Abstract: A computing system can include a machine check counter (MCC) including a current value. The current value indicates a system reboot resetting hardware of the computing system. The machine check counter includes a model specific register including a counter indicating the current value, the current value to be incremented upon the system reboot.

Abstract: Facility for providing backup and restore of all data center components including physical machines, virtual machines, routers, networks, sub-networks, switches, firewall, directory lookup, DNS, DHCP and internet access. Virtual or physical machines are associated to data center components and a software defined network, storage, and compute infrastructure is provided.

Abstract: A primary storage controller is maintained in a copy relationship with a secondary storage controller, wherein the primary and secondary storage controllers are coupled to a host that is configurable to use the secondary storage controller instead of the primary storage controller. The primary storage controller determines occurrence of at least one condition in the primary storage controller, wherein the at least one condition occurs prior to a failure of the host to perform an Input/Output (I/O) operation with respect to at least one storage volume of the primary storage controller. The primary storage controller communicates the occurrence of the at least one condition to the host, wherein in response to the communicating the host is configured to determine whether to use the secondary storage controller instead of the primary storage controller based on the occurrence of the at least one condition.

Abstract: An approach to multiprotocol ACL implementation with guaranteed protocol compliance is described. In one approach, a method of access rights validation for a multiprotocol supported file server is detailed. The method involves receiving a request to store a file with a security descriptor and storing the security descriptor in an extended attribute associated with the file. Subsequently, the security descriptor is expanded to extract a set of ACEs. Access to the file can then be validated against the ACEs expanded from the security descriptor according to the specifications of the protocol that created the security descriptor.

Abstract: Techniques are disclosed for restoring a system volume on a computing system without requiring the system volume to be fully restored prior to being used or requiring the use of a dedicated recovery environment (e.g., the WinPE or BartPE environments). Instead, the computing system is booted directly from the restore image or by redirecting I/O interrupts to the restore image. That is, when user initiates a restore process, the system boots from the backup itself. Once booted, a background process can complete the restore process.

Abstract: A primary storage controller is maintained in a copy relationship with a secondary storage controller, wherein the primary and secondary storage controllers are coupled to a host that is configurable to use the secondary storage controller instead of the primary storage controller. The primary storage controller determines occurrence of at least one condition in the primary storage controller, wherein the at least one condition occurs prior to a failure of the host to perform an Input/Output (I/O) operation with respect to at least one storage volume of the primary storage controller. The primary storage controller communicates the occurrence of the at least one condition to the host, wherein in response to the communicating the host is configured to determine whether to use the secondary storage controller instead of the primary storage controller based on the occurrence of the at least one condition.

Abstract: There is provided a storage system and a method of identifying delta-data therein between two points-in-time. The method comprises: generating successive snapshots Si and Si+1 corresponding to the two points-in-time; upon generating the snapshot Si+1, searching the cache memory for data blocks associated with snap_version=i, thereby yielding cached delta-metadata; searching the SF mapping data structure for destaged data blocks associated with snap_version=i, thereby yielding destaged delta-metadata; and joining the cached delta-metadata and the destaged delta-metadata, thereby yielding delta-metadata indicative of the delta-data between points-in-time corresponding to the successive snapshots with Snap_ID=i and Snap_ID=i+1. The method operates with no need in copying, destaging to a dedicated location and/or any other special handling of data that needs to be transmitted to the RS system.

Abstract: In one embodiment, a system includes a processor and logic integrated with and/or executable by the processor, the logic being configured to cause the processor to access a snapshot of data stored on one or more DR clusters within a disaster recovery (DR) family only when the snapshot was made consistent with respect to data on one or more production clusters within the DR family before a time-zero, and perform DR testing using the snapshot, wherein the time-zero represents a time selected to simulate a disaster, wherein the DR family includes one or more DR clusters accessible to a DR host and the one or more production clusters accessible to a production host, and wherein the DR host is configured to replicate data from the one or more production clusters to the one or more DR clusters.

Abstract: Embodiments of the present invention provide an approach for providing cluster-aware (storage) resource provisioning in a networked computing environment (e.g., a cloud computing environment) based upon policies, best practices, and/or storage cluster/environment configurations. In a typical embodiment, a set of characteristics (e.g., computing resources/components, etc.) of a storage environment will be determined. A set of requirements for a set of workloads to be processed by the components of the storage environment will then be identified. A set of policies and a set of best practices will then be determined to identify a configuration of the storage environment to optimize the processing of the set of workloads according to the set of requirements. Based on the configuration, a plan will be generated that indicates a data path through the set of computing resources that minimizes a potential for error in processing the set of workloads.

