Abstract: A recovery orchestration pipeline has stages configured to control efficient failover and recovery of applications in a multi-site disaster recovery (DR) environment. The applications run on user virtual machines (UVMs) at a primary site of the DR environment and connect to block storage devices (BSDs) that export virtual disks over a storage protocol to consume data including a recovery plan for disaster recovery. The recovery plan includes a recovery configuration whose generation is triggered by a user via a graphical user interface (GUI) and specifies resource requirements needed to recover the applications at a secondary site in the event of a disaster. The orchestration pipeline is initiated via single click of the GUI and completion of the stages of the pipeline is displayed as progress via the GUI to allow recovery of the applications without user intervention.

Abstract: Last resort access to backups is disclosed. An encrypted backup associated with a first system or vault is stored in the backup associated with another system. If a key needed to decrypt a backup in the first vault is unavailable, an encrypted copy of a backup in the second vault may be used for the recovery operation. Incremental backups from the first and/or second vault, which may be difference incremental backups and may be unencrypted, may be used in the recovery operation.

Abstract: Snapshot-based disaster recovery (DR) orchestration systems and methods for virtual machine (VM) failover and failback do not require that VMs or their corresponding datastores be actively operating at the DR site before a DR orchestration job is initiated, i.e., before failover. An illustrative data storage management system deploys proprietary components at source data center(s) and at DR site(s). The proprietary components (e.g., storage manager, data agents, media agents, backup nodes, etc.) interoperate with each other and with the source and DR components to ensure that VMs will successfully failover and/or failback. DR orchestration jobs are suitable for testing VM failover scenarios (“clone testing”), for conducting planned VM failovers, and for unplanned VM failovers. DR orchestration jobs also handle failback and integration of DR-generated data into the failback site, including restoring VMs that never failed over to fully re-populate the source/failback site.

Abstract: A data restore system is provided. The data restore system includes a backup data storage configured to store data for a client and a data restore module configured to receive a restore trigger from the client and to initiate restore operation for selected data from the backup data storage in response to the received trigger. The data restore module is further configured to receive information regarding the selected data to be restored and access a metadata store to receive metadata information for the selected data and provide the metadata information and the downloaded data blocks to a controller to facilitate sorting of the downloaded data blocks based on the files they belong to and store the downloaded restored data to a target data storage. The data restore module is further configured to interact with the checkpointing module to track the progress of restore operation in persistent storage and to minimize rework when restore operation is restarted from interrupt.

Abstract: Described herein are techniques for automating media agent state management. For example, if a media agent is running poorly, then the media agent can be disabled and an alternate media agent can perform secondary copy job operations in place of the poorly running media agent. To determine whether a media agent is running poorly, a storage manager can determine whether the media agent has an anomalous number of failed jobs, pending jobs, and/or long running jobs and/or can determine whether the amount of resources used by the media agent is high or is increasing constantly, at a constant rate, or at a near constant rate.

Abstract: In various embodiments, a process for providing a cloud service provider request retry framework includes obtaining a request retry indicator that is associated with a cloud service provider, wherein the request retry indicator indicates a retry criterion that is based on a number of allowable discovery requests within a period of time. The process includes providing a discovery request to the cloud service provider; receiving an error response based on the discovery request, wherein the error response indicates the discovery request is unsuccessful based at least on the discovery request not satisfying the retry criterion; and determining a wait time based at least on the error response and the request retry indicator. The process includes retrying the discovery request according to the wait time.

Abstract: A system for extending the utility of blockchain environments when such environments become too large or complex, is disclosed. The system systematically creates a second generation, or child blockchain that can retain machine-readable links to the parent blockchain which, in turn, can be archived and referenced, when necessary, for historical reference. Accordingly, the system serves to reduce the size of the working blockchain thereby making it easier to store the blockchain, and further serves to increase the speed of queries to interrogate the current state of the blockchain. By reducing the size of the working blockchain, the present invention seeks to extend the utility of large blockchains by segregating and archiving historical or older transactions recorded in the blockchain. The system and process further include methodologies to create links between the current blockchain and the archived sections of the blockchain to ensure the integrity of the full historical ledger.

