US Patent 9996440 Fault tolerance using shared memory architecture

Examples provide a fault tolerant virtual machine (VM) using pooled memory. When fault tolerance is enabled for a VM, a primary VM is created on a first host in a server cluster. A secondary VM is created on a second host in the server cluster. Memory for the VMs is maintained on a shared partition in pooled memory. The pooled memory is accessible to all hosts in the cluster. The primary VM has read and write access to the VM memory in the pooled memory. The secondary VM has read-only access to the VM memory. If the second host fails, a new secondary VM is created on another host in the cluster. If the first host fails, the secondary VM becomes the new primary VM and a new secondary VM is created on another host in the cluster.