Abstract: Methods, systems, and computer program products for providing deferred replication of recovery information at site switchover are disclosed. A computer-implemented method may include receiving a first copy of logged data for storage volumes of a disaster recovery (DR) partner at a remote site from the DR partner, receiving a request to perform a site switchover from the remote site to the local site, receiving a second copy of logged data for the storage volumes from a local high availability (HA) partner in response to the switchover, and recovering the storage volumes locally by applying one or more of the copies of logged data to corresponding mirrored storage volumes at the local site.

Abstract: An information processing device includes a plurality of arithmetic processing devices, a plurality of storage devices, a connection section that connects a first arithmetic processing device to a first storage device and a second storage device which are duplexed and a control section that causes, when the performance of the second storage device is reduced, the connection section to cut out the second storage device whose performance has been reduced from the first arithmetic processing device and the first storage device, causes to duplex a third storage device with the first storage device, causes the connection section to connect the first storage device and the third storage device which have been duplexed to the first arithmetic processing device and to connect a second arithmetic processing device to the second storage device that has been cut out, and causes the second arithmetic processing device to initialize the second storage device.

Abstract: Techniques to backup collaboration server data are disclosed. An indication to begin backup of a collaboration server dataset is received. An associated directory is walked in a prescribed order to divide the dataset into a prescribe number of approximately equal-sized subsets. A separate subset-specific thread is used to back up the subsets in parallel. In some embodiments in which the collaboration data is stored in multiple volumes, a volume-based approach is used to back up the volumes in parallel, e.g., one volume per thread. In some embodiments, transaction logs are backed up in parallel with volumes of collaboration data.

Abstract: A processing apparatus comprising: several processors for processing data; a hierarchical memory system comprising a memory accessible to all the processors, and several caches corresponding to each of the processors, each of the caches being accessible to the corresponding processor and comprising storage locations and corresponding indicators. There is also cache coherency control circuitry for maintaining coherency of data stored in the hierarchical memory system. The processors are configured to respond to receipt of a predefined request to perform an operation on a data item to determine if the cache corresponding to the processor receiving the request has a storage location allocated to the data item. If not, the processing apparatus is configured to: allocate a storage location within the cache to the data item, set the indicator corresponding to the storage location to indicate that the storage location is storing a delta value, set data in the allocated storage location to an initial value.

Abstract: Apparatus and methods for wireless systems provide a mechanism to enhance the communication capabilities of wireless users. In an embodiment, a server includes a processor that manages information in a database of the server, regulates, using instructions of a policy service in the server, communication of information from each of the clients to other entities, maintains reconfiguration policy with instructions having a sequencing procedure to provide the configuration data and a hierarchy identifying which of the clients controls re-supplying the configuration data to the server, controls, using instructions of a share agent in the server in conjunction with the instructions of the policy service, dissemination of information to one or more of the clients from the database on a shared basis, and manages the database, the router, the policy service, and the share agent using the processor in the server.

Abstract: Data storage systems and methods for storing data are described herein. The storage system may be integrated with or coupled with a compute cluster or super computer having multiple computing nodes. A plurality of nonvolatile memory units may be included with computing nodes, coupled with computing nodes or coupled with input/output nodes. The input/output nodes may be included with the compute cluster or super computer, or coupled thereto. The nonvolatile memory units store data items provided by the computing nodes, and the input/output nodes maintain where the data items are stored in the nonvolatile memory units via a hash table distributed among the input/output nodes. The use of a distributed hash table allows for quick access to data items stored in the nonvolatile memory units even as the computing nodes are writing large amounts of data to the storage system quickly in bursts.

Abstract: Certain example embodiments relate to white-box testing techniques, e.g., for graphical user interfaces (GUIs). Responsive to a first parameter received from a test suite executer, test bootstrap code included in an application is executed, where the application and the test suite executer run in the same browser. A test case to be run on the application and a test case executer to execute the test case are retrieved by the executed test bootstrap code. The retrieved test case is executed in a same context of the browser as the application. Results from executing the test case are stored.