Abstract: Multi-site distributed storage systems and computer-implemented methods are described for improving a resumption time of input/output (I/O) operations during an automatic unplanned failover (AUFO). A computer-implemented method includes determining, with a second storage cluster, whether heartbeat information from one or more storage objects of a CG of a first set of CGs is received during a time period, determining an out of sync state for a data replication relationship between the CG of the first set of CGs and a mirrored CG of a second set of CGs when the heartbeat information is not received during the time period and sending a single bulk role change call with a cluster identifier from the second cluster to an external mediator to provide a role change from follower to leader in the second set of CGs.

Abstract: A storage system switching between mediation models within a storage system, where the switching between mediation models includes: determining, among one or more of the plurality of storage systems, a change in availability of a mediator service, wherein one or more of the plurality of storage systems are configured to request mediation from the mediator service in response to a fault; and communicating, among the plurality of storage systems and responsive to determining the change in availability of the mediator service, a fault response model to be used as an alternate to the mediator service among one or more of the plurality of storage systems.

Abstract: In a storage system that acquires data from a storage system via a network, in the storage system, a snapshot 108 with respect to a predetermined volume is managed, the storage system includes a CPU, and the CPU is configured to receive an acquisition instruction of data of a first snapshot of the predetermined volume and acquire at least a part of data of a difference between the first snapshot and a second snapshot from the storage system when data of the second snapshot of the predetermined volume is acquired.

Abstract: Systems and methods are described for use of reserved storage capacity at a cloud provider network extension, sometimes referred to as a provider substrate extension (“PSE”) or “outpost”, as a data cache, thereby improving performance of the PSE. The reserved storage capacity may be reserved for a primary purpose, such as data replication in the event of failure of an in-use portion of the PSE's storage capacity. During non-failover operation, the reserved storage capacity may be otherwise unused. Embodiments of the present disclosure enable the reserved storage capacity, when not used for its primary purpose, to be used as a data cache to store information potentially used at the PSE.

Abstract: Embodiments help timely remediation of issues in a data protection system by automatically evaluating scripts configured to address the issues. The system has a bounded list of possible attributes that are deemed important by system administrators. Each attribute is assigned a System Impact Score (SIS) along a defined scale. A self-healing processing component monitors the state of each attribute over time. The scripts are evaluated through repeated execution and use of the attribute monitoring to determine which attributes are affected by a script. Weights are assigned to each attribute affected by a script to aid in the selection of scripts most likely to remediate an actionable issue. Regularly performing script evaluation and attribute weighting allows for updating of scripts with an accurate list of attributes to overcome problems associated with manual updates.

Abstract: Communications are exchanged with a copy service of a host to identify writers associated with the copy service. The identification includes a type of a writer as being a system or application writer. Writers identified as system writers are added to a list of writers that should participate in a backup operation. For writers identified as application writers, components of an application writer are iterated through to determine whether a component of the application writer has a name or logical path that includes a name of a system service. When any component has the name or logical path that includes the name of the system service, the application writer is promoted to be of type system writer by adding the application writer to the list of writers that should participate in the backup operation. Components of each writer listed in the list of writers are backed up.

Abstract: An example method of providing a common volume (cVol) datastore for virtual machines (VMs) managed by a hypervisor in a virtualized computing system is described. The method includes: mounting, by the hypervisor, a network file system share of a common volume (cVol), the cVol stored in shared storage of the virtualized computing system, the network file system share storing metadata for the VMs; creating a file system for the cVol datastore backed by the network file system share; routing file operations targeting the metadata to the file system for the cVol datastore; and routing file operations targeting virtual disks of the VMs to an object storage pool of the cVol based on descriptors in the metadata that point to objects backing the virtual disks.

Abstract: An adaptive interface high availability storage device. In some embodiments, the adaptive interface high availability storage device includes: a rear storage interface connector; a rear multiplexer, connected to the rear storage interface connector; an adaptable circuit connected to the rear multiplexer; a front multiplexer, connected to the adaptable circuit; and a front storage interface connector, connected to the front multiplexer. The adaptive interface high availability storage device may be configured to operate in a single-port state or in a dual-port state. The adaptive interface high availability storage device may be configured: in the single-port state, to present a single-port host side storage interface according to a first storage protocol at the rear storage interface connector, and in the dual-port state, to present a dual-port host side storage interface according to the first storage protocol at the rear storage interface connector.

Abstract: Targetless snapshots of a storage object are characterized in terms of likelihood of access using time-series analysis. Metadata of replication data structures of individual targetless snapshots is maintained in either uncompressed or compressed form based on the characterization of the targetless snapshot. Metadata is compressed at the page level, with same-pages of all replication data structures of cold snapshots of a storage object being compressed together. Compressed pages of targetless snapshot metadata are maintained of storage devices selected based on storage device performance and the time-series characterization of the targetless snapshot.

