Vmware, Inc.

Datrium, Inc.

Datrium, Linc.

Ganesh Venkitachalam

Boris Weissman

Vyacheslav Vladimirovich Malyugin

Min Xu

Daniel J Scales

Michael Nelson

R Hugo Patterson, Iii

Jeffrey W Sheldon

Sazzala Reddy

Pratap Subrahmanyam

Garrett Cale Smith

Rohit Jain

Alexander Klaiber

Feng Tian

Aleksandr Mirgorodskiy

Brian Biles

Lakshmi Narayanan Bairavasundaram

Petr Vandrovec

Nitin Garg

Vijayan Prabhakaran

Vasudevan Sangili

Alex Mirgorodsky

R Hugo Patterson

James Eugene Chow

Michael Cohen

Alexander Moshchuk

Dmitry Grinberg

Andrew Biggadike

R Hugo Patterson Iii

System and method for providing fault tolerance in virtualized computer systems use a first guest and a second guest running on virtualization software to produce outputs, which are produced when a workload is executed on the first and second guests. An output of the second guest is compared with an output of the first guest to determine if there is an output match. If there is no output match, the first guest is paused and a resynchronization of the second guest is executed to restore a checkpointed state of the first guest on the second guest. After the resynchronization of the second guest, the paused first guest is caused to resume operation.

Virtual machine fault tolerance

Data in a storage system is deduplicated after receiving from at least one writing entity requests for a plurality of write operations for a corresponding plurality of data blocks in a storage object. The received blocks are buffered and sorted in order and a sequence of clumps is created from the buffered blocks, where each clump comprises a grouping of at least one of the sorted, buffered blocks. A boundary is determined between at least one pair of clumps based at least in part on the content of at least one of the buffered blocks, and it is then determined whether at least one of the clumps is a duplicate of a previously stored clump.

System and methods for storage data deduplication

A data storage system includes a plurality of hosts, each of which includes at least one processor and communicates over a network with a plurality of storage nodes, at least one of which has at least one storage device, at least one storage controller, and at least one non-volatile memory. At least one process within a host issues data storage read/write requests. At least one of the hosts has a cache for caching data stored in at least one of the plurality of storage nodes. The host writes data corresponding to a write request to at least one remote non-volatile memory and carries out at least one storage processing function; data in the written-to node may then be made available for subsequent reading by a different one of the hosts. Examples of the storage processing function include compression, ECC computation, deduplicating, garbage collection, write logging, reconstruction, rebalancing, and scrubbing.

Data storage with a distributed virtual array

In a computer system running at least a first virtual machine (VM) and a second VM on virtualization software, a computer implemented method for the second VM to provide quasi-lockstep fault tolerance for the first VM includes executing a workload on the first VM and the second VM that involves producing at least one externally visible output and comparing an externally visible output of the second VM with an externally visible output of the first VM to determine if there is an output match. In response to a determination that the externally visible output of the second VM does not match the externally visible output of the first VM, a resynchronization of the second VM is executed. The externally visible output of the first VM is kept from being output externally until completion of the resynchronization.

The output of a non-deterministic instruction is handled during record and replay in a virtual machine. An output of a non-deterministic instruction is stored to a buffer during record mode and retrieved from a buffer during replay mode without exiting to the hypervisor. At least part of the contents of the buffer can be stored to a log when the buffer is full during record mode, and the buffer can be replenished from a log when the buffer is empty during replay mode.

Efficient recording and replaying of non-deterministic instructions in a virtual machine and CPU therefor

A data storage system has a plurality of hosts that request writes of data to a relatively high-performance storage device (RHPSD) such as NVRAM, which may be one of a plurality of RHPSDs in a plurality of storage nodes. A storage management system receives the write requests and writes received data to the RHPSD. According to an allocation policy, the storage management system indicates to at least one of the hosts that it should limit its use of RHPSD and it then discards data upon indication from that host to do so. Before being discarded from the RHPSD, the data may be written to a persistent storage device.

System and method for managing a non-volatile storage resource as a shared resource in a distributed system

A data storage system includes a plurality of hosts, each of which includes at least one processor and communicates over a network with a plurality of storage nodes, at least one of which has at least one storage device, at least one storage controller, and at least one non-volatile memory. At least one process within a host issues data storage read/write requests. At least one of the hosts has a cache for caching data stored in at least one of the storage nodes. The host writes data corresponding to a write request to at least one remote non-volatile memory and carries out at least one storage processing function; data in the written-to node may then be made available for subsequent reading by a different one of the hosts. Examples of the storage processing function include compression, ECC computation, deduplicating, garbage collection, write logging, reconstruction, rebalancing, and scrubbing.

Embodiments of a distributed virtual array data storage system and method are disclosed. Storage nodes made up of relatively unsophisticated disks with associated processors are scalable to store very large amounts of data. The storage nodes communicate with servers directly over a network through, for example, an Ethernet connection. Control of the storage nodes and access to the storage nodes is handled entirely on the server side of the system by distributed virtual array (DVA) software running on the server side and employing a particular protocol over the standard network connection. In an embodiment, server-side virtual machine (VM) hosts host application VMs that are associated with vDisks. The DVA software distributes data for the vDisk over the storage nodes. In the case of failure of one or more of the storage nodes, the DVA software reconstructs the data, for example by reading redundant data from surviving storage nodes.

Distributed virtual array data storage system and method

The translation lookaside buffer (TLB) of a processor is kept in synchronization with a guest page table by use of an indicator referred to as a 'T' bit. The T bit of the NPT/EPT entries mapping the guest page table are set when a page walk is performed on the NPT/EPT. When modifications are made to pages mapped by NPT/EPT entries with their T bit set, changes to the TLB are made so that the TLB remains in synchronization with the guest page table. Accordingly, record/replay of virtual machines of virtualized computer systems may be performed reliably with no non-determinism introduced by stale TLBs that fall out of synchronization with the guest page table.

Synchronizing a translation lookaside buffer with page tables

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.

Method and system for frequent checkpointing

In a computer system running at least a first virtual machine (VM) and a second VM on virtualization software, a computer implemented method for the second VM to provide quasi-lockstep fault tolerance for the first VM. The method includes enabling operations of the second VM to diverge from being in lockstep with operations with the first VM without resynchronizing the second VM with the first VM, if output of the second VM is not diverging from output of the first VM. The output of the second VM is compared with the output of the first VM to determine whether the output of the second VM has diverged from the output of the first VM. In response to a determination that the output of the second VM has diverged from the output of the first VM, a resynchronization of the second VM is executed.

Growing community of inventors

Mountain View, CA, United States of America

Ganesh Venkitachalam