Abstract: Provided are a computer program product, system, and method for asynchronous pausing of the formation of consistency groups. A first copy operation is initiated to copy the source data from the first storage to the first data copy in the second storage. A second copy operation is initiated to copy the first data copy in the second storage to a second data copy in response to forming a consistency group of the source data at the first data copy forms consistent as of a point-in-time with respect to the source data. The first copy operation is suspended to allow for further processing of the first data copy in response to completing the second copy operation. The formation of a next consistency group is restarted between the source data and the first data copy in response to receiving a resume command.

Abstract: A system, method, and computer readable medium for asynchronous live migration of applications between two or more servers. The computer readable medium includes computer-executable instructions for execution by a processing system. Primary applications runs on primary hosts and one or more replicated instances of each primary application run on one or more backup hosts. Asynchronous live migration is provided through a combination of process replication, logging, barrier synchronization, checkpointing, reliable messaging and message playback. The live migration is transparent to the application and requires no modification to the application, operating system, networking stack or libraries.

Abstract: Preventing a rollback attack in a computing system that includes a primary memory bank and a backup memory bank, including during startup of the computing system: determining whether the computing system is attempting to use firmware in the backup memory bank; responsive to determining that the computing system is attempting to use firmware in the backup memory bank, determining whether the firmware in the backup memory bank is a previous version of firmware in the primary memory bank; responsive to determining that the firmware in the backup memory bank is a previous version of firmware in the primary memory bank, determining whether a system administrator has authorized the use of the firmware in the backup memory bank; and responsive to determining that the system administrator has authorized the use of the firmware in the backup memory bank, configuring the computing system to utilize the firmware in the backup memory bank.

Abstract: Clustered storage systems and methods are presented herein. One clustered storage system includes a logical volume comprising first and second pluralities of storage devices. The first plurality of storage devices is different from the second plurality of storage devices and includes at least the same data as the second plurality of devices. The storage system also includes a first storage node operable to process first I/O requests to the first plurality of storage devices and a second storage node communicatively coupled to the first storage node and operable to process second I/O requests to the second plurality of storage devices. An I/O request of the first I/O requests initiates a redirection condition that the first storage node detects. Then, based on the redirection condition, the first storage node directs the second storage node to process data of the I/O request.

Abstract: A method comprising managing persistent messaging data in a volatile memory of a primary instance of a multi-node server, wherein the persistent messaging data is stored in a Hard Disk Device (HDD) and a Fast Persistent Memory (FPM) of the primary instance, repeatedly replicating the persistent messaging data to a corresponding HDD and a corresponding FPM of at least one standby instance of the multi-node server, repeatedly copying the persistent messaging data stored in the FPM or the HDD of the at least one standby instance to a Recovery Memory Region (RMR) in a volatile memory of the at least one standby instance, and responsive to a failure of the primary instance, initiating a failover procedure by the standby instance, wherein the failover procedure comprises reading at least some of the persistent messaging data from the RMR in lieu of the HDD of the at least one standby instance.

Abstract: Exemplary methods, apparatuses, and systems include a first host system configuring storage of the first host to serve as a primary cache for a virtual machine running on the first host. A second host system configures storage of the second host to serve as a secondary cache and boots a placeholder virtual machine. The first host transmits, in response to write operations from the virtual machine directed to the primary cache, copies of the write operations to the second host to create mirrored copies on the secondary cache. The first host acknowledges each write operation from the virtual machine when the write operation is committed to both the primary cache and the secondary cache. When the virtual machine is restarted on the second host in response to a failure or migration event, the secondary cache is promoted to serve as a new primary cache for the virtual machine.

Abstract: Nodes allocate auxiliary data blocks that are the backup of main data blocks to the nodes in a distributed manner. Each node that holds auxiliary data blocks stores therein management information indicating correspondences between the main data blocks corresponding to the auxiliary data blocks held by the own node and nodes holding the main data blocks.

Abstract: Disclosed herein are systems, methods, and non-transitory computer-readable storage media for using an intermediate database management layer to manage communications between an application layer and a database layer. The database management layer can receive an initial communication from the application layer and transmit a subsequent communication to a particular database based upon a rule. The rules can specify the particular database based upon the initial communication and an availability status of the database. The rules specify criteria by which the initial communication is identified and logic specifying the particular database to receive the subsequent communication based upon the identification of the initial communication.

