Unable to read files between two distros

Question

I have the following hard disk partition setup:

1. 256 GB SSD

/dev/sda1- FAT 32 -Mounted at /boot/efi

/dev/sda2 - Mounted at Filesystem Root

/dev/sda3 - Mounted at /usr

2. 1 TB HDD

/dev/sdb1 - Linux Swap

/dev/sdb2 - Mounted at /var

/dev/sdb3 - Mounted at /home

/dev/sdb4 - EFI System (unmounted)

/dev/sdb5 - Mounted at Filesystem Root of the 2nd distro (unmounted)

The two distros are Lubuntu and Elementary. In the above breakdown, Elementary is the unmounted one. Can someone tell me how to share files between these distros? Currently, I cannot open or execute any installed applications in Elementary that are from Lubuntu. I can't open several folders as well e.g. /usr/local/bin

Answer 1

Doing it manually

Mount the 2nd Distro with these commands

sudo mkdir /mnt/MyOtherDistro
sudo mount -t auto -v /dev/sdb5 /mnt/MyOtherDistro

Now you will be able to use Nautilus or any other file manager to navigate to the directory /mnt/MyOtherDistro to view / copy / delete files, etc.

You can also change to a directory in the 2nd Distro:

cd /mnt/MyOtherDistro/home/Me/Documents

When you are done unmount the partition and delete the directory:

sudo umount -l /mnt/MyOtherDistro
sudo rm -d /mnt/MyOtherDistro

Doing it with a bash script

As luck would have it I was just working on two scripts tonight to mount and unmount partitions via a command line scroll box.

Mount a partition

To mount a partition run the bash script sudo mount-menu.sh:

Highlight an unmounted partition and press Enter. It will be mounted and some basic information about the partition will be displayed:

=====================================================================
Mount Device:  /dev/nvme0n1p8
Mount Name:    /mnt/mount-menu.b9yZf
File System:   ext4
ID:            Ubuntu
RELEASE:       18.04
CODENAME:      bionic
DESCRIPTION:   Ubuntu 18.04 LTS
 Size  Used Avail Use%
  24G   17G  5.2G  77%

To create the script, copy the following to a file called /usr/local/bin/mount-menu.sh:

#!/bin/bash

# NAME: mount-menu.sh
# PATH: /usr/local/bin
# DESC: Select unmounted partition for mounting
# DATE: May 9, 2018. Modified May 11, 2018.

# $TERM variable may be missing when called via desktop shortcut
CurrentTERM=$(env | grep TERM)
if [[ $CurrentTERM == "" ]] ; then
    notify-send --urgency=critical \ 
                "$0 cannot be run from GUI without TERM environment variable."
    exit 1
fi

# Must run as root
if [[ $(id -u) -ne 0 ]] ; then echo "Usage: sudo $0" ; exit 1 ; fi

#
# Create unqique temporary file names
#

tmpMenu=$(mktemp /tmp/mount-menu.XXXXX)     # Menu list
tmpInfo=$(mktemp /tmp/mount-menu.XXXXX)     # Mount Parition Info
tmpWork=$(mktemp /tmp/mount-menu.XXXXX)     # Work file
MountName=$(mktemp -d /mnt/mount-menu.XXXXX)  # Mount directory name

#
# Function Cleanup () Removes temporary files
#

CleanUp () {
    [[ -f $tmpMenu ]] && rm -f $tmpMenu     # If temporary files created
    [[ -f $tmpInfo ]] && rm -f $tmpInfo     #  at various program stages
    [[ -f $tmpWork ]] && rm -f $tmpWork     #  remove them before exiting.
}


#
# Mainline
#

lsblk -o NAME,FSTYPE,LABEL,SIZE,MOUNTPOINT > $tmpMenu

i=0
SPACES='                                                                     '
DoHeading=true
AllPartsArr=()      # All partitions.

