Abstract: A computer-implemented method comprises transitioning from a unidirectional asynchronous replication to initiating bi-directional synchronous replication between one or more storage objects of a first consistency group (CG1) of a primary storage site and one or more storage objects of a second consistency group (CG2) of a secondary storage site, converting the one or more storage objects of the CG2 from data protection read only access to read write access, and performing a reverse synchronization process between the one or more storage objects of the CG2 and the one or more storage objects of the CG1 including instantiating a reverse splitter on each volume of CG2, establishing reverse sync replication sessions for each storage object of the CG2, and allowing input output (IO) access to the one or more storage objects of the CG2.

Abstract: Multi-site distributed storage systems and computer-implemented methods are described for improving a resumption time of input/output (I/O) operations during a common snapshot process for storage objects. A computer-implemented method comprises performing a baseline transfer from at least one storage object of a first storage node to at least one replicated storage object of a second storage node, starting the common snapshot process including stop processing of I/O operations, performing a snapshot create operation on the primary storage site for the at least one storage object of the first storage node, resuming processing of I/O operations, and assigning a new universal unique identifier (UUID) to the at least one storage object of the second storage node after resuming processing of I/O operations with the new UUID to identify when file system contents are different than the baseline transfer.

Abstract: Multi-site distributed storage systems and computer-implemented methods are described for improving a resumption time of input/output (I/O) operations during a common snapshot process for storage objects. A computer-implemented method comprises performing a baseline transfer from at least one storage object of a first storage node to at least one replicated storage object of a second storage node, starting the common snapshot process including stop processing of I/O operations, performing a snapshot create operation on the primary storage site for the at least one storage object of the first storage node, resuming processing of I/O operations, and assigning a new universal unique identifier (UUID) to the at least one storage object of the second storage node after resuming processing of I/O operations with the new UUID to identify when file system contents are different than the baseline transfer.

Abstract: Multi-site distributed storage systems and computer-implemented methods are described for improving a resumption time of input/output (I/O) operations during a common snapshot process for storage objects. A computer-implemented method comprises performing a baseline transfer from at least one storage object of a first storage node to at least one replicated storage object of a second storage node, starting the common snapshot process including stop processing of I/O operations, performing a snapshot create operation on the primary storage site for the at least one storage object of the first storage node, resuming processing of I/O operations, and assigning a new universal unique identifier (UUID) to the at least one storage object of the second storage node after resuming processing of I/O operations with the new UUID to identify when file system contents are different than the baseline transfer.

Abstract: Systems and methods are described for efficiently performing various operations at the granularity of a consistency group (CG) within a cross-site storage solution. An example of one of the various operations includes an independent and parallel resynchronization approach that independently brings individual volumes of a CG to a steady state of in-synchronization (InSync), thereby contributing to scalability of CGs by supporting CGs having a large number of member volumes without requiring a change to the resynchronization process. Another example includes preserving dependent write-order consistency when a remote mirror copy goes out-of-synchronization (OOS) for any reason by driving all member volumes OOS responsive to any member volume becoming OOS. Yet another example includes independent creation of snapshots by member volumes to support efficient and on-demand creation by an application of a common snapshots of all or a subset of peered member volumes of a CG with which the application is associated.

Abstract: Systems and methods are described for a non-disruptive planned failover from a primary copy of data at a primary storage system to a mirror copy of the data at a cross-site secondary storage system. According to an example, a planned failover feature of a multi-site distributed storage system provides an order of operations such that a primary copy of a first data center continues to serve I/O operations until a mirror copy of a second data center is ready. This planned failover feature improves functionality and efficiency of the distributed storage system by providing non-disruptiveness during planned failover—even if various failures occur. The planned failover feature also includes a persistent fence to avoid serving I/O operations during a timing window when both primary data storage and secondary data storage are attempting to have a master role to serve I/O operations and this avoids a split-brain situation.

