrd  /initrd.img-3.13.0-35-generic
}
submenu 'Advanced options for Ubuntu' $menuentry_id_option 'gnulinux-advanced-c3444e01-a00a-4e4b-a73e-d213dc913a1e' {
    menuentry 'Ubuntu, with Linux 3.13.0-35-generic' --class ubuntu --class gnu-linux --class gnu --class os $menuentry_id_option 'gnulinux-3.13.0-35-generic-advanced-c3444e01-a00a-4e4b-a73e-d213dc913a1e' {
        recordfail
        load_video
        gfxmode $linux_gfx_mode
        insmod gzio
        insmod part_msdos
        insmod ext2
        set root='hd0,msdos6'
        if [ x$feature_platform_search_hint = xy ]; then
          search --no-floppy --fs-uuid --set=root --hint-bios=hd0,msdos6 --hint-efi=hd0,msdos6 --hint-baremetal=ahci0,msdos6  52381e81-2730-434f-93be-e8223c4aa95c
        else
          search --no-floppy --fs-uuid --set=root 52381e81-2730-434f-93be-e8223c4aa95c
        fi
        echo    'Loading Linux 3.13.0-35-generic ...'
        linux   /vmlinuz-3.13.0-35-generic root=UUID=xxxxxxxxxxxxxxxx ro  quiet splash $vt_handoff
        echo    'Loading initial ramdisk ...'
        initrd  /initrd.img-3.13.0-35-generic
    }
    menuentry 'Ubuntu, with Linux 3.13.0-35-generic (recovery mode)' --class ubuntu --class gnu-linux --class gnu --class os $menuentry_id_option 'gnulinux-3.13.0-35-generic-recovery-c3444e01-a00a-4e4b-a73e-d213dc913a1e' {
        recordfail
        load_video
        insmod gzio
        insmod part_msdos
        insmod ext2
        set root='hd0,msdos6'
        if [ x$feature_platform_search_hint = xy ]; then
          search --no-floppy --fs-uuid --set=root --hint-bios=hd0,msdos6 --hint-efi=hd0,msdos6 --hint-baremetal=ahci0,msdos6  52381e81-2730-434f-93be-e8223c4aa95c
        else
          search --no-floppy --fs-uuid --set=root 52381e81-2730-434f-93be-e8223c4aa95c
        fi
        echo    'Loading Linux 3.13.0-35-generic ...'
        linux   /vmlinuz-3.13.0-35-generic root=UUID=c3444e01-a00a-4e4b-a73e-d213dc913a1e ro recovery nomodeset 
        echo    'Loading initial ramdisk ...'
        initrd  /initrd.img-3.13.0-35-generic
    }
    menuentry 'Ubuntu, with Linux 3.13.0-34-generic' --class ubuntu --class gnu-linux --class gnu --class os $menuentry_id_option 'gnulinux-3.13.0-34-generic-advanced-c3444e01-a00a-4e4b-a73e-d213dc913a1e' {
        recordfail
        load_video
        gfxmode $linux_gfx_mode
        insmod gzio
        insmod part_msdos
        insmod ext2
        set root='hd0,msdos6'
        if [ x$feature_platform_search_hint = xy ]; then
          search --no-floppy --fs-uuid --set=root --hint-bios=hd0,msdos6 --hint-efi=hd0,msdos6 --hint-baremetal=ahci0,msdos6  52381e81-2730-434f-93be-e8223c4aa95c
        else
          search --no-floppy --fs-uuid --set=root 52381e81-2730-434f-93be-e8223c4aa95c
        fi
        echo    'Loading Linux 3.13.0-34-generic ...'
        linux   /vmlinuz-3.13.0-34-generic root=UUID=xxxxxxxxxxxxxxxxx ro  quiet splash $vt_handoff
        echo    'Loading initial ramdisk ...'
        initrd  /initrd.img-3.13.0-34-generic
    }
    menuentry 'Ubuntu, with Linux 3.13.0-34-generic (recovery mode)' --class ubuntu --class gnu-linux --class gnu --class os $menuentry_id_option 'gnulinux-3.13.0-34-generic-recovery-c3444e01-a00a-4e4b-a73e-d213dc913a1e' {
        recordfail
        load_video
        insmod gzio
        insmod part_msdos
        insmod ext2
        set root='hd0,msdos6'
        if [ x$feature_platform_search_hint = xy ]; then
          search --no-floppy --fs-uuid --set=root --hint-bios=hd0,msdos6 --hint-efi=hd0,msdos6 --hint-baremetal=ahci0,msdos6  52381e81-2730-434f-93be-e8223c4aa95c
        else
          search --no-floppy --fs-uuid --set=root 52381e81-2730-434f-93be-e8223c4aa95c
        fi
        echo    'Loading Linux 3.13.0-34-generic ...'
        linux   /vmlinuz-3.13.0-34-generic root=UUID=xxxxxxxxxxxxxxxxxxxxxxxxx ro recovery nomodeset 
