Abstract: Technologies for a transistor with a thin-film ferroelectric gate dielectric are disclosed. In the illustrative embodiment, a transistor has a thin layer of scandium aluminum nitride (ScxAl1-xN) ferroelectric gate dielectric. The channel of the transistor may be, e.g., gallium nitride or molybdenum disulfide. In one embodiment, the ferroelectric polarization changes when voltage is applied and removed from a gate electrode, facilitating switching of the transistor at a lower applied voltage. In another embodiment, the ferroelectric polarization of a gate dielectric of a transistor changes when the voltage is past a positive threshold value or a negative threshold value. Such a transistor can be used as a one-transistor memory cell.

Abstract: Data integrity is maintained during failed communications between a member node of a primary cluster and a backup cluster by assigning an assisting member node to run an assisting process that transmits data entered into the member node to the backup cluster. In this way, a replicated database is maintained during a partial communication failure between the primary cluster and the backup cluster.

Abstract: Data integrity is maintained during failed communications between a member node of a primary cluster and a backup cluster by assigning an assisting member node to run an assisting process that transmits data entered into the member node to the backup cluster. In this way, a replicated database is maintained during a partial communication failure between the primary cluster and the backup cluster.

Abstract: Data integrity is maintained during failed communications between a member node of a primary cluster and a backup cluster by assigning an assisting member node to run an assisting process that transmits data entered into the member node to the backup cluster. In this way, a replicated database is maintained during a partial communication failure between the primary cluster and the backup cluster.

Abstract: Data integrity is maintained during failed communications between a member node of a primary cluster and a backup cluster by assigning an assisting member node to run an assisting process that transmits data entered into the member node to the backup cluster. In this way, a replicated database is maintained during a partial communication failure between the primary cluster and the backup cluster.

Abstract: There is provided, in a computer processing system, an apparatus for managing object data. The apparatus includes a changed objects manager for creating and managing a changed objects list that at least identifies the objects that have changed based on time of change. The changed objects list is associated with a plurality of time buckets. Each of the plurality of time buckets is associated with a respective date and time period and with object change records for objects having a timestamp falling within the respective date and time period. Each of the object change records is associated with a unique object identifier and the timestamp for a corresponding one of the objects. The timestamp specifies a date and a time corresponding to a latest one of a creation time or a most recent update time for the corresponding one of the objects.

Abstract: There is provided, in a computer processing system, an apparatus for managing object data. The apparatus includes a changed objects manager for creating and managing a changed objects list that at least identifies the objects that have changed based on time of change. The changed objects list is associated with a plurality of time buckets. Each of the plurality of time buckets is associated with a respective date and time period and with object change records for objects having a timestamp falling within the respective date and time period. Each of the object change records is associated with a unique object identifier and the timestamp for a corresponding one of the objects. The timestamp specifies a date and a time corresponding to a latest one of a creation time or a most recent update time for the corresponding one of the objects.

Abstract: A technique for implementing policy-aware backup and restore capability in a tiered storage system. If a data set's contents are backed up from the tiered storage system to a backup storage system, metadata for the data set may also be backed up. Prior to the data set being restored from the backup storage system to the tiered storage system, the backed up metadata is restored and processed to determine a tier among the tiered storage pools to which the data set will be restored.

Abstract: A method and system for conducting an integrity check of system and user metadata when the metadata is mounted. A filesystem reviewer is embedded within software of a server node. A mutual exclusion lock is obtained on the selected metadata. An automated verification of the locked metadata is conducted while the filesystem is mounted. In addition, an automated salvage of the locked metadata may be conducted while the filesystem is mounted. The verification and/or salvage of the locked metadata can be applied to system, user, and/or a portion of the user metadata.

Abstract: A method and system for allocating blocks of disk in persistent storage to requesting threads. A primary data structure is provided for organizing and categorizing blocks of disk space. In addition, a secondary data structure is provided for maintaining a list of all active file system processes and blocks of disk space used by those processes. Blocks of disk space are assigned to pages. At such time as a thread may request allocation of disk space, both data structures are reviewed to determine if the requested disk space is available and to limit access of available disk space to a single page of memory to a single thread at any one time.

Abstract: A method and system for allocating blocks of disk in persistent storage to requesting threads. A primary data structure is provided for organizing and categorizing blocks of disk space. In addition, a secondary data structure is provided for maintaining a list of all active file system processes and blocks of disk space used by those processes. Blocks of disk space are assigned to pages. At such time as a thread may request allocation of disk space, both data structures are reviewed to determine if the requested disk space is available and to limit access of available disk space to a single page of memory to a single thread at any one time.

Abstract: There is provided, in a computer processing system, an apparatus for managing object data. The apparatus includes a changed objects manager for creating and managing a changed objects list that at least identifies the objects that have changed based on time of change. The changed objects list is associated with a plurality of time buckets. Each of the plurality of time buckets is associated with a respective date and time period and with object change records for objects having a timestamp falling within the respective date and time period. Each of the object change records is associated with a unique object identifier and the timestamp for a corresponding one of the objects. The timestamp specifies a date and a time corresponding to a latest one of a creation time or a most recent update time for the corresponding one of the objects.

