Abstract: A technique for storing metadata changes includes caching metadata changes in a persistent metadata cache. The persistent metadata cache is configured to cache metadata reads and writes directed to a set of internal volumes of the data storage system. A file system can access pages of the persistent metadata cache by specifying an identifier of an internal volume and an offset into that volume to which the metadata changes are directed.

Abstract: A method, computer program product, and computing system for generating a first file system for use within a data storage array. A first temporary storage space is defined within the data storage array for use during a file system recovery event. The size of the first temporary storage space is defined based, at least in part, upon the actual utilization of the first file system.

Abstract: Techniques are described for allowing a data storage system to provision all vVols (or other similar virtual storage containers) as logical storage devices, which can be bound to either a block-based protocol endpoint as an exposed LUN or to a file-based protocol endpoint as a file. This may be accomplished by operating, as part of the file-based protocol endpoint, a lightweight filesystem that creates file abstractions that map to underlying logical storage devices.

Abstract: A technique manages host data in a data storage array. The technique involves placing, in response to host input/output (I/O) requests from a set of host devices, host data in a container file system which is stored in a slice pool of storage slices (e.g., storage space of a standard size such as 256 MB) formed by multiple storage tiers of the data storage array. Each storage tier provides storage access at a different storage access speed. The technique further involves assigning classifications to storage slices of the slice pool which store the container file system, each classification being assigned based on storage slice access history resulting from the host I/O requests. The technique further involves relocating portions of the container file system among the multiple storage tiers according to the classifications assigned to the storage slices of the slice pool.

Abstract: A technique forms contents of a deduplication container from a standalone container file system stored on the same data storage array on which the deduplication container is stored. Such a standalone container includes a container file which is formed by standalone blocks that are not shared with any other file within the standalone container outside of snapshots of that file. The standalone blocks store host data and which are hierarchically related to each other. Upon receiving a deduplication command, the storage processor carries out a set of deduplication operations which include creating and storing the deduplication container in the data storage array. The deduplication container includes container files which are formed by deduplication blocks storing the host data and which are hierarchically related to each other.

Abstract: A method is used in recovering from metadata inconsistencies in storage systems. A metadata inconsistency is detected in a portion of a file system. The file system is managed by upper-layer component. The portion of the file system is recovered. Lower-layer component recovers the portion of the file system. The portion of the file system is validated. The upper-layer component validates the portion of the file system.

Abstract: Managing a file system to avoid unnecessary replay of a transaction log. The file system may reside on a non-volatile storage medium having an associated transaction log residing on a non-volatile storage medium, the transaction log including a plurality of log entries, and each log entry representing one or more changes to metadata of the file system. The file system may include a first data structure including a status parameter, a value of which is indicative of whether to replay the transaction log when the file system is initialized. It may be determined whether the one or more changes to metadata represented by each of the plurality of log entries have been written in place in the file system. In response to the determination, the status parameter may be set to a value indicative of the determination.

Abstract: A technique for managing data storage operations in a data storage system having a file-based front end system and a block-based back end array includes provisioning a set of storage resources on the array for use exclusively with one or more virtualized storage processors (VSPs), where each VSP identifies multiple file systems. In response to a management command to perform a data storage operation on a VSP, the back-end array performs the specified operation on the provisioned set of storage resources. Thus, the back-end array performs the data operation exclusively on the VSP (or on multiple VSPs) and therefore on all of its constituent file systems as one.

Abstract: A method is used in managing data deduplication in storage systems based on storage space characteristics. Characteristics of first and second storage tiers are evaluated. A first data object resides on the first storage tier and a second data object resides on the second storage tier. The first and second data objects are selected for applying a deduplicating technique. A data storage system includes the first and second storage tiers configured such that performance characteristics associated with the first storage tier is different from the second storage tier. Based on the evaluation, the deduplicating technique is applied to the first and second data objects.

Abstract: A technique for storing data in a log receives a set of sequential requests, each request specifying data to be written to a data object served by a data storage system. The data specified by respective ones of the requests is placed into respective lockable units of storage for the log, such that the data of no two sequential requests are stored within the same lockable unit. Each lockable unit is locked for access by a writer when being written, and unlocked when not being written, and is configured to store data specified by multiple requests. Completion of each of the requests is acknowledged in response to placing the data specified by the respective request in one of the lockable units of storage. The log may also be partitioned, with individual partitions being used to store data specified by requests having specific request sizes.

