White Papers

6
Dell EMC Fault Resilient Memory
Introduction to Dell Fault Resilient Memory (FRM)
1.4 Behavioral description of FRM on yx4x PowerEdge servers and later
On the yx4x PowerEdge server, only FRM operating mode is supported. Overall 25 percentage of system
memory is reserved for reliable memory region. The 25 percentage of the total system memory populated on
the server is reserved for reliable region. The 75 percentage of the total system memory populated is
available for the end user applications for general purpose use.
• When FRM is enabled with the Node Interleaving option set to enable, then the 25 percentage
reliable memory region is occupied across the sockets.
• When FRM is enabled with the Node Interleaving option set to disable (NUMA Enabled), then the 25
percentage reliable memory region is occupied from 1
st
socket and then followed by the 2
nd
socket
until the 25 percentage is reserved. However, if there is a case arises where complete NUMA Node
memory needs to be used to complete 25 percentage reservation, then BIOS further divides the
allocation between NUMA nodes to ensure there is no major NUMA imbalance.
1.5 Enabling FRM in PowerEdge servers
To enable FRM on the supported Dell EMC PowerEdge server, complete the following steps:
1. In the BIOS setup, select Memory Settings.
2. Under the Memory Operating Mode section, select Dell Fault Resilient Mode.
3. Click Save and exit from the BIOS setup.
Installing VMware ESXi 5.5 GA or later on the server (ensure to look at VMware HCL to select the supported
ESXi version against the specific server model) makes vmkernel and other critical applications or services
loads into the reliable region by default. If you are using an edition of VMware vSphere with the Reliable
Memory feature enabled, it will automatically locate the FRM space and load the hypervisor into the
protected zone. The user does not have to do any configuration changes within ESXi or vCenter to enable
ReM.
Note: It is recommended that you must NOT enable FRM on earlier vSphere versions than 5.5, or any other
OS. If you do so, while the system will function, but the memory used to create the fault tolerant zone will be
still consumed and the protected zone will be used randomly, thus causing the wastage of system memory.