        echo    'Loading initial ramdisk ...'
        initrd  /initrd.img-3.13.0-34-generic
    }
    menuentry 'Ubuntu, with Linux 3.13.0-33-generic' --class ubuntu --class gnu-linux --class gnu --class os $menuentry_id_option 'gnulinux-3.13.0-33-generic-advanced-c3444e01-a00a-4e4b-a73e-d213dc913a1e' {
        recordfail
        load_video
        gfxmode $linux_gfx_mode
        insmod gzio
        insmod part_msdos
        insmod ext2
        set root='hd0,msdos6'
        if [ x$feature_platform_search_hint = xy ]; then
          search --no-floppy --fs-uuid --set=root --hint-bios=hd0,msdos6 --hint-efi=hd0,msdos6 --hint-baremetal=ahci0,msdos6  52381e81-2730-434f-93be-e8223c4aa95c
        else
          search --no-floppy --fs-uuid --set=root 52381e81-2730-434f-93be-e8223c4aa95c
        fi
        echo    'Loading Linux 3.13.0-33-generic ...'
        linux   /vmlinuz-3.13.0-33-generic root=UUID=xxxxxxxxxxxxxxxxx ro  quiet splash $vt_handoff
        echo    'Loading initial ramdisk ...'
        initrd  /initrd.img-3.13.0-33-generic
    }
    menuentry 'Ubuntu, with Linux 3.13.0-33-generic (recovery mode)' --class ubuntu --class gnu-linux --class gnu --class os $menuentry_id_option 'gnulinux-3.13.0-33-generic-recovery-c3444e01-a00a-4e4b-a73e-d213dc913a1e' {
        recordfail
        load_video
        insmod gzio
        insmod part_msdos
        insmod ext2
        set root='hd0,msdos6'
        if [ x$feature_platform_search_hint = xy ]; then
          search --no-floppy --fs-uuid --set=root --hint-bios=hd0,msdos6 --hint-efi=hd0,msdos6 --hint-baremetal=ahci0,msdos6  52381e81-2730-434f-93be-e8223c4aa95c
        else
          search --no-floppy --fs-uuid --set=root 52381e81-2730-434f-93be-e8223c4aa95c
        fi
        echo    'Loading Linux 3.13.0-33-generic ...'
        linux   /vmlinuz-3.13.0-33-generic root=UUID=xxxxxxxxxxxxxxxxxxx ro recovery nomodeset 
        echo    'Loading initial ramdisk ...'
        initrd  /initrd.img-3.13.0-33-generic
    }
    menuentry 'Ubuntu, with Linux 3.13.0-32-generic' --class ubuntu --class gnu-linux --class gnu --class os $menuentry_id_option 'gnulinux-3.13.0-32-generic-advanced-c3444e01-a00a-4e4b-a73e-d213dc913a1e' {
        recordfail
        load_video
        gfxmode $linux_gfx_mode
        insmod gzio
        insmod part_msdos
        insmod ext2
        set root='hd0,msdos6'
        if [ x$feature_platform_search_hint = xy ]; then
          search --no-floppy --fs-uuid --set=root --hint-bios=hd0,msdos6 --hint-efi=hd0,msdos6 --hint-baremetal=ahci0,msdos6  52381e81-2730-434f-93be-e8223c4aa95c
        else
          search --no-floppy --fs-uuid --set=root 52381e81-2730-434f-93be-e8223c4aa95c
        fi
        echo    'Loading Linux 3.13.0-32-generic ...'
        linux   /vmlinuz-3.13.0-32-generic root=UUID=xxxxxxxxxxxxxxxxxxxx ro  quiet splash $vt_handoff
        echo    'Loading initial ramdisk ...'
        initrd  /initrd.img-3.13.0-32-generic
    }
    menuentry 'Ubuntu, with Linux 3.13.0-32-generic (recovery mode)' --class ubuntu --class gnu-linux --class gnu --class os $menuentry_id_option 'gnulinux-3.13.0-32-generic-recovery-c3444e01-a00a-4e4b-a73e-d213dc913a1e' {
        recordfail
        load_video
        insmod gzio
        insmod part_msdos
        insmod ext2
        set root='hd0,msdos6'
        if [ x$feature_platform_search_hint = xy ]; then
          search --no-floppy --fs-uuid --set=root --hint-bios=hd0,msdos6 --hint-efi=hd0,msdos6 --hint-baremetal=ahci0,msdos6  52381e81-2730-434f-93be-e8223c4aa95c
        else
          search --no-floppy --fs-uuid --set=root 52381e81-2730-434f-93be-e8223c4aa95c
        fi
        echo    'Loading Linux 3.13.0-32-generic ...'
        linux   /vmlinuz-3.13.0-32-generic root=UUID=xxxxxxxxxxxxxxxxxxxxx ro recovery nomodeset 
        echo    'Loading initial ramdisk ...'
        initrd  /initrd.img-3.13.0-32-generic
    }
}