Abstract: Placing an application on a node in a cluster. A method includes detecting an unexpected event indicating that an application should be placed on a node in the cluster. Real time information about resource utilization on one or more nodes in the cluster is received. Based on the real time information, a determination of a node to place the application is made. The application is placed on the determined node.

Abstract: In a hybrid memory system that includes a host memory controller and a non-volatile memory DIMM, where the DIMM is coupled to the host memory controller by a memory bus, the DIMM includes non-volatile memory, a DIMM bus adapter, and a local memory controller, the local memory controller is configured to control memory accesses within the DIMM, the DIMM bus adapter is configured to adapt the local memory controller to the bus for memory communications with the host memory controller in accordance with a bus protocol, bus resiliency may be provided by: discovering, by the DIMM bus adapter, a memory error in the DIMM; providing, by the DIMM bus adapter to the host memory controller, an indication of an error by emulating a hardware error native to the bus protocol; and performing, by the host memory controller, one or more resiliency measures responsive to the indication of the error.

Abstract: Crash recovery of a computing system in the context in which the computing system includes a volatile memory which has contents lost due to the crash, an intermediate non-volatile memory that (together with the volatile memory) contributes to the active memory of the computing system, and non-volatile storage. The recovery occurs by identifying pages that were in the volatile memory at the time of the crash. For each of these pages, the recovery determines whether to recover the page into the volatile memory from either the intermediate non-volatile memory or the storage, and then performs the recovery. In embodiments in which access speeds for the intermediate non-volatile memory may be much faster than for the storage, and in which much of the pages to be recovered are recovered from the intermediate non-volatile memory, the recovery time may be reduced.

Abstract: A method of operating a remote procedure call cache in a storage cluster is provided. The method includes receiving a remote procedure call at a first storage node having solid-state memory and writing information, relating to the remote procedure call, to a remote procedure call cache of the first storage node. The method includes mirroring the remote procedure call cache of the first storage node in a mirrored remote procedure call cache of a second storage node. The storage cluster includes the first storage node and the second storage node. The storage system includes the first storage blade and the second storage blade. A storage node and a storage cluster are also provided.

Abstract: A survey tool for use in a Recover to Cloud (R2C) replication service environment that determines configuration information automatically (such as through SNMP messaging or custom APIs) and stores it in a survey database. A Virtual Data Center (VDC) representation is then instantiated from the survey database, with the VDC being a virtual replica of the production environment including dormant Virtual Machine (VM) definition files, applications, storage requirements, VLANs firewalls, and the like. The survey tool determines the order in which the replicas are brought on line to ensure orderly recovery, by determining the order in which each machine makes requests for connections to other machines.

Abstract: A computerized method for sharing removable storage media in a network, the method comprising associating, in an index entry, a first piece of removable storage media in a first storage device with at least a first storage policy copy and a second storage policy copy; copying, to the first piece of removable storage media, data associated with the first storage policy copy; and copying, to the first piece of removable storage media, data associated with the second storage policy copy.

Abstract: In a backup method, a source storage device sends data to a backup storage device. The source storage device contains a processor and a cache. The processor receives a write data request which includes target data. And then, the processor reads a first period ID recorded in a period ID table, wherein the first period ID is corresponding to a first period. Next, the processor modifies the write data request by attaching the first period ID to the target data and writes the modified write data request into the cache. After a backup task corresponding to the first period is triggered, the processor identifies a second period ID. The second period ID corresponds to a previous period up to which data received by the source storage device have been duplicated to the backup storage device. And then, the processor obtains data received after the period corresponding to the second period ID and up to the first period and sends the obtained data to the backup storage device.

Abstract: A NAS device providing a snapshot function for executing CoW processing in multiple successive block units is provided, wherein upon restoring a file saved in a file system sharing from a snapshot, the speed for restoring files is enhanced by restoring only data blocks that have been changed within the data blocks constituting a file, to thereby reduce the amount of data being restored and cut down CoW processing. Upon restoring a file stored in file system sharing from a snapshot file, data blocks storing different data between the restore source file and the restore destination file are specified based on a differential map table and a differential block table, and only the specified data blocks are restored. Further, upon restoring data from a file other than the snapshot, the data blocks constituting the restore source file and the restore destination file are compared, and only the data blocks storing different data are restored.