Abstract: A folder scan system configured to identify modified folders in a storage module including a plurality of folders during an incremental backup scan is presented. The folder scan system is configured to identify modified folders using a learning-based technique. A related method is also presented.

Abstract: A data storage device includes a memory device and a controller coupled to the memory device. The controller is configured to compare a first copy of a boot partition to a second copy of the boot partition. The first copy of the boot partition and the second copy of the boot partition each comprises a same number of a plurality of boot chunks. The boot partition corresponds to data of a boot operation of a host device. The controller is further configured to mark one or more of the compared boot chunks that equals or exceeds a similarity threshold and update a reliability index based on the marking. Based on the marking and the reliability index, the controller may increase or decrease an amount of error correction needed for the boot data.

Abstract: A object data backup and restore method and system include receiving a request to restore a target object to a first point-in-time version; identifying a first snapshot of the cluster corresponding to the first point-in-time version; generating a second snapshot of the cluster upon receiving the request to restore the target object; determining data changes associated with the target object based on the first snapshot and second snapshot; scanning all objects associated with the cluster to determine one or more additional objects that are affected by restoring the target object due to object dependencies defined by a cluster configuration; generating a relationship graph for the one or more additional objects and the target object; and restoring the target object based on the data changes, the first snapshot and the relationship graph.

Abstract: A method and system is disclosed for backing up and maintaining electronic medical records for periods of temporary loss of connectivity between a healthcare facility and an eMAR/eTAR provider storing and maintaining medication administration records and treatment administration records for a healthcare facility.

Abstract: A memory tier is established in a cluster system having a deduplicated file system. The memory tier includes memory pages configured as huge pages, where writes to the huge pages are exported in a device file that is outside of a user process namespace within which processes of the deduplicated file system run. At least a portion of metadata generated by the deduplicated file system is written to the memory tier. The portion of metadata includes an index of fingerprints corresponding to data segments stored by the deduplicated file system to a storage pool. A determination is made that an instance of the deduplicated file system has failed. A new instance of the deduplicated file system is started to recover file system services by loading the index of fingerprints from the device file.

Abstract: A specification of a data protection intent is received. Configurations for a plurality of different data management services are automatically determined in an attempt to achieve the specified data protection intent. The determined configurations in the plurality of different data management services are automatically implemented.

Abstract: In some examples, a method of performing a backup of a group of relational databases comprises identifying the group of relational databases; identifying I/O traffic flowing into or out of the group of relational databases; temporarily freezing the I/O traffic flowing into or out of the group of relational databases; identifying a set of batch backup operations to be performed during the temporary I/O freeze; identifying relational dependencies between at least some databases in the group of relational databases; based on the identified relational dependencies, identifying, among the set of batch backup operations, a first sub-set of backup operations eligible to be performed in parallel, and a second sub-set of backup operations not eligible to be performed in parallel; conducting the backup, wherein conducting the backup comprises performing the identified first sub-set of backup operations in parallel and performing the identified second sub-set of backup operations sequentially; and unfreezing the I/O tra

Abstract: Responsive to determining that a step in an interaction sequence has below a threshold similarity to any step in a set of log sequences, a first log entry is caused to be generated. The first log entry is emitted responsive to execution of the step in the interaction sequence by the software application. Responsive to determining that a starting key action lacks a corresponding ending key action, a second log entry is caused to be generated. The second log entry is emitted responsive to execution of code related to the corresponding ending key action by the software application. Responsive to determining, using a trained anomaly detection model, that a keyword related to an injected fault is not present in resulting fault log data, a third log entry is generated. The third log entry is emitted responsive to execution of code related to the keyword by the software application.

Abstract: When a user exploits virtualization software and navigates through or to a redirected client drive in a remote session then the file management application may refresh the directory/folder content very slowly, spending significantly more time than expected according to the amount of data, network speed and latency. Whilst this refreshing is being performed no actions with the file management application can be performed by the user. Accordingly to address this a system or method are provided that cache metainformation for files, folders, and subfolders, e.g. upon a network resource, in a driver which responds to a query directory and other related requests by filling a provided buffer with the cached data. Further, this driver may filter out some particular files from the results if a filtering option is selected to further reduce latency.

