Abstract: A memory hierarchy includes a first memory and a second memory that is at a lower position in the memory hierarchy than the first memory. A method of managing the memory hierarchy includes: observing, over a first period of time, accesses to pages of the first memory; in response to determining that no page in a first group of pages was accessed during the first period of time, moving each page in the first group of pages from the first memory to the second memory; and in response to determining that the number of pages in other groups of pages of the first memory, which were accessed during the first period of time, is less than a threshold number of pages, moving each page in the other group of pages, that was not accessed during the first period of time from the first memory to the second memory.

Abstract: A virtual machine (VM) is migrated from a source host to a destination host in a virtualized computing system, the VM having a plurality of virtual central processing units (CPUs). The method includes copying, by VM migration software executing in the source host and the destination host, memory of the VM from the source host to the destination host by installing, at the source host, write traces spanning all of the memory and then copying the memory from the source host to the destination host over a plurality of iterations; and performing switch-over, by the VM migration software, to quiesce the VM in the source host and resume the VM in the destination host. The VM migration software installs write traces using less than all of the virtual CPUs, and using trace granularity larger than a smallest page granularity.

Abstract: A virtual machine (VM) is migrated from a source host to a destination host in a virtualized computing system, the VM having a plurality of virtual central processing units (CPUs). The method includes copying, by VM migration software executing in the source host and the destination host, memory of the VM from the source host to the destination host by installing, at the source host, write traces spanning all of the memory and then copying the memory from the source host to the destination host over a plurality of iterations; and performing switch-over, by the VM migration software, to quiesce the VM in the source host and resume the VM in the destination host. The VM migration software installs write traces using less than all of the virtual CPUs, and using trace granularity larger than a smallest page granularity.