Abstract: A method facilitating an update to a file system comprises storing a set of transaction log entries at log space of a storage log associated with the file system, the transaction log entries comprising instructions for fulfilling a set of transactions that define change to the file system, assigning, in an ordered sequence corresponding to a sequence order of journalling of the set of transaction log entries to the log space, transaction markers to a set of transaction marker lists, wherein the transaction markers reference the set of transaction log entries, and, for individual transaction markers of the transaction markers, preventing reuse of the log space corresponding thereto until an evaluation of the set of transaction marker lists results in a determination that writing of all modified system metadata corresponding thereto has been executed and that the transaction marker is set equal to a global head transitioning the transaction markers.

Abstract: Migration of information, comprising inode numbers, from source filesystem to destination filesystem can be performed and managed. Migrator component can partition inode subspace of destination filesystem into first inode subspace region, comprising first subgroup of inode slices, and second inode subspace region, comprising second subgroup of inode slices. Provisioner manager component can provision first inode slices of the first subgroup in a first order. Inode numbers associated with user files or directories contained in source slices of the source filesystem can be migrated to and allocated for corresponding first inode slices of the destination filesystem. Provisioner manager component can provision second inode slices of the second subgroup in a second order that can be different from the first order. Inodes associated with inode numbers associated with internal files or directories can be stored in the second inode slices. Source filesystem can be active during the migration process.

Abstract: A method facilitating an update to a file system comprises storing a set of transaction log entries at log space of a storage log associated with the file system, the transaction log entries comprising instructions for fulfilling a set of transactions that define change to the file system, assigning, in an ordered sequence corresponding to a sequence order of journalling of the set of transaction log entries to the log space, transaction markers to a set of transaction marker lists, wherein the transaction markers reference the set of transaction log entries, and, for individual transaction markers of the transaction markers, preventing reuse of the log space corresponding thereto until an evaluation of the set of transaction marker lists results in a determination that writing of all modified system metadata corresponding thereto has been executed and that the transaction marker is set equal to a global head transitioning the transaction markers.

Abstract: Described is technology that facilitates journalling a transaction log entry to chunks of storage while allowing for obtaining of modified system metadata associated therewith in the case of a computing device issue. An associated method comprises at least storing, by a system operatively coupled to a processor, a set of transaction log entries at log space of a storage log associated with a file system, wherein the transaction log entries comprise instructions for fulfilling a set of transactions, and wherein the transactions define changes to the file system, generating a checkpoint marker corresponding to a set of log storage objects of the storage log at which the transaction log entries are stored, and based on the checkpoint marker, preventing, by the system, reuse of the log space until writing of all modified system metadata corresponding to the transaction log entries has been executed.

Abstract: The technology described herein efficiently determines whether a real inode is shared among views, or owned. In-memory data structures include a view snapshot generation counter that is increased as a snapshot that generates a view is created, and an inode total weight. An in-memory virtual inode cache dataset for a filesystem object associated with the view is instantiated with the value of snapshot generation counter, sharing-related data based on the inode mapping file entry for the object, and an inode access weight. To determine whether the inode is shared (and needs to be split), such as on a write to the object, the in-memory data is evaluated. The real inode is shared if the generation counters are unequal, if the sharing-related data indicates sharing at an intermediate indirect block level, or indicates sharing at the inode level and the inode access weight is less than the inode total weight.

Abstract: Technology described herein can perform deletion of a snapshot or portion thereof. In an embodiment, a system can comprise a processor and a memory that stores executable instructions that, when executed by the processor, facilitate performance of operations. The operations can comprise, to delete a snapshot, or a portion of a snapshot, of a real filesystem, reading an inode mapping file (IMF) of the snapshot that indexes a virtual inode number (VIN) corresponding to a real inode. The operations further can comprise identifying the real inode of the snapshot referenced by the VIN, identifying a file object corresponding to the real inode, and deleting the file object from the snapshot.

Abstract: Optimizing file system resource reservation is presented herein. The method comprises dividing a virtual file system address space into subspaces, initializing the subspaces with volume slices of a group of volume slices comprising a first volume slice, a second volume slice, and a collection of reserved volume slices allocated based on an allocation pattern that allocates volume slices as a function of a quantitative relationship between a first value associated with a first volume slice and a second value associated with a second volume slice, determining that a data block count is insufficient to service a write operation of user data to the second volume slice; and provisioning a second subspace with a free volume slice obtained from the collection of reserved volume slices, and wherein the provisioning of the second subspace with the free volume slice is performed without invoking a memory exclusion mechanism.

Abstract: Optimizing file system resource reservation is presented herein. The method comprises dividing a virtual file system address space into subspaces, initializing the subspaces with volume slices of a group of volume slices comprising a first volume slice, a second volume slice, and a collection of reserved volume slices allocated based on an allocation pattern that allocates volume slices as a function of a quantitative relationship between a first value associated with a first volume slice and a second value associated with a second volume slice, determining that a data block count is insufficient to service a write operation of user data to the second volume slice; and provisioning a second subspace with a free volume slice obtained from the collection of reserved volume slices, and wherein the provisioning of the second subspace with the free volume slice is performed without invoking a memory exclusion mechanism.