Abstract: A technique provides mobility to VSPs. The technique involves receiving, by processing circuitry, a VSP move command from a user. The VSP move command specifies a source VSP and a destination. The technique further involves identifying, by the processing circuitry and in response to the VSP move command, multiple source data objects which are configured to store data from the context of the source VSP. The multiple source data objects reside in a source storage pool. The technique further involves, after the multiple source data objects are identified, transforming the multiple source data objects into multiple destination data objects which are configured to store data from the context of a destination VSP at the destination. The multiple destination data objects reside in a destination storage pool which is different from the source storage pool. Such operation effectively provides VSP migration from source to destination.

Abstract: A multi-core processor of a network attached storage system processes requests from host computers for services of a file system service. Each core maintains endpoints of respective connection-layer connections to the hosts to affine respective streams of network traffic with the core, and dynamically and preferentially assigns execution threads of the core to process file system service requests of the streams affined with the core. Each core also co-operates with the other cores to dynamically and non-preferentially (a) assign execution threads of the core to process file system service requests of the streams affined with the other cores, and (b) assign execution threads of the other cores to process file system service requests of the streams affined with the core, promoting efficient use of the cores for the processing workload of the file system service.

Abstract: A method is used in managing file system checking in file systems. Metadata of a file system is evaluated upon receiving a request to perform file system checking on the file system. Based on the evaluation, determination is made as to whether file system checking has been performed previously on the file system. Based on the determination, file system checking is performed on the file system.

Abstract: A method, computer program product, and computing system for defining an initial root slice for a storage system. A first data slice is defined for the storage system. The location of the first data slice of the storage system is identified within the initial root slice. A request for a supplement data slice within the storage system is received. A determination is made as to if the supplement data slice can be added within the storage system without defining a supplemental root slice for a storage system.

Abstract: A method is used in recovering file mapping information in file systems. Metadata of a file of a file system is evaluated. Mapping information associating the file to a file system hierarchy of the file system is missing a reference to an inode of the file. Based on the evaluation, the mapping information is updated for including the file to the file system hierarchy of the file system.

Abstract: A technique is used for optimizing data location in data storage arrays. A primary storage array is associated with a secondary storage array, the primary storage array and secondary storage array including auto-tiering functionality, where the secondary storage array is configured as a backup storage array for the primary storage array. Tiering metadata is derived for a storage object stored on the primary storage array. The tiering metadata is transmitted to the secondary storage array. Auto-tiering is initiated at the secondary storage array, where the received tiering metadata is provided as input to the secondary storage array's auto-tiering function when auto-tiering replicated storage object associated with the tiering metadata.

Abstract: A method is used in managing updating of metadata of file systems. A reference to a change to metadata of a file of a file system is stored in a global sync list configured to store changes to metadata of a plurality of files of a plurality of file systems. The change to the metadata of the file is stored in a journal upon receiving an I/O request for the file of the file system. The journal includes metadata transactions upon the plurality of files of the plurality of the file system. The change to the metadata of the file of the file system is applied to metadata of the file system organized on a storage device using the reference to the change stored in the global sync list.

Abstract: A method is used in managing data deduplication in storage systems based on I/O activities. I/O activity of first and second data objects is evaluated. The first and second data objects are selected for applying a deduplicating technique. Based on the evaluation, the deduplicating technique is applied to the first and second data objects.

Abstract: A technique for supporting failover between SPs at different physical sites includes operating a distributed data manager (DDM) in an IO stack of both a first SP at a first site and a second SP at a second site. The DDMs of the first and second SPs cooperatively function to provide LUN virtualization that preserves virtual LUN IDs such that the first SP and the second SP can each access the same virtualized LUNs using the same virtual LUN IDs. In the event of a failure at the first site, the second SP at the second site may access the virtualized LUNs originally accessed by the first SP, including those storing configuration and site-specific data for the first site, as if those LUNs were local to the second SP.

Abstract: A method is used in managing delete operations in files of file systems. An indirect data block of a file of a file system is deleted. A parent indirect data block pointing to the indirect data block is removed from a list. The parent indirect data block has been added to the list for flushing contents of the parent indirect data block to a storage device.