| 摘要 |
A system comprises a processor running a hypervisor for virtual machines (VMs), a cache, e.g. a write-back cache, and a memory storing VM images for a differential check-pointing failover technique. The cache comprises rows having a memory address, a cache line, and an image modification flag. The modification flag is set (430) when a cache line is modified (420) by a backed-up VM (425), for which an image is saved in memory, while hypervisor actions in privilege mode do not set the flag. Flagged cache lines addresses are written in a log of the memory upon eviction (440) or during periodic checkpoints. Replication of the VM image in another memory can be obtained by fetching the cache lines stored at the logged addresses. Using the modification bit flag instead of dirty bit tags ensures that modified cache lines are written to the log without being flushed at the same time. |
