Environment

  • Red Hat Enterprise Linux 6 all versions
  • 64 bit and 32 bit guest
  • VMware ESX 5.5 , 5.1 , 5.0 , 4.1 , 4,0(It includes the update release version)

Issue

  • Hot-add vCPU and memory to VMWare RHEL 6 guests

  • The structure of the /sys/devices/system/cpu/ tree has changed, and it looks like I cannot edit the online or offline files. Added a CPU via VMWare, and trying to figure out how to enable it so the OS will use it.

Resolution

For rhel6 32 bit guest vmware does not support Hot Add Memory or Hot Add vCPU. For 64 bit rhel 6/6.1 guest hot add is supported.

Check the vmware comparability guide for details on various rhel OS versions. Click on the below link.

VMware Compatibility Guide

From the link select the Product Name [ESX/ESXI] and the OS Family Name to see what is supported. For example below link gives

Rhel 6.2 32 bit guest support