Abstract: Techniques are provided for processing an Input/Output (I/O) request. At least one data block is allocated for use in completing the I/O request. A current operations record is stored for the I/O request. It is determined whether the I/O request has been completed within a specified period of time. In response to determining that the I/O request has not been completed within the specified period of time, the allocated at least one data block is fenced.

Abstract: Techniques are provided for processing an Input/Output (I/O) request in which an identification message is received from a client computer. It is determined whether the client computer is a rogue client based on whether a current operations record exists for the client computer.

Abstract: Techniques are provided for processing an Input/Output (I/O) request. At least one data block is allocated for use in completing the I/O request. A current operations record is stored for the I/O request. It is determined whether the I/O request has been completed within a specified period of time. In response to determining that the I/O request has not been completed within the specified period of time, the allocated at least one data block is fenced.

Abstract: Provided are techniques for determining whether content of an object has changed. Under control of a backup system, opaque object attributes and a data identifier are received, wherein the data identifier is generated based on one or more relevant object attributes of the opaque object attributes that indicate whether at least one of the content of the object and one or more of the relevant object attributes has changed. The received data identifier is compared with a previously stored data identifier. In response to determining that the received data identifier and the previously stored data identifier do not match, it is determined that the content of the object has changed.

Abstract: File system objects of unknown type are backed up and restored. A list of file system objects is received from a file system. The file system objects are to be backed up. For each file system object that has a file type that is unknown, the following is performed. First, the file system is queried to obtain information regarding the file system object that is sufficient for the file system to later recreate the file system object if necessary. Second, the file system object and the information regarding the file system object are stored. Examples of file system object types of the file system that may be unknown to an application running on a Microsoft Windows® operating system include symbolic links, named pipes, and special device files.

Abstract: A variable known as an allocation coefficient is assigned to a file for use in calculating the maximum number of blocks to be allocated in response to a block allocation request. The allocation coefficient may be adjusted in response to each individual request to reflect the current state of block consumption on an object. Similarly, the allocation coefficient may be adjusted in response to a synchronization transaction based upon the usage of requested blocks for past write operations. In response to either situation, the allocation coefficient is adaptable to reflect an increase or a decrease in block consumption and to more accurately allocate blocks for a write operation in response to characteristics of prior operations.

Abstract: A method and system for supporting a concurrent recordation of a change in a data file by a server while allowing an application to continue writing changes to a data file. In response to a change in a data file, a near-instantaneous version of the file is created. Metadata reflecting the change to the data file are synchronized with a version of the file in cache and recorded in persistent storage. During the process of recording metadata changes to the file, subsequent changes to the data file may continue, and metadata reflecting the changes may be recorded in a subsequent near-instantaneous version of the file which may also be synchronized with a version of the metadata in persistent storage.

Abstract: Techniques are provided for processing an Input/Output (I/O) request. At least one data block is allocated for use in completing the I/O request. A current operations record is stored for the I/O request. It is determined whether the I/0 request has been completed within a specified period of time. In response to determining that the I/O request has not been completed within the specified period of time, the allocated at least one data block is fenced. Also provided are techniques for processing an Input/Output (I/O) request in which an identification message is received from a client computer. It is determined whether the client computer is a rogue client based on whether a current operations record exists for the client computer.

Abstract: A method and system for managing availability of a dependent thread to service a nested request is provided. A plurality of reply threads are maintained in a single thread pool. In addition, a counter is provided to track availability of a reply thread from the thread pool. A service thread that requires at least one reply thread to complete execution of a request must check the counter to determine availability of the reply thread prior to execution of the request. The process of determining availability of a reply thread prior to execution of a service thread request avoids initiating execution of a request that cannot be completed in a timely manner, or at all.

Abstract: Facilitating error handling of computing environments, including those environments having file systems. Responsive to an entity of the computing environment, such as a client of a file system, obtaining at least an indication of an error, a portion of functionality of the entity is automatically frozen. The obtaining is, for instance, responsive to an event of another entity of the computing environment, such as a server of the file system. Eventually, the frozen functionality is thawed allowing the functionality to proceed.