Vmware, Inc.

Vmwre, Inc.

Dart Neuroscience, LLC

Bryan Branstetter

Asit Desai

Prasanna Aithal

Prasad Rao Jangam

Pradeep H Krishnamurthy

Mahesh Shivanagouda Hiregoudar

Srinivasa Shantharam

Rohan Pasalkar

Raghavan Pichai

Laurent Gomez

Brian Dyck

James Breitenbucher

Andrew Richard Hudson

Troy Vickers

Michael I Weinhouse

Marco Peters

Tami Jo Marrone

Amy Allan

Vivek Patidar

Tammi Jo Marrone

Methods, systems, and apparatus, including computer programs encoded on a computer storage medium, for reclaiming one or more portions of storage resources in a computer system serving one or more virtual computing instances, where the storage resources in the computer system are organized in clusters of storage blocks. In one aspect, a method includes maintaining a respective block tracking value for each storage block that indicates whether a call to reclaim the storage block is outstanding; determining, from the block tracking values, a respective cluster priority value for each of the clusters based on a count of storage blocks in the respective cluster for which a call to reclaim is outstanding; and reclaiming a first portion of storage resources in the computer system in accordance with the cluster priority values.

Reclaiming storage resources

The systems described herein are configured to enhance the efficiency of memory usage and access in a VM file system data store with respect to allocating memory in large and small file block clusters using affinity metadata and propagating and maintaining the affinity metadata in support of the described allocation. In order to maintain affinity metadata of the large file block cluster, affinity generation values stored on the large file block cluster are read and cached affinity generation values for each small file block cluster are read from an in-memory cache associated with the large file block cluster. When the stored affinity generation values and the cached affinity generation values do not match, affinity metadata from all the small file block clusters associated with the large file block cluster is used to update the affinity metadata of the large file block cluster and the associated cache.

Propagating affinity data to large file block clusters in a file system

Techniques for decoupling the commit and replay of file system metadata updates in a clustered file system (CFS) are provided. In one embodiment, a CFS layer of a computer system can receive a file I/O operation from a client application, where the file I/O operation involves an update to a file system metadata resource maintained on persistent storage. In response, a journaling component of the CFS layer can execute a commit phase for committing the update to a journal on the persistent storage. The CFS layer can then return an acknowledgment to the client application indicating that the file I/O operation is complete, where the acknowledgement is returned prior to completion of a replay phase configured to propagate the update from the journal to one or more locations on the persistent storage where the file system metadata resource is actually stored.

Decoupling the commit and replay of metadata updates in a clustered file system

The systems described herein are configured to enhance the efficiency of memory usage and access in a VM file system data store with respect to allocating memory in large and small file block clusters using affinity metadata and propagating and maintaining the affinity metadata in support of the described allocation. During storage of file data, an affinity identifier of the file data is determined. The affinity identifier is used to identify a large file block cluster and a small file block cluster within the identified large file block cluster. The file data is stored in the selected small file block cluster and affinity metadata of the selected small file block cluster is updated to reflect the storage of the file data.

Allocating memory resources in a file system based on affinity data

A distributed file system may be configured with file blocks of a first type and file blocks of a second type, from allocation units that comprise a logical volume containing the file system. File blocks of the second type may be defined from one or more file blocks of the first type. A thick file may be instantiated with a number of allocation units totaling a size greater than or equal to a specified file size of the thick file. The allocation units may be allocated to the thick file in units of file blocks of the first type or file blocks of the second type, depending on the specified file size of the thick file.

Method and system for thick files in a distributed file system

Exemplary methods, apparatuses, and systems determine whether a skip optimization process can be used to store a file in a storage space. When it is determined that the skip optimization can be performed, a file stored in the storage space can be referenced in a file metadata data structure using direct addressing of file blocks storing the file instead of through indirect addressing (e.g., pointer addresses stored in pointer blocks).

Minimizing file creation and access times using skip optimization

The systems described herein are configured to enhance the efficiency of memory in a host file system with respect to hosted virtual file systems. In situations when the hosted virtual file systems use smaller file block sizes than the file block sizes of the host file system. During storage of a file, a file block is assigned a block address and unmapping bits. The block address and unmapping bits are stored in a pointer block or other similar data structure associated with the file. Particularly, the block address is stored in a first address block and the unmapping bits are stored in at least one additional address block located in proximity to the block address, such that the unmap granularity of the file is not limited by the fixed size of address blocks in the system.

Granular unmapping with variable addressing in a data store

System and method for executing a file system operation for a computer system utilize a computed hash value of a file system object to access a hash block of a file system directory stored in a storage system to locate a hash slot corresponding to the computed hash value. Using at least one of a hash pointer in the hash slot and an allocation block of the file system directory, a dirent slot in a dirent block of the file system directory is located to perform an operational task on the particular dirent slot to execute the file system operation.

Growing community of inventors

Palo Alto, CA, United States of America

Bryan Branstetter