Sun Microsystems, Inc.

Vmware, Inc.

Oracle America, Inc.

Cloud Physics, Inc.

Alexander T Garthwaite

Yury Baskakov

Carl Alan Waldspurger

David L Detlefs

Rajesh Venkatasubramanian

Ole Agesen

David Dice

Asit Desai

Antonios Printezis

Sunil Satnur

Jesse Pool

Derek Uluski

Ilya Languev

Irfan Ahmad

Kiran Tati

Irene Zhang

Guy Lewis Steele, Jr

Christine H Flood

Paul A Martin

Nohhyun Park

Kapil Arya

Mark S Moir

Nir N Shavit

Timothy Lawrence Harris

Steven K Heller

Puneet Zaroo

Kevin Scott Christopher

Vivek Pandey

Seongbeom Kim

Anoop Jaishankar

Raveesh Ahuja

Nikhil Bhatia

Maxime Austruy

Peter B Kessler

David P Stoutamire

Ishan Banerjee

Jon A Masamitsu

Tongping Liu

Y Srinivas Ramakrishna

Pin Lu

John W Coomes

Tan Li

Derek R White

Y Srinivas Ramakrisha

System and method for managing space in storage object structures stored in a storage system uses an object B tree structure to manage a storage object in a storage object structure in the storage system, which provides virtual physical block addresses for data of the storage object and for metadata of nodes of the object B tree structure. The metadata of the nodes of the object B tree structure is written in the storage object structure using first real physical block addresses, which are translated from the virtual block addresses for the metadata of the nodes of the object B tree structure using a metadata system file B tree structure. The data of the storage object is written in the storage object structure using second real physical block addresses, which are translated from the virtual block addresses for the data of the storage object using a data system file B tree structure.

System and method for managing space in storage object structures

System and method for creating group snapshots of multiple storage objects uses storage structures to store the storage objects in a storage system. In order to create a group snapshot of storage objects, a prepare snapshot process is executed at each of multiple host computers managing the storage objects as storage structures to block input and output operations on the storage objects stored in the storage structures. A commit snapshot process is then executed at each of the multiple host computers to create snapshots of the storage object in the respective storage structures. In addition, the snapshots of the storage object are recorded in the respective storage structures as snapshot entries in the respective storage structures.

System and method for creating group snapshots

System and method for creating linked clones of storage objects stored in a storage uses a target storage structure that includes a linked clone being created from a selected snapshot of a storage object and surface snapshots. The linked clone is created in the target storage structure with references to the selected snapshot of the storage object in a source storage structure without completely copying the selected snapshot to the target storage structure. The surface snapshots, which correspond to other snapshots of the storage object in the source storage structure, are created in the target storage structure with references to the other snapshots without completely copying the other snapshots to the target storage structure to produce the linked clone with similar snapshots as the storage object at a point in time when the selected snapshot was captured.

System and method for creating linked clones of storage objects with surface snapshots

System and method for managing different types of snapshots of storage objects stored in a storage system uses a storage structure that includes both a storage object and any snapshots of the storage object. When a request to delete a snapshot of the storage object is received, a determination is made whether the snapshot is a first snapshot type. After determining that the snapshot is not the first snapshot type, the snapshot is deleted from the storage structure. After determining that the snapshot is the first snapshot type, the snapshot is marked as delete designated, and a deletion of the snapshot from the storage structure is prevented when there is a second snapshot type snapshot remaining in the storage structure that was created after the snapshot had been created so that the snapshot is available when the second snapshot type snapshot is subsequently used.

System and method for managing different types of snapshots of storage objects

System and method for managing snapshots of storage objects stored in a storage system uses a storage structure that includes both a storage object and any snapshots of the storage object. When a request to delete the storage object is received, the storage structure that includes the storage object is checked to determine if there is at least one snapshot in the storage structure. After determining that there is at least one snapshot in the storage structure, the storage object is marked as being delete designated without deleting the storage structure. After determining that there is no snapshot in the storage structure, the storage structure is deleted.

System and method for managing snapshots of storage objects for snapshot deletions

One or more embodiments provide techniques for accessing a memory page of a virtual machine for which loading might have been deferred, according to an embodiment of the invention, includes the steps of examining metadata of the memory page and determining that a flag in the metadata for indicating that the contents of the memory page needs to be updated is set, and updating the contents of the memory page.

