Patent application number | Description | Published |
20080244535 | Logging and Replaying Input/Output Events for a Virtual Machine - Methods for logging and replaying input/output (I/O) events for a virtual machine (VM). The I/O events may be asynchronous or synchronous. In particular, one embodiment is a computer-implemented method for logging input/output (I/O) events for a virtual machine, the method including: executing the virtual machine from a checkpoint; and logging external events, including I/O events; wherein logging an I/O event comprises logging the event, and then, logging I/O data relating to the I/O event. | 10-02-2008 |
20080294808 | DIRECT ACCESS TO A HARDWARE DEVICE FOR VIRTUAL MACHINES OF A VIRTUALIZED COMPUTER SYSTEM - In a virtualized computer system in which a guest operating system runs on a virtual machine of a virtualized computer system, a computer-implemented method of providing the guest operating system with direct access to a hardware device coupled to the virtualized computer system via a communication interface, the method including: (a) obtaining first configuration register information corresponding to the hardware device, the hardware device connected to the virtualized computer system via the communication interface; (b) creating a passthrough device by copying at least part of the first configuration register information to generate second configuration register information corresponding to the passthrough device; and (c) enabling the guest operating system to directly access the hardware device corresponding to the passthrough device by providing access to the second configuration register information of the passthrough device. | 11-27-2008 |
20080294825 | Handling Interrupts When Virtual Machines Have Direct Access to a Hardware Device - In virtualized computer system in which a guest operating system runs on a virtual machine of a virtualized computer system and has direct access to a hardware device coupled to the virtualized computer system via a communication interface, a computer-implemented method of handling interrupts from the hardware device to the guest operating system includes: (a) receiving a physical interrupt from the hardware device on a shared interrupt line of an interrupt controller; (b) masking the shared interrupt line of the interrupt controller; (c) generating a virtual interrupt corresponding to the physical interrupt to the guest operating system; and (d) the guest operating system executing an interrupt service routine. | 11-27-2008 |
20090007111 | LOGGING AND REPLAYING INPUT/OUTPUT EVENTS FOR A VIRTUAL MACHINE - Methods for logging and replaying input/output (I/O) events for a virtual machine (VM). The I/O events may be asynchronous or synchronous. In particular, one embodiment is a computer-implemented method for logging input/output (I/O) events for a virtual machine, the method including: executing the virtual machine from a checkpoint; and logging external events, including I/O events; wherein logging an I/O event comprises logging the event, and then, logging I/O data relating to the I/O event. | 01-01-2009 |
20090113109 | Using Virtual Machine Cloning To Create a Backup Virtual Machine in a Fault Tolerant System - Techniques for creating a fault tolerant system in a virtual machine environment utilize a primary VM and a backup VM. To initialize the fault tolerant system, the backup VM and primary VM start from the same state. To achieve this in one embodiment, the primary VM is suspended and the state of the primary VM is copied to the backup VM. Once the backup VM has received all the primary VM's state, the primary VM is resumed. Subsequent state changes of the primary VM are buffered until the backup VM resumes, connects to the primary VM, and starts consuming the buffered content. Thereafter, synchronization is maintained by the primary VM's writing relevant state changes to a log and the backup VM's reading such relevant state changes from the log. | 04-30-2009 |
20090119493 | Using Branch Instruction Counts to Facilitate Replay of Virtual Machine Instruction Execution - A method and computer program product for logging non-deterministic events of a virtual machine executing a sequence guest instructions, the method including tracking an execution point in the sequence of executing guest instructions, the tracking of the execution point including determining a branch count of executed branch instructions; and detecting an occurrence of a non-deterministic event directed to the virtual machine during execution of the sequence of guest instructions, and recording information which includes an identifier of a current execution point, wherein the identifier includes the branch count. | 05-07-2009 |