Abstract: Technology described herein can perform deletion of a snapshot or portion thereof. In an embodiment, a system can comprise a processor and a memory that stores executable instructions that, when executed by the processor, facilitate performance of operations. The operations can comprise, to delete a snapshot, or a portion of a snapshot, of a real filesystem, reading an inode mapping file (IMF) of the snapshot that indexes a virtual inode number (VIN) corresponding to a real inode. The operations further can comprise identifying the real inode of the snapshot referenced by the VIN, identifying a file object corresponding to the real inode, and deleting the file object from the snapshot.

Abstract: The technology described herein efficiently determines whether a real inode is shared among views, or owned. In-memory data structures include a view snapshot generation counter that is increased as a snapshot that generates a view is created, and an inode total weight. An in-memory virtual inode cache dataset for a filesystem object associated with the view is instantiated with the value of snapshot generation counter, sharing-related data based on the inode mapping file entry for the object, and an inode access weight. To determine whether the inode is shared (and needs to be split), such as on a write to the object, the in-memory data is evaluated. The real inode is shared if the generation counters are unequal, if the sharing-related data indicates sharing at an intermediate indirect block level, or indicates sharing at the inode level and the inode access weight is less than the inode total weight.

Abstract: Techniques for limiting storage consumed by a file system without shrinking a volume upon which the file system is deployed. The techniques are employed in a clustered environment including multiple NAS nodes, each having access to block storage including multiple storage devices. By deploying the file system on a volume of a NAS node within the clustered environment, setting the value of the FS user size to be equal to the FS volume size, and if, at a later time, it is desired to reduce the file system size, setting the value of the FS user size to a lesser value than the FS volume size, IO requests received at the NAS node can be satisfied within the logical limit of the lesser value of the FS user size without shrinking the local volume, allowing the file system size to be reduced without requiring close coordination with the block storage.

Abstract: Techniques for limiting storage consumed by a file system without shrinking a volume upon which the file system is deployed. The techniques are employed in a clustered environment including multiple NAS nodes, each having access to block storage including multiple storage devices. By deploying the file system on a volume of a NAS node within the clustered environment, setting the value of the FS user size to be equal to the FS volume size, and if, at a later time, it is desired to reduce the file system size, setting the value of the FS user size to a lesser value than the FS volume size, IO requests received at the NAS node can be satisfied within the logical limit of the lesser value of the FS user size without shrinking the local volume, allowing the file system size to be reduced without requiring close coordination with the block storage.

Abstract: Described are methods, systems, and apparatus, including computer program products for de-duplicating access control lists (ACLs). A first ACL associated with a first computer file is received. A first checksum based at least in part on the first ACL is calculated. One or more directory entries based on the first checksum are retrieved from a de-duplication directory, wherein each directory entry of the one or more directory entries comprises a reference to an ACL and a name comprising the first checksum. A directory entry of the one or more directory entries is identified that references a second ACL that specifies the same permissions as the first ACL. A reference to the second ACL of the directory entry is added to the first computer file.

Abstract: A method, computer program product, and computing system for grouping storage blocks within a file system into a plurality of storage pools including a free-backed storage pool, a free-unbacked storage pool, and an allocated-backed storage pool. The free-backed storage pool identifies unused storage blocks within the file system that are already associated with physical storage space within a backend storage system. The free-unbacked storage pool identifies unused storage blocks within the file system that are not yet associated with physical storage space within the backend storage system. The allocated-backed storage pool identifies used storage blocks within the file system that are already associated with physical storage space within the backend storage system. A request is received for one or more unused storage blocks within the file system.

Abstract: This invention is a system and a method for operating a storage server in a data network using a new architecture. The method of creating the partial block map allows the snapshot writes on a direct mapped file. The method of reading data or writing data to the file created in direct mapping state and later converted to partial mapping state responsive to a copy on first write request by a client allocates new indirect block when needed to store the reference to newly allocated data block. The method of reading data from or writing data to the file in partial mapping state involves checking the mapping bit to find if the indirect block is in direct mapping state.

Abstract: A self healing file system is designed for proactive detection and containment of faults, errors, and corruptions, in order to enable in place (online) and non-intrusive recovery. For proactive fault detection, the file system maintains certain per-block metadata of each file system block. The per-block metadata includes a redundancy check, and for file system data blocks, an inode identifier, and an offset of the file system data block in the file including the file system data block. The redundancy check is used to detect and mark bad file system blocks. The inode identifier and offset is used for validating connectivity of the file system blocks to the inodes, and for tracing bad blocks to files that contain the bad blocks.

Abstract: A container file system is built on a sparse metavolume for enhanced decoupling of logical storage from physical storage and for providing common supplementary storage services for iSCSI block access and for NFS or CIFS file system access. The container file system contains a production file system or iSCSI LUN and may also contain snapshot copies of the production file system or iSCSI LUN. The container file system manages storage space among the production file system or iSCSI LUN and its snapshot copies, and also improves fault containment. The sparse metavolume provides thin provisioning of the container file system. A slice map indicates whether or not each slice of logical storage in the sparse metavolume is provisioned with an associated configured slice of data storage.