Abstract: A node mask of a global metadata structure entry representing an MD portion in GM may be updated when an entry of a local MD table representing the MD portion is removed in response to receiving an IO operation, without negatively impacting performance of the IO operation. An update process that is independent of the process executing the IO operation may update the node mask so that performance of the IO operation is not negatively affected. In response to the entry for the MD portion being removed from the local MD table, an entry may be added to a queue. The update process may include accessing the entries in the queue, and, for each entry, updating the node mask (e.g., clearing a bit representing the processing node) and removing the entry from the queue.

Abstract: Snapshots may be managed on a data storage system including logical storage unit including data portions. For a first logical storage unit, a first snapshot pointer structure may be provided including entries, each entry corresponding to a physical storage location at which data is stored for a data portion of the first logical storage unit at a particular point in time. A first virtual snapshot lookup table may be provided for a first portion of the first logical storage unit, the first virtual snapshot lookup table including a plurality of entries, each entry corresponding to a respective data portion of the first logical storage unit and including a reference to a respective entry of the first snapshot pointer structure. The virtual lookup table may correspond to multiple snapshots of the first logical storage unit that have a same value for each data portion of the at least first portion.

Abstract: Snapshots may be managed on a data storage system including logical storage unit including data portions. For a first logical storage unit, a first snapshot pointer structure may be provided including entries, each entry corresponding to a physical storage location at which data is stored for a data portion of the first logical storage unit at a particular point in time. A first virtual snapshot lookup table may be provided for a first portion of the first logical storage unit, the first virtual snapshot lookup table including a plurality of entries, each entry corresponding to a respective data portion of the first logical storage unit and including a reference to a respective entry of the first snapshot pointer structure. The virtual lookup table may correspond to multiple snapshots of the first logical storage unit that have a same value for each data portion of the at least first portion.

Abstract: A host system performs I/O processing using metadata for a storage system, where none or some of the metadata is stored on the host system. The host system may be coupled to the global memory of the storage system along a communication path that includes an internal switching fabric of the storage system and does not include a network located externally to the storage system. The host system may exchange communications over the communication path to access indirection layers on the storage system to determine a global memory address of metadata corresponding to an I/O operation. The host system may include a host metadata table of global memory addresses for metadata of logical locations logical devices. The host system may query the host metadata table for a global memory address of metadata corresponding to a logical location specified in an I/O operation.

Abstract: A node mask of a global metadata structure entry representing an MD portion in GM may be updated when an entry of a local MD table representing the MD portion is removed in response to receiving an IO operation, without negatively impacting performance of the IO operation. An update process that is independent of the process executing the IO operation may update the node mask so that performance of the IO operation is not negatively affected. In response to the entry for the MD portion being removed from the local MD table, an entry may be added to a queue. The update process may include accessing the entries in the queue, and, for each entry, updating the node mask (e.g., clearing a bit representing the processing node) and removing the entry from the queue.

Abstract: A host system performs I/O processing using metadata for a storage system, where none or some of the metadata is stored on the host system. The host system may be coupled to the global memory of the storage system along a communication path that includes an internal switching fabric of the storage system and does not include a network located externally to the storage system. The host system may exchange communications over the communication path to access indirection layers on the storage system to determine a global memory address of metadata corresponding to an I/O operation. The host system may include a host metadata table of global memory addresses for metadata of logical locations logical devices. The host system may query the host metadata table for a global memory address of metadata corresponding to a logical location specified in an I/O operation.