20090119538 | Storage Handling for Fault Tolerance in Virtual Machines - A fault-tolerant virtualized computer system comprises a primary host executing a primary virtual machine (VM) and a backup host executing a backup VM. In one embodiment, each VM includes a virtual disk mapped to a shared disk image on physical disk accessible to both hosts. A virtual disk IO request is received by virtualization software executing on the backup host from a backup VM. When the virtual disk IO request is a read request, the virtual disk IO request is mapped to a physical read IO request of a virtual disk image stored on a physical disk, the physical read IO request is issued to the physical disk. However, when the virtual disk IO request is a write request, it is assumed to be completed without mapping the virtual disk IO request or issuing a mapped physical IO request to the physical disk. | 05-07-2009 |
20090119665 | TRANSITIONING OF VIRTUAL MACHINE FROM REPLAY MODE TO LIVE MODE - A backup VM is allowed to enter live execution mode at instruction boundaries but not in the middle of emulation of a single instruction. This is accomplished by having the last log entry of multiple entries generated during emulation of an instruction to have an indication of a “go-live” point and by having the backup VM not replay log entries provided by the primary VM beyond the log entry that indicates the “go-live” point. | 05-07-2009 |
20090125904 | VIRTUAL MACHINE MIGRATION - A source virtual machine (VM) hosted on a source server is migrated to a destination VM on a destination server without first powering down the source VM. After optional pre-copying of the source VM's memory to the destination VM, the source VM is suspended and its non-memory state is transferred to the destination VM; the destination VM is then resumed from the transferred state. The source VM memory is either paged in to the destination VM on demand, or is transferred asynchronously by pre-copying and write-protecting the source VM memory, and then later transferring only the modified pages after the destination VM is resumed. The source and destination servers preferably share common storage, in which the source VM's virtual disk is stored; this avoids the need to transfer the virtual disk contents. Network connectivity is preferably also made transparent to the user by arranging the servers on a common subnet, with virtual network connection addresses generated from a common name space of physical addresses. | 05-14-2009 |
20100122052 | Generating and Using Checkpoints in a Virtual Computer System - To generate a checkpoint for a virtual machine (VM), first, while the VM is still running, a copy-on-write (COW) disk file is created pointing to a parent disk file that the VM is using. Next, the VM is stopped, the VM' s memory is marked COW, the device state of the VM is saved to memory, the VM is switched to use the COW disk file, and the VM begins running again for substantially the remainder of the checkpoint generation. Next, the device state that was stored in memory and the unmodified VM memory pages are saved to a checkpoint file. Also, a copy may be made of the parent disk file for retention as part of the checkpoint, or the original parent disk file may be retained as part of the checkpoint. If a copy of the parent disk file was made, then the COW disk file may be committed to the original parent disk file. | 05-13-2010 |
20100169537 | Virtual Machine Migration - A source virtual machine (VM) hosted on a source server is migrated to a destination VM on a destination server without first powering down the source VM. After optional pre-copying of the source VM's memory to the destination VM, the source VM is suspended and its non-memory state is transferred to the destination VM; the destination VM is then resumed from the transferred state. The source VM memory is either paged in to the destination VM on demand, or is transferred asynchronously by pre-copying and write-protecting the source VM memory, and then later transferring only the modified pages after the destination VM is resumed. The source and destination servers preferably share common storage, in which the source VM's virtual disk is stored; this avoids the need to transfer the virtual disk contents. Network connectivity is preferably also made transparent to the user by arranging the servers on a common subnet, with virtual network connection addresses generated from a common name space of physical addresses. | 07-01-2010 |
20110113428 | SCSI Protocol Emulation for Virtual Storage Device Stored on NAS Device - A virtualization technique, in accordance with one embodiment of the present invention, includes emulating the small computing system interface (SCSI) protocol to access a virtual SCSI storage device backed by a file stored on network attached storage (NAS). | 05-12-2011 |