# Build whiptail menu tags ($i) and text ($Line) into array

while read -r Line; do
    if [[ $DoHeading == true ]] ; then
        DoHeading=false                     # First line is the heading.
        MenuText="$Line"                    # Heading for whiptail.
        FSTYPE_col="${Line%%FSTYPE*}"           
        FSTYPE_col="${#FSTYPE_col}"         # FS Type, ie `ext4`, `ntfs`, etc.
        MOUNTPOINT_col="${Line%%MOUNTPOINT*}"
        MOUNTPOINT_col="${#MOUNTPOINT_col}" # Required to ensure not mounted.
        continue
    fi

    Line="$Line$SPACES"                     # Pad extra white space.
    Line=${Line:0:74}                       # Truncate to 74 chars for menu.

    AllPartsArr+=($i "$Line")               # Menu array entry = Tag# + Text.
    (( i++ ))

done < $tmpMenu                             # Read next "lsblk" line.

#
# Display whiptail menu in while loop until no errors, or escape,
# or valid partion selection .
#

DefaultItem=0

while true ; do

    # Call whiptail in loop to paint menu and get user selection
    Choice=$(whiptail \
        --title "Use arrow, page, home & end keys. Tab toggle option" \
        --backtitle "Mount Partition" \
        --ok-button "Select unmounted partition" \
        --cancel-button "Exit" \
        --notags \
        --default-item "$DefaultItem" \
        --menu "$MenuText" 24 80 16 \
        "${AllPartsArr[@]}" \
        2>&1 >/dev/tty)

    clear                                   # Clear screen.
    if [[ $Choice == "" ]]; then            # Escape or dialog "Exit".
        CleanUp
        exit 1;
     fi

    DefaultItem=$Choice                     # whiptail start option.
    ArrNdx=$(( $Choice * 2 + 1))            # Calculate array offset.
    Line="${AllPartsArr[$ArrNdx]}"          # Array entry into $Line.

    # Validation - Don't wipe out Windows or Ubuntu 16.04:
    # - Partition must be ext4 and cannot be mounted.

    if [[ "${Line:MOUNTPOINT_col:4}" != "    " ]] ; then
        echo "Partition is already mounted."
        read -p "Press <Enter> to continue"
        continue
    fi

    # Build "/dev/Xxxxx" FS name from "├─Xxxxx" menu line
    MountDev="${Line%% *}"
    MountDev=/dev/"${MountDev:2:999}"

    # Build File System Type
    MountType="${Line:FSTYPE_col:999}"
    MountType="${MountType%% *}"

    break                                   # Validated: Break menu loop.

done                                        # Loop while errors.

#
# Mount partition
#

echo ""
echo "====================================================================="
mount -t auto $MountDev $MountName


# Display partition information.
echo "Mount Device=$MountDev" > $tmpInfo
echo "Mount Name=$MountName" >> $tmpInfo
echo "File System=$MountType" >> $tmpInfo

# Build Mount information (the partition selected for cloning to)
LineCnt=$(ls $MountName | wc -l)
if (( LineCnt > 2 )) ; then 
    # More than /Lost+Found exist so it's not an empty partition.
    if [[ -f $MountName/etc/lsb-release ]] ; then
        cat $MountName/etc/lsb-release >> $tmpInfo
    else
        echo "No LSB-Release file on Partition." >> $tmpInfo
    fi
else
    echo "Partition appears empty" >> $tmpInfo
    echo "/Lost+Found normal in empty partition" >> $tmpInfo
    echo "First two files/directories below:" >> $tmpInfo
    ls $MountName | head -n2 >> $tmpInfo
fi

sed -i 's/DISTRIB_//g' $tmpInfo      # Remove DISTRIB_ prefix.
sed -i 's/=/:=/g' $tmpInfo           # Change "=" to ":="
sed -i 's/"//g' $tmpInfo             # Remove " around "Ubuntu 16.04...".

# Align columns from "Xxxx:=Yyyy" to "Xxxx:      Yyyy"
cat $tmpInfo | column -t -s '=' > $tmpWork
cat $tmpWork > $tmpInfo

# Mount device free bytes
df -h --output=size,used,avail,pcent "$MountDev" >> $tmpInfo

# Display partition information.
cat $tmpInfo

CleanUp                             # Remove temporary files

exit 0

Unmount a partition

To unmount the partition setup by mount-menu.sh run the command sudo umount-menu.sh. The same screen shown above appears except the partition is already mounted and you select it to unmount it. First you need to create the script /usr/local/bin/umount-menu.sh and copy in the lines below:

#!/bin/bash

# NAME: umount-menu.sh
# PATH: /usr/local/bin
# DESC: Select mounted partition for unmounting
# DATE: May 10, 2018. Modified May 11, 2018.

