disk_part.sh

#!/bin/bash

#################################################################################
# Script to partition automatically new disks added to a linux machine.         #
# The script will create a single partition on the whole free space of the disk #
#################################################################################


# Setting the logfile location
logfile=/var/log/disk_part.log

# Logging all actions 
exec 3>&1 4>&2
trap 'exec 2>&4 1>&3' 0 1 2 3
exec 1>$logfile 2>&1

# Logging the start date and time
date +"%F_%R"

if [ "${UID}" -ne 0 ];
then
    echo "Script executed without root permissions"
    echo "You must be root to run this program." >&2
    exit 3
fi

is_partitioned() {
    OUTPUT=$(partx -s ${1} 2>&1)
    egrep "partition table does not contains usable partitions|failed to read partition table" <<< "${OUTPUT}" >/dev/null 2>&1
    if [ ${?} -eq 0 ]; then
        return 1
    else
        return 0
    fi
}

has_filesystem() {
    DEVICE=${1}
    OUTPUT=$(file -L -s ${DEVICE})
    grep filesystem <<< "${OUTPUT}" > /dev/null 2>&1
    return ${?}
}

scan_for_new_disks() {
    # Looks for unpartitioned disks
    declare -a RET
    DEVS=($(ls -1 /dev/sd*|egrep -v "[0-9]$"))
    for DEV in "${DEVS[@]}";
    do
        # The disk will be considered a candidate for partitioning
        # and formatting if it does not have a sd?1 entry or
        # if it does have an sd?1 entry and does not contain a filesystem
        is_partitioned "${DEV}"
        if [ ${?} -eq 0 ];
        then
            has_filesystem "${DEV}1"
            if [ ${?} -ne 0 ];
            then
                RET+=" ${DEV}"
            fi
        else
            RET+=" ${DEV}"
        fi
    done
    echo "${RET}"
}

do_partition() {
# This function creates one (1) primary partition on the
# disk, using all available space
    _disk=${1}
    _type=${2}
    if [ -z "${_type}" ]; then
        # default to Linux partition type (ie, ext3/ext4/xfs)
        _type=83
    fi
    echo "n
p
1


t
${_type}
w"| fdisk "${_disk}"

#
# Use the bash-specific $PIPESTATUS to ensure we get the correct exit code
# from fdisk and not from echo
if [ ${PIPESTATUS[1]} -ne 0 ];
then
    echo "An error occurred partitioning ${_disk}" >&2
    echo "I cannot continue" >&2
    exit 2
fi
}
#end do_partition

scan_partition_format()
{
    log "Begin scanning and formatting data disks"

    DISKS=($(scan_for_new_disks))

	if [ "${#DISKS}" -eq 0 ];
	then
	    log "No unpartitioned disks without filesystems detected"
	    return
	fi
	echo "Disks are ${DISKS[@]}"
	for DISK in "${DISKS[@]}";
	do
	    echo "Working on ${DISK}"
	    is_partitioned ${DISK}
	    if [ ${?} -ne 0 ];
	    then
	        echo "${DISK} is not partitioned, partitioning"
	        do_partition ${DISK}
	    fi
	    PARTITION=$(fdisk -l ${DISK}|grep -A 1 Device|tail -n 1|awk '{print $1}')
	    has_filesystem ${PARTITION}
	    if [ ${?} -ne 0 ];
	    then
	        echo "Creating filesystem on ${PARTITION}."
	#        echo "Press Ctrl-C if you don't want to destroy all data on ${PARTITION}"
	#        sleep 10
	        mkfs -j -t ext4 ${PARTITION}
	    fi
	done
}

# Create Partitions
DISKS=$(scan_for_new_disks)
scan_partition_format