20110167194 | Method and System for Frequent Checkpointing - A virtualization platform provides fault tolerance for a primary virtual machine by continuously transmitting checkpoint information of the primary virtual machine to a collector process, such as a backup virtual machine. When implemented on a hardware platform comprising a multi-processor that supports nested page tables, the virtualization platform leverages the nested page table support to quickly identify memory pages that have been modified between checkpoints. The backup virtual machine provides feedback information to assist the virtualization platform in identifying candidate memory pages for transmitting actual modifications to the memory pages rather than the entire memory page as part of the checkpoint information. The virtualization platform further maintains a modification history data structure to identify memory pages that can be transmitted simultaneous with the execution of the primary virtual machine rather than while the primary virtual machine has been stunned. | 07-07-2011 |
20110167195 | Method and System for Frequent Checkpointing - A virtualization platform provides fault tolerance for a primary virtual machine by continuously transmitting checkpoint information of the primary virtual machine to a collector process, such as a backup virtual machine. When implemented on a hardware platform comprising a multi-processor that supports nested page tables, the virtualization platform leverages the nested page table support to quickly identify memory pages that have been modified between checkpoints. The backup virtual machine provides feedback information to assist the virtualization platform in identifying candidate memory pages for transmitting actual modifications to the memory pages rather than the entire memory page as part of the checkpoint information. The virtualization platform further maintains a modification history data structure to identify memory pages that can be transmitted simultaneous with the execution of the primary virtual machine rather than while the primary virtual machine has been stunned. | 07-07-2011 |
20110167196 | Method and System for Frequent Checkpointing - A virtualization platform provides fault tolerance for a primary virtual machine by continuously transmitting checkpoint information of the primary virtual machine to a collector process, such as a backup virtual machine. When implemented on a hardware platform comprising a multi-processor that supports nested page tables, the virtualization platform leverages the nested page table support to quickly identify memory pages that have been modified between checkpoints. The backup virtual machine provides feedback information to assist the virtualization platform in identifying candidate memory pages for transmitting actual modifications to the memory pages rather than the entire memory page as part of the checkpoint information. The virtualization platform further maintains a modification history data structure to identify memory pages that can be transmitted simultaneous with the execution of the primary virtual machine rather than while the primary virtual machine has been stunned. | 07-07-2011 |
20110258625 | GENERATING AND USING CHECKPOINTS IN A VIRTUAL COMPUTER SYSTEM - To generate a checkpoint for a virtual machine (VM), first, while the VM is still running, a copy-on-write (COW) disk file is created pointing to a parent disk file that the VM is using. Next, the VM is stopped, the VM's memory is marked COW, the device state of the VM is saved to memory, the VM is switched to use the COW disk file, and the VM begins running again for substantially the remainder of the checkpoint generation. Next, the device state that was stored in memory and the unmodified VM memory pages are saved to a checkpoint file. Also, a copy may be made of the parent disk file for retention as part of the checkpoint, or the original parent disk file may be retained as part of the checkpoint. If a copy of the parent disk file was made, then the COW disk file may be committed to the original parent disk file. | 10-20-2011 |
20120185453 | SCSI PROTOCOL EMULATION FOR VIRTUAL STORAGE DEVICE STORED ON NAS DEVICE - A virtualization technique, in accordance with one embodiment of the present invention, includes emulating the small computing system interface (SCSI) protocol to access a virtual SCSI storage device backed by a file stored on network attached storage (NAS). | 07-19-2012 |
20120185553 | SELECTING A MASTER NODE USING A SUITABILITY VALUE - Selecting a master node in a group of computing nodes. Computing nodes exchange suitability messages, candidate messages, and master messages to indicate the state of each node. A deterministic algorithm based on scores and timings is executed by each computing node to encourage each node to select the same master node. | 07-19-2012 |