Abstract: Transitioning between replication sources for data replication operations, including: delaying a transition from using a first data repository as a source for data replication to using a second data repository as the source for data replication after detecting that one or more storage operations directed to the first data repository have not been replicated to the second data repository; and promoting the second data repository as the source for data replication such that storage operations received after completing the transition are directed to the second data repository.

Abstract: Each redundancy group is constituted by one active program (storage control software of the active program) and N standby programs (N is an integer of two or more). Each of the N standby programs is associated with a priority to be determined as a failover (FO) destination. In the same redundancy group, FO is performed from the active program to the standby program based on the priority. For the plurality of pieces of storage control software including the active programs and the standby programs that change to be active by FO in the plurality of redundancy groups arranged in the same node, standby storage control software that can set each of the programs as a FO destination are arranged in different nodes.

Abstract: A BMC firmware security system includes a BMC coupled to a programmable circuit device and a first storage subsystem. In response to BMC initialization, the BMC uses a system identifier to verify that a license in the first storage subsystem authorizes the BMC to use BMC firmware in the BMC, uses branding identity information in the BMC to verify that the BMC is branded for the BMC firmware, determines that the programmable circuit device identifies the BMC firmware and, in response, the performs BMC initialization operations using the BMC firmware. A BIOS is coupled to the programmable circuit device and a second storage system. In response to BIOS initialization, the BIOS uses the branding identity information in the second storage subsystem to identify the BMC firmware, determines that the programmable circuit device identifies the BMC firmware and, in response, performs BIOS initialization operations.

Abstract: A fault tolerant computer system and method are disclosed. The system may include a plurality of CPU nodes, each including: a processor and a memory; at least two IO domains, wherein at least one of the IO domains is designated an active IO domain performing communication functions for the active CPU nodes; and a switching fabric connecting each CPU node to each IO domain. One CPU node is designated a standby CPU node and the remainder are designated as active CPU nodes. If a failure, a beginning of a failure, or a predicted failure occurs in an active node, the state and memory of the active CPU node are transferred to the standby CPU node which becomes the new active CPU node. If a failure occurs in an active IO domain, the communication functions performed by the failing active IO domain are transferred to the other IO domain.

Abstract: Techniques are provided to allow more sophisticated operations to be performed remotely by machines that are not fully functional. Operations that can be performed reliably by a machine that has experienced a hardware and/or software error are referred to herein as Remote Direct Memory Operations or “RDMOs”. Unlike RDMAs, which typically involve trivially simple operations such as the retrieval of a single value from the memory of a remote machine, RDMOs may be arbitrarily complex. The techniques described herein can help applications run without interruption when there are software faults or glitches on a remote system with which they interact.

Abstract: Techniques are provided to allow more sophisticated operations to be performed remotely by machines that are not fully functional. Operations that can be performed reliably by a machine that has experienced a hardware and/or software error are referred to herein as Remote Direct Memory Operations or “RDMOs”. Unlike RDMAs, which typically involve trivially simple operations such as the retrieval of a single value from the memory of a remote machine, RDMOs may be arbitrarily complex. The techniques described herein can help applications run without interruption when there are software faults or glitches on a remote system with which they interact.

Abstract: A technique involves: in response to receiving a request to write data to a storage device, acquiring metadata of a redundant array of independent disks (RAID) extent that is associated with the request to write data, the RAID extent being built based on disk slices comprised in a plurality of disks of the storage device; determining, based on the metadata, a disk slice of data write-enabled RAID extent to write the data; and copying an identification and a degradation number into a metadata page associated with a mapper for data recovery, the identification and degradation number being comprised in the metadata and associated with the data write-enabled RAID extent, the mapper being used to map a physical space and a virtual logical space, and the degradation number indicating the number of times that the disk slice comprised in the RAID extent changes from being normal to being degraded.

Abstract: A method for maintaining high-availability of file system instances is described. The method includes maintaining replica file system instances such as a first replica file system instance on a first computing node and a second replica file system instance on a second computing node. Further, a third computing node is instructed to create a sparse replica file system instance on the third computing node in response to detection of a failure condition associated with the second computing node. Moreover, a data update request is directed to the first replica file system instance and the sparse replica file system.

