Abstract: There is disclosed a technique for managing data inconsistencies in file systems. For example, in one embodiment, the technique comprises detecting a data inconsistency relating to a file system block in a file system. The technique also comprises determining whether the file system block includes a mapping pointer associated with a first type of pattern. The technique further comprises performing recovery in connection with the file system block. The recovery including deciding whether to associate a mapping pointer of the file system block with one of a second type of pattern or a data loss state based on the said determination of whether the file system block includes a mapping pointer associated with a first type of pattern.

Abstract: There is disclosed techniques for managing data storage. In one embodiment, the techniques comprise recording index information in a block-based segment of a file system. The index information relates to an extent list in a virtual block map (VBM) pointing to the block-based segment. The techniques also comprise detecting an error in connection with the VBM. The techniques also comprise rebuilding the VBM based on the index information in response to detecting the error.

Abstract: Processing for a file system may include determining an inconsistency between a data log and inodes (index nodes) of the file system. Responsive to determining the inconsistency, recovery processing may be performed including first processing of the data log, second processing of the inodes of the file system, and third processing of the data log after said second processing. First processing may, for each entry of the data log that records a create snapshot operation to create a snapshot of a file having an associated inode of the file system that is a dirty snapshot inode, marking the associated inode as “snap validated”. Second processing may include freeing each dirty snapshot inode not marked as “snap validated”. Third processing may include freeing any entry of the data log where the entry references dirty snapshot inode freed by the second processing.

Abstract: There is disclosed techniques for managing data storage. In one embodiment, the techniques comprise determining whether a part of a file system block is associated with deduplication. The techniques also comprise updating a deduplication record of the file system block, based on the said determination, to indicate a deduplication status in connection with the part such that the updated deduplication record describes for multiple occurrences of one or more parts of the file system block whether the respective one or more parts are associated with deduplication.

Abstract: There is disclosed techniques for managing lost writes in file systems. In one embodiment, the techniques detect a virtual block map (VBM) lost write in a deduplication-enabled file system. The VBM lost write resulting in a first VBM being re-allocated such that a first and a second multi-block segment point to the first VBM but the first VBM points to the first segment and not the second segment. The techniques also rebuild a second VBM that points to the second segment. The techniques also determine if a mapping pointer (MP) is a deduplication MP or a non-deduplication MP. The techniques also determine whether to connect the MP to the first VBM or the second VBM.

Abstract: There is disclosed techniques for managing data storage. In one embodiment, the techniques comprise recording index information in a block-based segment of a file system. The index information relates to an extent list in a virtual block map (VBM) pointing to the block-based segment. The techniques also comprise detecting an error in connection with the VBM. The techniques also comprise rebuilding the VBM based on the index information in response to detecting the error.

Abstract: There is disclosed techniques for managing data storage. In one embodiment, the techniques comprises detecting a corrupted state in connection with a leaf indirect block (IB). The IB comprises a deduplication mapping pointer (MP) pointing to an extent in a virtual block map (VBM). The techniques further comprising determining, in response to the detection, that an VBM address associated with the MP is a valid VBM address and that a sum of weights describing a total number of MPs pointing to the extent in the VBM is missing a weight after traversing an IB tree comprising multiple IBs including the M. The techniques further comprising connecting the MP to the extent in the VBM based on the determination.

Abstract: There is disclosed techniques for managing data storage. In one embodiment, the techniques comprise determining whether a part of a file system block is associated with deduplication. The techniques also comprise updating a deduplication record of the file system block, based on the said determination, to indicate a deduplication status in connection with the part such that the updated deduplication record describes for multiple occurrences of one or more parts of the file system block whether the respective one or more parts are associated with deduplication.

Abstract: A method, computer program product, and computer system for receiving, at a computing device, an I/O request directed to a compressed data portion of a storage system. It may be determined whether the I/O request includes one of a first portion of information and a second portion of information. An address of the compressed data portion may be obtained via downward mapping if the I/O request includes the first portion of information. The address of the compressed data portion may be obtained via upward mapping if the I/O request includes the second portion of information. The I/O request may be executed at the compressed data portion.

Abstract: A technique for repairing damage to a file system stores compression headers in association with respective extents of in-line compressed data. A repair utility reads contents from the compression headers and applies the contents to repair damaged metadata structures that the file system uses to access the associated extents. In this fashion, the repair utility restores access to compressed data, which would otherwise be lost.

Abstract: A data inconsistency is detected in a file system data block of a file system. The file system includes a set of files, each file includes a set of file system data blocks. Information regarding a file including the data inconsistency is provided to a client of the file system. Based on the information, the client is enabled to determine an action for recovering from the data inconsistency.

Abstract: A method, computer program product, and computer system for receiving, at a computing device, an I/O request directed to a compressed data portion of a file system. A field associated with the compressed data portion may be determined to be invalid. An error may be generated in response to determining that the field associated with the compressed data portion is invalid. The file system may be maintained in an online status while the compressed data portion is invalid.

Abstract: A method is used in managing data inconsistencies in file systems. A data inconsistency is detected in a file system data block of a file system. The file system includes a set of file system data blocks. Information regarding the data inconsistency is provided to a client of the file system. Based on the information, the client is enabled to determine an action for recovering from the data inconsistency.

Abstract: A method is used in managing data inconsistencies in files of file systems. A data inconsistency is detected in a file system data block of a file system. The file system includes a set of files, each file includes a set of file system data blocks. Information regarding a file including the data inconsistency is provided to a client of the file system. Based on the information, the client is enabled to determine an action for recovering from the data inconsistency.

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: A technique manages data within a data storage apparatus having a cache of volatile memory and non-volatile storage. The technique involves receiving a set of write commands to write data to the non-volatile storage. The technique further involves acknowledging, in a write-back caching manner, completion of the set of write commands after the data reaches the cache of volatile memory and prior to the data reaching the non-volatile storage. The data includes host data as well as critical metadata. The technique further involves saving, after acknowledging completion of the set of write commands, the data from the cache of volatile memory to the non-volatile storage, the critical metadata being saved from the cache of volatile memory to the non-volatile storage at a quicker rate than that of the host data (i.e., accelerated synchronization of the critical metadata).

Abstract: A technique of managing thin pool logical unit (TLU) recovery is performed in a data storage array that forms TLUs from a slice storage pool of logical unit (LUN) slices. The technique involves allocating a set of LUN slices of the slice storage pool to support TLU recovery. The technique further involves, after the set of LUN slices has been allocated, taking offline a TLU which currently requires TLU recovery. The technique further involves, while the TLU is offline, performing a TLU recovery procedure to recover the TLU. The TLU recovery procedure utilizes the set of LUN slices that was allocated to support TLU recovery.