Virtualization has made our lives easier. We can spin up new resources for applications, dynamically add more disk space, migrate them, etc. In vSphere, we can dynamically add additional memory and…

#!/bin/bash
# Based on script by William Lam - http://engineering.ucsb.edu/~duonglt/vmware/

# Bring CPUs online
for CPU in $(ls /sys/devices/system/cpu/ |grep -E '(cpu[0-9])')
do
    CPU_DIR="/sys/devices/system/cpu/${CPU}"
    echo "Found cpu: \"${CPU_DIR}\" ..."
    CPU_STATE_FILE="${CPU_DIR}/online"
    if [ -f "${CPU_STATE_FILE}" ]; then
            STATE=$(cat "${CPU_STATE_FILE}" | grep 1)
            if [ "${STATE}" == "1" ]; then
                    echo -e "\t${CPU} already online"
            else
                     echo -e "\t${CPU} is new cpu, onlining cpu ..."
                     echo 1 > "${CPU_STATE_FILE}"
            fi
    else 
            echo -e "\t${CPU} already configured prior to hot-add"
    fi
done

# Bring all new Memory online
for RAM in $(grep line /sys/devices/system/memory/*/state)
do
    echo "Found ram: ${RAM} ..."
    if [[ "${RAM}" == *":offline" ]]; then
            echo "Bringing online"
            echo $RAM | sed "s/:offline$//"|sed "s/^/echo online > /"|source /dev/stdin
    else
            echo "Already online"
    fi
done