Method for improving memory system performance in virtual machine systems

In a virtualized computer system, guest memory pages are mapped to disk blocks that contain identical contents and the mapping is used to improve management processes performed on virtual machines, such as live migration and snapshots. These processes are performed with less data being transferred because the mapping data of those guest memory pages that have identical content stored on disk are transmitted instead of the their contents. As a result, live migration and snapshots can be carried out more quickly. The mapping of the guest memory pages to disk blocks can also be used to optimize other tasks, such as page swaps and memory error corrections.

Mapping guest pages to disk blocks to improve virtual machine management processes

Memory performance in a computer system that implements large page mapping is improved even when memory is scarce by identifying page sharing opportunities within the large pages at the granularity of small pages and breaking up the large pages so that small pages within the large page can be freed up through page sharing. In addition, the number of small page sharing opportunities within the large pages can be used to estimate the total amount of memory that could be reclaimed through page sharing.

Identification of page sharing opportunities within large pages

The configuration of a cache is adjusted within a computer system that includes at least one entity that submits a stream of references, each reference corresponding to a location identifier corresponding to data storage locations in a storage system. The reference stream is spatially sampled using reference hashing. Cache utility values are determined for each of a plurality of caching simulations and an optimal configuration is selected based on the results of the simulations.

Dynamic cache allocation adjustment using multiple cache simulations for efficient cache utility curve construction

Updating contents of certain memory pages in a virtual machine system is deferred until they are needed. Specifically, certain page update operations are deferred until the page is accessed for a load or store operation. Each page within the virtual machine system includes associated metadata, which includes a page signature characterizing the contents of a corresponding page or a reference to a page with canonical contents, and a flag that indicates the page needs to be updated before being accessed. The metadata may also include a flag to indicate that a backing store of the memory page has contents of a known content class. When such a memory page is mapped to a shared page with contents of that known content class, a flag in the metadata to indicate that contents of the memory page needs to be updated is not set.

Interaction is evaluated between a computer system cache and at least one entity that submits a stream of references corresponding to location identifiers of data storage locations. The reference stream is spatially sampled by comparing a hash value of each reference with a threshold value and selecting only those references whose hash value meets a selection criterion. Cache utility values are then compiled for those references. In some embodiments, the compiled cache values may then be corrected for accuracy as a function of statistics of those location identifiers over the entire stream of references and of the sampled references whose hash values satisfied the selection criterion. Alternatively, a plurality of caching configurations is selected and the selected references are applied as inputs to a plurality of caching simulations, each corresponding to a different caching configuration. A resulting set of cache utility values is then computed for each caching simulation.

System and method for efficient cache utility curve construction and cache allocation

Cache utility curves are determined for different software entities depending on how frequently their storage access requests lead to cache hits or cache misses. Although possible, not all access requests need be tested, but rather only a sampled subset, determined by whether a hash value of each current storage location identifier (such as an address or block number) meets one or more sampling criteria. The sampling rate is adaptively changed so as to hold the number of location identifiers needed to be stored to compute the cache utility curves to within a set maximum limit.

Cache allocation system and method using a sampled cache utility curve in constant space

A computer implemented method for reducing the latency of an anticipated read of disk blocks from a swap file in a virtualized environment. The environment includes a host swap file maintained by a host operating system and a guest swap file maintained but a guest operating system. First, the method identifies a sequence of disk blocks that was written in the guest swap file. The method then detects within the sequence of blocks a first disk block that contains a reference to a second disk block that is stored in the host swap file. The method then replaces the first disk block in the guest swap file with the second disk block.

Techniques for reducing read I/O latency in virtual machines

A computer implemented method for reducing the latency of an anticipated read of disk blocks from a swap file in a virtualized environment. First, the method identifies a sequence of disk blocks that was written in a guest swap file. The method then detects a first reference within the sequence of blocks that references a first disk block stored in a host swap file and a second reference within the sequence of blocks that references a second disk block stored in the host swap file. The method then moves the second disk block to a location in a host swap file that is adjacent to the first disk block. In some examples, the first block and second block are both moved to a new location in the host swap file where they are adjacent to one another.

Growing community of inventors

Beverly, MA, United States of America

Alexander T Garthwaite