20120278801 | MAINTAINING HIGH AVAILABILITY OF A GROUP OF VIRTUAL MACHINES USING HEARTBEAT MESSAGES - Embodiments maintain high availability of software application instances in a fault domain. Subordinate hosts are monitored by a master host. The subordinate hosts publish heartbeats via a network and datastores. Based at least in part on the published heartbeats, the master host determines the status of each subordinate host, distinguishing between subordinate hosts that are entirely inoperative and subordinate hosts that are operative but partitioned (e.g., unreachable via the network). The master host may restart software application instances, such as virtual machines, that are executed by inoperative subordinate hosts or that cease executing on partitioned subordinate hosts. | 11-01-2012 |
20130060947 | VIRTUAL MACHINE MIGRATION - A source virtual machine (VM) hosted on a source server is migrated to a destination VM on a destination server without first powering down the source VM. After optional pre-copying of the source VM's memory to the destination VM, the source VM is suspended and its non-memory state is transferred to the destination VM; the destination VM is then resumed from the transferred state. The source VM memory is either paged into the destination VM on demand, or is transferred asynchronously by pre-copying and write-protecting the source VM memory, and then later transferring only the modified pages after the destination VM is resumed. The source and destination servers preferably share common storage, in which the source VM's virtual disk is stored; this avoids the need to transfer the virtual disk contents. | 03-07-2013 |
20130097398 | GENERATING AND USING CHECKPOINTS IN A VIRTUAL COMPUTER SYSTEM - To generate a checkpoint for a virtual machine (VM), first, while the VM is still running, a copy-on-write (COW) disk file is created pointing to a parent disk file that the VM is using. Next, the VM is stopped, the VM's memory is marked COW, the device state of the VM is saved to memory, the VM is switched to use the COW disk file, and the VM begins running again for substantially the remainder of the checkpoint generation. Next, the device state that was stored in memory and the unmodified VM memory pages are saved to a checkpoint file. Also, a copy may be made of the parent disk file for retention as part of the checkpoint, or the original parent disk file may be retained as part of the checkpoint. If a copy of the parent disk file was made, then the COW disk file may be committed to the original parent disk file. | 04-18-2013 |
20130246355 | USING VIRTUAL MACHINE CLONING TO CREATE A BACKUP VIRTUAL MACHINE IN A FAULT TOLERANT SYSTEM - Techniques for creating a fault tolerant system in a virtual machine environment utilize a primary VM and a backup VM. To initialize the fault tolerant system, the backup VM and primary VM start from the same state. To achieve this in one embodiment, the primary VM is suspended and the state of the primary VM is copied to the backup VM. Once the backup VM has received all the primary VM's state, the primary VM is resumed. Subsequent state changes of the primary VM are buffered until the backup VM resumes, connects to the primary VM, and starts consuming the buffered content. Thereafter, synchronization is maintained by the primary VM's writing relevant state changes to a log and the backup VM's reading such relevant state changes from the log. | 09-19-2013 |
20130254505 | SCSI PROTOCOL EMULATION FOR VIRTUAL STORAGE DEVICE STORED ON NAS DEVICE - A virtualization technique, in accordance with one embodiment of the present invention, includes emulating the small computing system interface (SCSI) protocol to access a virtual SCSI storage device backed by a file stored on network attached storage (NAS). | 09-26-2013 |
20140013010 | DIRECT ACCESS TO A HARDWARE DEVICE FOR VIRTUAL MACHINES OF A VIRTUALIZED COMPUTER SYSTEM - In a virtualized computer system in which a guest operating system runs on a virtual machine of a virtualized computer system, a computer-implemented method of providing the guest operating system with direct access to a hardware device coupled to the virtualized computer system via a communication interface, the method including: (a) obtaining first configuration register information corresponding to the hardware device, the hardware device connected to the virtualized computer system via the communication interface; (b) creating a passthrough device by copying at least part of the first configuration register information to generate second configuration register information corresponding to the passthrough device; and (c) enabling the guest operating system to directly access the hardware device corresponding to the passthrough device by providing access to the second configuration register information of the passthrough device. | 01-09-2014 |