Abstract: Techniques are provided to allow more sophisticated operations to be performed remotely by machines that are not fully functional. Operations that can be performed reliably by a machine that has experienced a hardware and/or software error are referred to herein as Remote Direct Memory Operations or “RDMOs”. Unlike RDMAs, which typically involve trivially simple operations such as the retrieval of a single value from the memory of a remote machine, RDMOs may be arbitrarily complex. The techniques described herein can help applications run without interruption when there are software faults or glitches on a remote system with which they interact.

Abstract: The present disclosure describes example service takeover methods, storage devices, and service takeover apparatuses. In one example method, when a communication fault occurs between two storage devices in a storage system, the two storage devices respectively obtain running statuses of the two storage devices. A running status can reflect current usage of one or more system resources of a particular storage device. Then, a delay duration is determined according to the running statuses, where the delay duration is a duration for which the storage device waits before sending an arbitration request to a quorum server. The two storage devices respectively send, after the delay duration, arbitration requests to the quorum server to request to take over a service. The quorum server then can select a storage device in a relatively better running status to take over a host service.

Abstract: The invention introduces a non-transitory computer program product for handling a sudden power off recovery (SPOR) to include program code to: drive a flash access interface to read pages of a current block in sequence after a power restart subsequent to a sudden power off (SPO); mark the last correct page of the current block according to page read statuses for the current block; configure n1 pages after the next page of the last correct page of the current block as dummy pages; and drive the flash access interface to store data of the last correct page and its previous n2-1 pages of the current block in empty pages after the last dummy page of the current block, wherein any of n1 and n2 is a positive integer.

Abstract: Techniques are provided to allow more sophisticated operations to be performed remotely by machines that are not fully functional. Operations that can be performed reliably by a machine that has experienced a hardware and/or software error are referred to herein as Remote Direct Memory Operations or “RDMOs”. Unlike RDMAs, which typically involve trivially simple operations such as the retrieval of a single value from the memory of a remote machine, RDMOs may be arbitrarily complex. The techniques described herein can help applications run without interruption when there are software faults or glitches on a remote system with which they interact.

Abstract: Example implementations described herein are directed to backup and restore of a public cloud and data center for disaster recovery. In a backup process of the disaster recovery, the VM root device information (a public cloud) and storage system volume information (a data center) in a main site are transferred to the disaster recovery tool. In a restoration process, the DR Tool specifies the storage system volume for backup to attach the VM in a backup site with the above information.

Abstract: A data protection system configured to replicate data may generate rescue packages that allow the system to recover when communication between a splitter or source of the production data being replicated and an appliance that stores the replicated data is disrupted. The rescue package is stored on a datastore and is then retrieved by the data protection system or another splitter. After processing the rescue package, which may contain IOs that the data protection is unaware of due to the communication disruption, replication may resume normally.

Abstract: The technology disclosed herein pertains to a system and method for managing write failures in a disc drive. Implementations disclosed herein provide a method including monitoring write fault events per sector for a storage device, in response to a write fault event, updating a write fault repeat count table, wherein the repeat count table tracks a number of write fault repeat counts per sector, comparing a write fault repeat count for a sector to a predetermined threshold write fault repeat count, and in response to determining that the write fault repeat count for a sector is above the predetermined threshold write fault repeat count, performing a write-reassign operation.

Abstract: A failure in a main site is recovered by operating in the same operational environment as a sub site. A remote copy system includes: a first storage system providing a main site; and a second storage system providing a sub site. A storage controller stores data and an operation processed in the main site as a main site journal, sends the main site journal to the sub site for sequential processing, stores data and an operation processed in the sub site as a sub site journal after a failover to the sub site is performed, and cancels an unreflected operation that is not processed in the sub site after being stored in the main site journal prior to the failover in the main site and sequentially processes the sub site journal in the main site, when a failback to the main site is performed.

Abstract: Embodiments of the present disclosure provide a method, electronic device and computer program product for managing a backup system. The method comprises: determining, based on historical backup information of the backup system in a first time period, at least one temporal feature corresponding to the first time period, the historical backup information indicating a set of numbers of backup jobs executed by the backup system in the first time period; determining, based on the at least one temporal feature, a set of predicted numbers of backup jobs expected to be executed by the backup system in a second time period; and determining a health status of the backup system based on the set of predicted numbers and a set of actual numbers of backup jobs executed actually by the backup system in the second time period. In this way, the health status of the backup system can be determined in time.

