Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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 structure 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.

Abstract: 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.

Abstract: 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).

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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).

Abstract: 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.

Abstract: 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.

Abstract: 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.