Abstract: Techniques for data backup and recovery are described. In one implementation, at least one storage device storing original data which has failed is determined. Once the failed storage device is determined, backup related information corresponding to the failed at least one storage device is determined. Based on the backup related information at least one backup of the original data from a storage unit is identified. The backup as identified is eventually used for recovering data corresponding to the original data.

Abstract: One embodiment is a system, comprising a first NAS device, a second NAS device. The first and second NAS devices may be configured to be paired with one another to enable an ongoing secure exchange of content (e.g., files, pictures, movies, audio recordings) and NAS settings (e.g., RAID settings, backup schedules, etc.) between the first and second NAS devices across a network. According to one embodiment, through this ongoing secure exchange of content and NAS settings, the second NAS device may become and may be thereafter maintained as a mirror of the first NAS device, such that the second NAS device may be maintained as a drop-in physical and functional replacement for the first NAS device in the event of a failure of the first NAS device.

Abstract: A method is used in recovering file system blocks of file systems. A first read error is encountered upon reading a file system block of a file system. The file system block includes a first set of chunks. A second read error is encountered upon reading a duplicate copy of the file system block. The duplicate copy of the file system block includes a second set of chunks. Each chunk of the first and second sets of chunks is evaluated. Based on the evaluation, the file system block is recovered.

Abstract: Aspects of the subject matter described herein relate to database connectivity behavior. In aspects, an entity seeking to access data that is replicated via instances of a database follows a plan. The plan provides information as to which instance(s) the entity is to attempt to access the data from. The plan may include connection data that indicates parameters the entity is to use in connecting to the instance(s). The plan may also indicate one or more other instances from which the entity may attempt to access the data if the client is not able to access the data from initial instance(s).

Abstract: Mechanisms for controlling access to storage volumes on the secondary storage system is provided. A determination is made as to whether a first site computing device has sent a notification of a failure condition of a first site. In response to a determination that the notification of the failure condition of the first site has not been received, secondary workloads of a second site computing device are permitted to access storage volumes on the secondary storage system. In response to a determination that the notification of the failure condition of the first site has been received, a mode of operation of the second site is modified from a normal mode of operation to a failure mode of operation. In the failure mode of operation, the storage system controller of the second site blocks at least a portion of access requests from secondary workloads of the second site computing device.

Abstract: A method, computer program product, and computing system for receiving an indication that a hard disk drive within a data array is failing, thus defining a failing hard disk drive. At least a portion of the data included within the failing hard disk drive is copied to a failover portion of a front end cache system included within a host coupled to the data array, thus defining a backup data set.

Abstract: According to one embodiment, a memory system includes a first memory, a second memory, and a control unit. The first memory includes a volatile first register retaining a first operation parameter. The control unit performs a first operation of retaining the first operation parameter in the second memory. Then, the control unit turns OFF the first memory while retaining the first operation parameter in the second memory when an operation mode is switched from a first mode to a power saving second mode. Then, the control unit performs a second operation of turning on the first memory, and transferring the first operation parameter retained in the second memory to the first register when the operation mode is switched from the second mode to the first mode.

Abstract: A data migration operation uses an error flag to protect against data corruption. During write cloning states, the error flag is set and only allowed state transitions are performed, including a non-error transition to a committed state when no device fault is recorded for a target storage device and an error transition to a setup state when a device fault is recorded for the target storage device. In a clean system shutdown, a shutdown procedure records a detected target storage device fault and clears the error flag; the recorded device fault later forces the error transition of the migration operation. During the system startup, if the error flag is set then a target storage device fault is recorded to likewise later force the error transition of the migration operation, on the assumption that a detected fault may exist but be unrecorded because the shutdown procedure did not complete during shutdown.

Abstract: A disaster recovery appliance is described herein. The disaster recovery appliance is coupled to one or more servers. The disaster recovery appliance continuously receives backup data for each of the one or more servers. When a server fails, the disaster recovery appliance, replaces the failed server. While the failed server is inaccessible, the disaster recovery appliance is able to mimic the functionality of the failed server. In some embodiments, the disaster recovery appliance is able to act as a server in addition to a backup device for the other servers.

Abstract: In response to detecting a failure on a secondary storage device, a transmission of a data write request to the primary storage device is suspended. Identifying an outstanding data write request, wherein the outstanding data write request has been performed by the primary storage device, but has not been performed by a disaster recovery (DR) storage device. Instructing the DR storage device to update data on the DR storage device according to the identified outstanding data write request. Setting the primary storage device to enable the primary storage device to forward a subsequently received data write request to the DR storage device. And restoring the transmission of the data write requests to the primary storage device.

