1 / 14

COMP25212: Virtualization 3

COMP25212: Virtualization 3. Subtitle: “What can we do to a VM?” Learning Objectives: To understand the VM-handling mechanisms of a hypervisor To understand how many different value-added services are constructed on top of VM-handling mechanisms. Stopping a VM.

leala
Download Presentation

COMP25212: Virtualization 3

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. COMP25212: Virtualization 3 Subtitle: “What can we do to a VM?” Learning Objectives: • To understand the VM-handling mechanisms of a hypervisor • To understand how many different value-added services are constructed on top of VM-handling mechanisms COMP25212

  2. Stopping a VM Hypervisor stops and starts VM all the time: • to share CPUs • to serialize access to resources • Stop by: • Saving CPU registers into Hypervisor data area Applications Applications Guest AOperating System Guest BOperating System Virtual Machine Monitor/Hypervisor Host Hardware Virtualized COMP25212

  3. Starting a VM • Hypervisor: • gains control (e.g. clock tick) • saves previous VM’s CPU registers • loads next VM’s CPU registers • jumps to next VM’s next-PC (in correct privilege state) Applications Applications Guest AOperating System Guest BOperating System Virtual Machine Monitor/Hypervisor Host Hardware Virtualized COMP25212

  4. VM State While Stopped VM State: • Memory (all guest physical memory) • includes Application state, OS state • CPU state (registers) • Small amount of I/O state • Let’s stop VM whenI/O is quiescent! Applications Applications Guest AOperating System Guest BOperating System Virtual Machine Monitor/Hypervisor Host Hardware Virtualized COMP25212

  5. “Freeze” a VM • Once suspended, the VM image is self-contained • VM can be (e.g.) copied to a file (LARGE file!) • Now, what else can we do with this? Applications Guest AOperating System CPU registers I/O state COMP25212

  6. Move a VM Applications Applications Applications Applications Guest AOperating System Guest BOperating System Guest BOperating System Guest COperating System Virtual Machine Monitor/Hypervisor Virtual Machine Monitor/Hypervisor Host Hardware X Host Hardware Y Virtualized Virtualized COMP25212

  7. Snapshot and Rollback a VM Applications Applications Applications Applications Guest BOperating System Guest BOperating System Guest AOperating System Guest BOperating System Snapshot 1 Virtual Machine Monitor/Hypervisor … Host Hardware Virtualized Snapshot n Think: Optimizations? COMP25212

  8. Archive a VM Applications Applications Guest BOperating System Guest BOperating System COMP25212

  9. Rapid Provisioning Applications Guest BOperating System Applications Guest COperating System Virtual Machine Monitor/Hypervisor Host Hardware Virtualized COMP25212

  10. Virtual Appliances • http://www.vmware.com/appliances/directory/ • over 1000 downloadable appliances Applications Applications Applications Applications Applications Applications Applications Applications Guest BOperating System Guest BOperating System Guest BOperating System Guest BOperating System Guest BOperating System Guest BOperating System Guest BOperating System Guest BOperating System • e.g.: • mail server • web server • hotel system • virus scanner • firewall COMP25212

  11. Deploying Secure Desktops Applications Guest Operating System Virtual Machine Monitor/Hypervisor Host Hardware Virtualized Desktop Machine COMP25212

  12. Live Migration • Optimizing live migration from “source” to “destination” VMM: • Copy every page from “source” to “destination” machine • reset “dirty” bit in VMM’s page table for every page copied • Repeat: • Find next non-“dirty” page in “source” machine • Copy to “destination” machine and reset “dirty” bit • Until only minimal subset of pages left • Suspend VM on “source” • Copy remaining pages to “destination” • Resume VM on “destination” COMP25212

  13. Load Balancing • Management software monitors “load” on all physical machines • If loads are mismatched, migrate a VM from a loaded to a less-loaded machine Independent of Application! Independent of Operating System! COMP25212

  14. High Availability • For critical applications, keep a standby VM available on a different hardware system • Regularly copy active VM image to standby VM (but don’t activate it) • Activate standby VM if active VM stops responding (VM crashes? VMM crashes? Hardware system fails?) Independent of Application! Independent of Operating System! COMP25212

More Related