20140032767 | VIRTUAL MACHINE MIGRATION - A source virtual machine (VM) hosted on a source server is migrated to a destination VM on a destination server without first powering down the source VM. After optional pre-copying of the source VM's memory to the destination VM, the source VM is suspended and its non-memory state is transferred to the destination VM; the destination VM is then resumed from the transferred state. The source VM memory is either paged into the destination VM on demand, or is transferred asynchronously by pre-copying and write-protecting the source VM memory, and then later transferring only the modified pages after the destination VM is resumed. The source and destination servers preferably share common storage, in which the source VM's virtual disk is stored; this avoids the need to transfer the virtual disk contents. | 01-30-2014 |
20140040408 | SELECTING A MASTER NODE USING A SUITABILITY VALUE - Selecting a master node in a group of computing nodes. Computing nodes exchange suitability messages, candidate messages, and master messages to indicate the state of each node. A deterministic algorithm based on scores and timings is executed by each computing node to encourage each node to select the same master node. | 02-06-2014 |
20140137104 | Cooperative Application Workload Scheduling for a Consolidated Virtual Environment - Application resource scheduler module is provided to achieve cooperative application workload scheduling for a consolidated virtual environment. The application resource scheduler aids an application workload scheduler that is part of a distributed computing application, such as Hadoop, to achieve a specified relative priority of the application workload virtual machines to other virtual machines in the virtual environment. The application resource scheduler assists in achieving cooperative workload scheduling by revising the amount of resources that the application workload scheduler sees as available and by setting resource controls for the virtual machines of the distributed computing application to influence the resources the virtual machines receive from the underlying consolidated virtual environment. | 05-15-2014 |
20140149792 | METHOD AND SYSTEM FOR FREQUENT CHECKPOINTING - A virtualization platform provides fault tolerance for a primary virtual machine by continuously transmitting checkpoint information of the primary virtual machine to a collector process, such as a backup virtual machine. When implemented on a hardware platform comprising a multi-processor that supports nested page tables, the virtualization platform leverages the nested page table support to quickly identify memory pages that have been modified between checkpoints. The backup virtual machine provides feedback information to assist the virtualization platform in identifying candidate memory pages for transmitting actual modifications to the memory pages rather than the entire memory page as part of the checkpoint information. The virtualization platform further maintains a modification history data structure to identify memory pages that can be transmitted simultaneous with the execution of the primary virtual machine rather than while the primary virtual machine has been stunned. | 05-29-2014 |
20150019827 | GENERATING AND USING CHECKPOINTS IN A VIRTUAL COMPUTER SYSTEM - To generate a checkpoint for a virtual machine (VM), first, while the VM is still running, a copy-on-write (COW) disk file is created pointing to a parent disk file that the VM is using. Next, the VM is stopped, the VM's memory is marked COW, the device state of the VM is saved to memory, the VM is switched to use the COW disk file, and the VM begins running again for substantially the remainder of the checkpoint generation. Next, the device state that was stored in memory and the unmodified VM memory pages are saved to a checkpoint file. Also, a copy may be made of the parent disk file for retention as part of the checkpoint, or the original parent disk file may be retained as part of the checkpoint. If a copy of the parent disk file was made, then the COW disk file may be committed to the original parent disk file. | 01-15-2015 |
20150089272 | MAINTAINING HIGH AVAILABILITY OF A GROUP OF VIRTUAL MACHINES USING HEARTBEAT MESSAGES - Embodiments maintain high availability of software application instances in a fault domain. Subordinate hosts are monitored by a master host. The subordinate hosts publish heartbeats via a network and datastores. Based at least in part on the published heartbeats, the master host determines the status of each subordinate host, distinguishing between subordinate hosts that are entirely inoperative and subordinate hosts that are operative but partitioned (e.g., unreachable via the network). The master host may restart software application instances, such as virtual machines, that are executed by inoperative subordinate hosts or that cease executing on partitioned subordinate hosts. | 03-26-2015 |