Abstract: A system and method are disclosed for managing a plurality of virtual machines (VMs) in a fault-tolerant and low-latency manner. In accordance with one example, a computer system executes a first VM and a second VM, and creates a first live snapshot of the first VM and a second live snapshot of the second VM. The computer system detects, after the creating of the first live snapshot and the second live snapshot, a failure that affects the executing of the first VM, and in response destroys the first VM and the second VM, creates a third VM from the first live snapshot and a fourth VM from the second live snapshot, and initiates execution of the third VM and the fourth VM. An output transmitted by the first VM to the second VM during the creating of the first live snapshot and the second live snapshot is not blocked.

Abstract: A method, system and computer program product are provided for implementing enhanced data caching and takeover of non-owned storage devices in a computer system. Each of a first controller and a second controller has a cache memory. During normal run-time, each storage device controller validates cached write data after it is written to its cache memory by reading the write data from its cache memory. If any error is detected on the read, then unit check failed storage device controller, which results in a reset of the failed storage device controller. When a storage device controller detects its dual partner controller fails, the surviving storage device controller queues host read/write operations for its storage devices already owned, and tests a cache mirrored copy from its cache memory of the failed first storage device controller before takeover of the failed controller's storage devices.

Abstract: A system and method for power management of storage resources are disclosed. A method may include detecting an occurrence of an event associated with a storage resource disposed in an array of storage resources. The method may further include transitioning the storage resource into a specified power state in response to the detection of the occurrence of the event. A system may include a storage resource and a power management module communicatively coupled to the storage resource. The storage resource may be disposed in an array of storage resources. The power management module may be operable to detect an occurrence of an event associated with the storage resource, and may be operable to transition the storage resource into a specified power state in response to the detection of the occurrence of the event.

Abstract: Exemplary method, system, and computer program product embodiments for optimizing disaster recovery systems during takeover operations are provided. In one embodiment, by way of example only, a flag is set in a replication grid manager to identify replication grid members to consult in a reconciliation process for resolving intersecting and non-intersecting data amongst the disaster recovery systems for a takeover operation. The replication grid members are consulted for the takeover operation to accommodate a coordination of an ownership synchronization process for cartridges not distributed on-time to the replication grid members. Additional system and computer program product embodiments are disclosed and provide related advantages.

Abstract: Technologies are described herein for providing a two-tier failover service. A request to access content by an application associated with an application identifier may be identified. A first record corresponding to the application identifier may be retrieved from a database information table. The first record may include a reference identifier, a database name of a database, and a failover value. A second record corresponding to the reference identifier may be retrieved from a server information table. The second record may include an indication of a first server computer as a primary server computer and an indication of a second server computer as a secondary server computer. A connection specification to either the first server computer or the second server computer may be generated based on the first record and the second record.

Abstract: A storage device and memory accessing method configure two separate memory units, each with dedicated I/O channel, accessible by two controllers, each corresponding to an interface connected to a host, and allows the storage device to establish at least two connections to the different hosts. As more than one connection is established between the storage device and the hosts at the same time, a first controller has both read and write accessibility to a first memory unit and a second controller has both read and write accessibility to a second memory unit, while the first controller has read-only accessibility to the second memory unit and the second controller has read-only accessibility to the second memory unit.

Abstract: In one embodiment, an indication of a fault condition is received relating to a first service running on a physical device in a computer network. The first service is associated with a first virtual device context defined on the physical device. Then, the first service is disabled without affecting operation of a second service on the physical device. The second service is associated with a second virtual device context defined on the physical device. In another embodiment, a first virtual device context is created on a physical device in a computer network. Then, a second virtual device context is created on the physical device. The first virtual device context may then be managed independently of the second virtual device context such that resources assigned to a virtual device context are managed without affecting management of another virtual device context.

Abstract: The disclosed embodiments relate to systems and methods for coordinating management of a shared disk storage between nodes. Particularly, a messaging protocol may be used to communicate notifications regarding each node's perception of the shared storage's state. The nodes may use the messaging protocol to achieve consensus when recovering from a storage device failure. Some embodiments provide for recovery when localized failures, such as failures at an adapter on a node, occur.