MAC OS X, Linux, Windows and other IT Tips and Tricks

22 May 15 Extending dynamically Linux RAMs in VMWare VM without rebooting

Need to raise the amount of RAM in a VMWare VM without rebooting.

– In VMWare interface: Raise the amount of RAM for the VM
– In the Linux VM: Run the following script:

# This script enables in system the unrecognized RAMs
deleteline () {
echo -ne $dellineup
### check preconditions ###
if ! type -P $modprobe > /dev/null; then
echo -e "'modprobe' package is not installed! \n z.B. apt-get install modprobe"
### check if there is any offline RAM ###
RAMOFFLINE=`grep offline /sys/devices/system/memory/*/state|wc -l`
if [ $RAMOFFLINE -gt 0 ]; then
echo "RAMs found that are not yet recognized by the system. Enable RAMs live recognition? (y/N)" ; read yesno ; deleteline
case "$yesno" in
echo -e "Recognition of unused RAMs will now be enabled"
modprobe acpiphp
modprobe acpi_memhotplug
for i in $(grep -l offline /sys/devices/system/memory/*/state);do echo online > $i;done
echo -e "\n\n"
free -m
echo -e "Process cancelled"
echo "No Unrecognized RAMs present."

Check the new amount of RAM:
free | grep Mem

XEN NOTE: With XEN environment it appears that the System/Kernel immediately recognizes the new amount of RAM dynamically without the need to run this above script.

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