Abstract: Systems and methods are described for efficiently performing various operations at the granularity of a consistency group (CG) within a cross-site storage solution. An example of one of the various operations includes an independent and parallel resynchronization approach that independently brings individual volumes of a CG to a steady state of in-synchronization (InSync), thereby contributing to scalability of CGs by supporting CGs having a large number of member volumes without requiring a change to the resynchronization process. Another example includes preserving dependent write-order consistency when a remote mirror copy goes out-of-synchronization (OOS) for any reason by driving all member volumes OOS responsive to any member volume becoming OOS. Yet another example includes independent creation of snapshots by member volumes to support efficient and on-demand creation by an application of a common snapshots of all or a subset of peered member volumes of a CG with which the application is associated.

Abstract: Systems and methods are described for a non-disruptive planned failover from a primary copy of data at a primary storage system to a mirror copy of the data at a cross-site secondary storage system. According to an example, a planned failover feature of a multi-site distributed storage system provides an order of operations such that a primary copy of a first data center continues to serve I/O operations until a mirror copy of a second data center is ready. This planned failover feature improves functionality and efficiency of the distributed storage system by providing non-disruptiveness during planned failover - even if various failures occur. The planned failover feature also includes a persistent fence to avoid serving I/O operations during a timing window when both primary data storage and secondary data storage are attempting to have a master role to serve I/O operations and this avoids a split-brain situation.

Abstract: Systems and methods are described for a non-disruptive planned failover from a primary copy of data at a primary storage system to a mirror copy of the data at a cross-site secondary storage system. According to an example, a planned failover feature of a multi-site distributed storage system provides an order of operations such that a primary copy of a first data center continues to serve I/O operations until a mirror copy of a second data center is ready. This planned failover feature improves functionality and efficiency of the distributed storage system by providing non-disruptiveness during planned failover—even if various failures occur. The planned failover feature also includes a persistent fence to avoid serving I/O operations during a timing window when both primary data storage and secondary data storage are attempting to have a master role to serve I/O operations and this avoids a split-brain situation.

Abstract: Systems and methods are described for a non-disruptive planned failover from a primary copy of data at a primary storage system to a mirror copy of the data at a cross-site secondary storage system. According to an example, a planned failover feature of a multi-site distributed storage system provides an order of operations such that a primary copy of a first data center continues to serve I/O operations until a mirror copy of a second data center is ready. This planned failover feature improves functionality and efficiency of the distributed storage system by providing non-disruptiveness during planned failover—even if various failures occur. The planned failover feature also includes a persistent fence to avoid serving I/O operations during a timing window when both primary data storage and secondary data storage are attempting to have a master role to serve I/O operations and this avoids a split-brain situation.

Abstract: Systems and methods are described for efficiently performing various operations at the granularity of a consistency group (CG) within a cross-site storage solution. An example of one of the various operations includes an independent and parallel resynchronization approach that independently brings individual volumes of a CG to a steady state of in-synchronization (InSync), thereby contributing to scalability of CGs by supporting CGs having a large number of member volumes without requiring a change to the resynchronization process. Another example includes preserving dependent write-order consistency when a remote mirror copy goes out-of-synchronization (OOS) for any reason by driving all member volumes OOS responsive to any member volume becoming OOS. Yet another example includes independent creation of snapshots by member volumes to support efficient and on-demand creation by an application of a common snapshots of all or a subset of peered member volumes of a CG with which the application is associated.

Abstract: An application programming interface (API) is used to migrate, from a specified source LUN to a specified target LUN, at least one specified sub-LUN data chunk, the API functioning as an interface between a storage controller and an owning application.

Abstract: An application programming interface (API), functioning as an interface between a storage controller and an owning application, is used to migrate, from a specified source LUN to a specified target LUN, at least one specified sub-LUN data chunk, the at least one specified sub-LUN data chunk having a predefined chunk size fixed by the storage controller. A specified total migration size is incrementally reduced by each completed migration of the at least one specified sub-LUN data chunk until the total migration size is zero and the migration is completed.

Abstract: A source code-based specification is implemented for use as an interface between a storage controller and an owning application to migrate a specified size of data from physical storage behind the LUN to a new physical location.