### END /etc/grub.d/10_linux ###

### BEGIN /etc/grub.d/20_linux_xen ###

### END /etc/grub.d/20_linux_xen ###

### BEGIN /etc/grub.d/20_memtest86+ ###
menuentry 'Memory test (memtest86+)' {
    insmod part_msdos
    insmod ext2
    set root='hd0,msdos6'
    if [ x$feature_platform_search_hint = xy ]; then
      search --no-floppy --fs-uuid --set=root --hint-bios=hd0,msdos6 --hint-efi=hd0,msdos6 --hint-baremetal=ahci0,msdos6  52381e81-2730-434f-93be-e8223c4aa95c
    else
      search --no-floppy --fs-uuid --set=root 52381e81-2730-434f-93be-e8223c4aa95c
    fi
    knetbsd /memtest86+.elf
}
menuentry 'Memory test (memtest86+, serial console 115200)' {
    insmod part_msdos
    insmod ext2
    set root='hd0,msdos6'
    if [ x$feature_platform_search_hint = xy ]; then
      search --no-floppy --fs-uuid --set=root --hint-bios=hd0,msdos6 --hint-efi=hd0,msdos6 --hint-baremetal=ahci0,msdos6  52381e81-2730-434f-93be-e8223c4aa95c
    else
      search --no-floppy --fs-uuid --set=root 52381e81-2730-434f-93be-e8223c4aa95c
    fi
    linux16 /memtest86+.bin console=ttyS0,115200n8
}
### END /etc/grub.d/20_memtest86+ ###

### BEGIN /etc/grub.d/30_os-prober ###
### END /etc/grub.d/30_os-prober ###

### BEGIN /etc/grub.d/30_uefi-firmware ###
### END /etc/grub.d/30_uefi-firmware ###

### BEGIN /etc/grub.d/40_custom ###
# This file provides an easy way to add custom menu entries.  Simply type the
# menu entries you want to add after this comment.  Be careful not to change
# the 'exec tail' line above.
### END /etc/grub.d/40_custom ###

### BEGIN /etc/grub.d/41_custom ###
if [ -f  ${config_directory}/custom.cfg ]; then
  source ${config_directory}/custom.cfg
elif [ -z "${config_directory}" -a -f  $prefix/custom.cfg ]; then
  source $prefix/custom.cfg;
fi
### END /etc/grub.d/41_custom ###

/etc/default/grub

# If you change this file, run 'update-grub' afterwards to update
# /boot/grub/grub.cfg.
# For full documentation of the options in this file, see:
#   info -f grub -n 'Simple configuration'

GRUB_DEFAULT=0
GRUB_HIDDEN_TIMEOUT=0
GRUB_HIDDEN_TIMEOUT_QUIET=true
GRUB_TIMEOUT=10
GRUB_DISTRIBUTOR=`lsb_release -i -s 2> /dev/null || echo Debian`
GRUB_CMDLINE_LINUX_DEFAULT="quiet splash"
GRUB_CMDLINE_LINUX=""

# Uncomment to enable BadRAM filtering, modify to suit your needs
# This works with Linux (no patch required) and with any kernel that obtains
# the memory map information from GRUB (GNU Mach, kernel of FreeBSD ...)
#GRUB_BADRAM="0x01234567,0xfefefefe,0x89abcdef,0xefefefef"

# Uncomment to disable graphical terminal (grub-pc only)
#GRUB_TERMINAL=console

# The resolution used on graphical terminal
# note that you can use only modes which your graphic card supports via VBE
# you can see them in real GRUB with the command `vbeinfo'
#GRUB_GFXMODE=640x480

# Uncomment if you don't want GRUB to pass "root=UUID=xxx" parameter to Linux
#GRUB_DISABLE_LINUX_UUID=true

# Uncomment to disable generation of recovery mode menu entries
#GRUB_DISABLE_RECOVERY="true"

# Uncomment to get a beep at grub start
#GRUB_INIT_TUNE="480 440 1"

Answer 1

Encrypted volumes are listed in /etc/crypttab. You need to update that file, to remove the volume that you no longer want mounted.

After doing this, you need to rebuild the initramfs, by running

sudo update-initramfs -u

If you want to have three encrypted partitions on the same disk, then you should have a single encrypted volume instead of three, and create partitions inside it (with LVM: make the encrypted volume a physical volume, create a volume group containing that physical volume, and create a logical volume for /, one for /home and one for swap). Ubuntu's startup scripts don't handle sharing the passphrase between volumes, though you can tweak them to do that; see bug #1022815.

By the way, you can use a random key (generated at each boot) for the swap volume, if you don't use hibernation.