Abstract: A method and system for allocating blocks of disk in persistent storage to requesting threads. A primary data structure is provided for organizing and categorizing blocks of disk space. In addition, a secondary data structure is provided for maintaining a list of all active file system processes and blocks of disk space used by those processes. Blocks of disk space are assigned to pages. At such time as a thread may request allocation of disk space, both data structures are reviewed to determine if the requested disk space is available and to limit access of available disk space to a single page of memory to a single thread at any one time.

Abstract: A method and system for conducting an integrity check of system and user metadata when the metadata is mounted. A filesystem reviewer (48, 74, 84) is embedded within software of a server node. A mutual exclusion lock is obtained on the selected metadata (54, 82, 116, 202, 242, 302). An automated verification of the locked metadata is conducted (58, 86, 120, 156, 206, 246, 306) while the filesystem is mounted. In addition, an automated salvage of the locked metadata may be conducted (62, 90, 124, 158, 210, 250, 310) while the filesystem is mounted. The verification and/or salvage of the locked metadata can be applied to system, user, and/or a portion of the user metadata.

Abstract: A system and method for managing logical versions of a filesystem made through a near-instantaneous copy process is provided. Each logical version of the filesystem, including the primary version, is assigned a unique epoch number or other identifying value, and each filesystem object is assigned two epoch numbers that define the space of logical versions for which the object exists. A list of all valid epoch numbers are maintained in a version table. The near-instantaneous creation of a logical version of the filesystem requires inserting a unique epoch number entry in the version table (106) and the next epoch number to the new logical version. An original state of the system is preserved through the use of a copy-on-write procedure for filesystem objects that are reference by that logical filesystem version (120). Accordingly, filesystem versions are maintained and original states of previous states of the logical filesystem versions are preserved.

Abstract: Various copy-on-write implementations for a computing environment are presented. One copy-on-write implementation includes employing a read mapping table to perform a first virtual block to physical block mapping for use in reading a block of data of a file to be copy-on-written from physical storage for modification; and employing a different, write mapping table to perform a second virtual block to physical block mapping for use in writing a modified block of the file data to physical storage, wherein copy-on-write of the block of data is achieved using a single write operation. In another implementation, a distributed copy-on-write of a file for a client server environment is presented. This distributed copy-on-write includes performing, by a first client, copy-on-write of at least one block of data of the file to be copy-on-written, and performing, by a second client, copy-on-write of at least one other block of data of the file, wherein multiple clients perform the copy-on-write of the file.

Abstract: A method and system for conducting an integrity check of system and user metadata when the metadata is mounted. A filesystem reviewer (48, 74, 84) is embedded within software of a server node. A mutual exclusion lock is obtained on the selected metadata (54, 82, 116, 202, 242, 302). An automated verification of the locked metadata is conducted (58, 86, 120, 156, 206, 246, 306) while the filesystem is mounted. In addition, an automated salvage of the locked metadata may be conducted (62, 90, 124, 158, 210, 250, 310) while the filesystem is mounted. The verification and/or salvage of the locked metadata can be applied to system, user, and/or a portion of the user metadata.

Abstract: A system and method for managing logical versions of a filesystem made through a near-instantaneous copy process is provided. Each logical version of the filesystem, including the primary version, is assigned a unique epoch number or other identifying value, and each filesystem object is assigned two epoch numbers that define the space of logical versions for which the object exists. A list of all valid epoch numbers are maintained in a version table. The near-instantaneous creation of a logical version of the filesystem requires inserting a unique epoch number entry in the version table (106) and the next epoch number to the new logical version. An original state of the system is preserved through the use of a copy-on-write procedure for filesystem objects that are reference by that logical filesystem version (120). Accordingly, filesystem versions are maintained and original states of previous states of the logical filesystem versions are preserved.

Abstract: Various copy-on-write implementations for a computing environment are presented. One copy-on-write implementation includes employing a read mapping table to perform a first virtual block to physical block mapping for use in reading a block of data of a file to be copy-on-written from physical storage for modification; and employing a different, write mapping table to perform a second virtual block to physical block mapping for use in writing a modified block of the file data to physical storage, wherein copy-on-write of the block of data is achieved using a single write operation. In another implementation, a distributed copy-on-write of a file for a client server environment is presented. This distributed copy-on-write includes performing, by a first client, copy-on-write of at least one block of data of the file to be copy-on-written, and performing, by a second client, copy-on-write of at least one other block of data of the file, wherein multiple clients perform the copy-on-write of the file.

Abstract: Laminated slabs superficially bonded together are prepared by autoclaving a vertically compressed stack including a plurality of the sheets when initially set but not finally cured and having a polyethylene or like plastic film-like layer sandwiched between each pair of the sheet surfaces to be bonded together. A layer of material other than asbestos-cement may be sandwiched between the asbestos-cement sheets, for example, metal foil, to make the slab moisture-impervious or an array of filaments or wire-mesh material as reinforcement may be used.