Abstract: Failover methods and systems for a storage environment are provided. During a takeover operation to take over storage of a first storage system node by a second storage system node, the second storage system node copies information from a first storage location to a second storage location. The first storage location points to an active file system of the first storage system node, and the second storage location is assigned to the second storage system node for the takeover operation. The second storage system node quarantines storage space likely to be used by the first storage system node for a write operation, while the second storage system node attempts to take over the storage of the first storage system node. The second storage system node utilizes information stored at the second storage location during the takeover operation to give back control of the storage to the first storage system node.

Abstract: Systems and methods are provided for persisting a data structure. One method may comprise, at a front-end node in a computing system: generating a data structure operation record for a data structure operation directed to a data structure persisted in a non-volatile memory (NVM) in a back-end node of the computing system, appending the data structure operation record in an operation log, generating a transaction record for a transaction that includes a plurality of memory operations that collectively accomplishing the data structure operation, appending the transaction record in a transaction log, flushing the transaction log to the back-end node after flushing the operation log; and at the back-end node of the computing system: persisting received operation log and received transaction log in the NVM, and accomplishing the data structure operation by performing the plurality of the memory operation records with the data structure operation record as a commit signal.

Abstract: A system for extending the utility of blockchain environments when such environments become too large or complex, is disclosed. The system systematically creates a second generation, or child blockchain that can retain machine-readable links to the parent blockchain which, in turn, can be archived and referenced, when necessary, for historical reference. Accordingly, the system serves to reduce the size of the working blockchain thereby making it easier to store the blockchain, and further serves to increase the speed of queries to interrogate the current state of the blockchain. By reducing the size of the working blockchain, the present invention seeks to extend the utility of large blockchains by segregating and archiving historical or older transactions recorded in the blockchain. The system and process further includes methodologies to create links between the current blockchain and the archived sections of the blockchain to ensure the integrity of the full historical ledger.

Abstract: An illustrative embodiment disclosed herein is an apparatus including a processor having programmed instructions to map a plurality of objects to a region and map the region to a plurality of vdisks. The plurality of objects are stored in the plurality of vdisks. The processor has programmed instructions to, responsive to mapping the plurality of objects to the region, identify a policy associated with the region. The policy specifies a policy action in response to satisfying a predetermined condition. The processor has programmed instructions to, responsive to satisfying the predetermined condition, access the plurality of vdisks and perform the policy action on the plurality of objects.

Abstract: The present invention provides a control method of a server, wherein the control method includes the steps of: periodically controlling a first register and a second register of a first node to have a first value and a second value, respectively; periodically controlling a third register and a fourth register of a second node to have a third value and a fourth value, respectively; controlling the first register and the fourth register to synchronize with each other, wherein the first value is different from the fourth value; controlling the second register and the third register to synchronize with each other, wherein the second value is different from the third value; and periodically checking if the third register has the third value and the fourth register has the fourth value to determine if the first node fails to work.

Abstract: In a server (111), an updater (201) updates a file by an editing process that includes an adding process that adds a record to the end of a file. A collector (202) reads, in order of location in the file, a record included in the file, causes a collection device of a collection system to associate and collect the record and a position of the record in the file, and non-transitorily stores the position as an offset. An estimator (203) estimates whether header records located between the beginning of the file and the recorded offset are updated. When it is estimated that any of the header records are updated, a starter (204) causes the collector (202) to start reading the record from the beginning of the file. When it is estimated that none of the header records have been updated, the starter 204 causes the collector (202 to start reading the record from the recorded offset.

Abstract: A storage entity of the data storage system may be visible to the host over a first path and a second path. The first path may operate in accordance with a first protocol and the second path may operate in accordance with a second different protocol. The storage entity may have a first protocol level personality and identity when presented to the host over the first path and a second protocol level personality and identity when presented to the host over the second path. A first native identifier associated of the storage entity on the first path and a second native identifier of the storage entity on the second path may be used to determine that the same storage entity is visible over the first and second paths even though the storage entity may have different protocol level identifiers on the first and second paths that operate using different protocols.

Abstract: The rebuilding process comprises the steps of detecting a failure on a first server that stores a first data and processes input/output requests from an application, redirecting incoming input/output requests from the application to a second server storing a second data. The second data being mirrored from the first data. The process further comprises forming, by the first server, a data loss information that identifies the lost data units in the first data. The process further comprises rebuilding, by the first server, the lost data units in the first data, by using the data that is retrieved from the second data and based on the data loss information by the second server. The process further comprises syncing up data units, other than the lost data units in the first data, with corresponding data in the second data in the second server during the rebuilding process.