# $TERM variable may be missing when called via desktop shortcut
CurrentTERM=$(env | grep TERM)
if [[ $CurrentTERM == "" ]] ; then
    notify-send --urgency=critical \ 
                "$0 cannot be run from GUI without TERM environment variable."
    exit 1
fi

# Must run as root
if [[ $(id -u) -ne 0 ]] ; then echo "Usage: sudo $0" ; exit 1 ; fi

#
# Create unqique temporary file names
#

tmpMenu=$(mktemp /tmp/mount-menu.XXXXX)   # Menu list

#
# Function Cleanup () Removes temporary files
#

CleanUp () {
    [[ -f "$tmpMenu" ]] && rm -f "$tmpMenu" #  at various program stages
}


#
# Mainline
#

lsblk -o NAME,FSTYPE,LABEL,SIZE,MOUNTPOINT > "$tmpMenu"

i=0
SPACES='                                                                     '
DoHeading=true
AllPartsArr=()      # All partitions.

# Build whiptail menu tags ($i) and text ($Line) into array

while read -r Line; do
    if [[ $DoHeading == true ]] ; then
        DoHeading=false                     # First line is the heading.
        MenuText="$Line"                    # Heading for whiptail.
        MOUNTPOINT_col="${Line%%MOUNTPOINT*}"
        MOUNTPOINT_col="${#MOUNTPOINT_col}" # Required to ensure mounted.
        continue
    fi

    Line="$Line$SPACES"                     # Pad extra white space.
    Line=${Line:0:74}                       # Truncate to 74 chars for menu.

    AllPartsArr+=($i "$Line")               # Menu array entry = Tag# + Text.
    (( i++ ))

done < "$tmpMenu"                           # Read next "lsblk" line.

#
# Display whiptail menu in while loop until no errors, or escape,
# or valid partion selection .
#

DefaultItem=0

while true ; do

    # Call whiptail in loop to paint menu and get user selection
    Choice=$(whiptail \
        --title "Use arrow, page, home & end keys. Tab toggle option" \
        --backtitle "Mount Partition" \
        --ok-button "Select unmounted partition" \
        --cancel-button "Exit" \
        --notags \
        --default-item "$DefaultItem" \
        --menu "$MenuText" 24 80 16 \
        "${AllPartsArr[@]}" \
        2>&1 >/dev/tty)

    clear                                   # Clear screen.

    if [[ $Choice == "" ]]; then            # Escape or dialog "Exit".
        CleanUp
        exit 1;
     fi

    DefaultItem=$Choice                     # whiptail start option.
    ArrNdx=$(( $Choice * 2 + 1))            # Calculate array offset.
    Line="${AllPartsArr[$ArrNdx]}"          # Array entry into $Line.

    if [[ "${Line:MOUNTPOINT_col:15}" != "/mnt/mount-menu" ]] ; then
        echo "Only Partitions mounted by mount-menu.sh can be unounted."
        read -p "Press <Enter> to continue"
        continue
    fi

    # Build "/dev/Xxxxx" FS name from "├─Xxxxx" menu line
    MountDev="${Line%% *}"
    MountDev=/dev/"${MountDev:2:999}"

    # Build Mount Name
    MountName="${Line:MOUNTPOINT_col:999}"
    MountName="${MountName%% *}"

    break                                   # Validated: Break menu loop.

done                                        # Loop while errors.

#
# Unmount partition
#

echo ""
echo "====================================================================="
umount "$MountName" -l                      # Unmount the clone
rm  -d "$MountName"                         # Remove clone directory

echo $(tput bold)                           # Set to bold text
echo $MountDev mounted on $MountName unmounted.
echo $(tput sgr0)                           # Reset to normal text

CleanUp                                     # Remove temporary files

exit 0

Make them executable

After creating the files, both scripts must be marked executable:

sudo chmod a+x /usr/local/bin/mount-menu.sh
sudo chmod a+x /usr/local/bin/umount-menu.sh