Storing recovery data includes providing chunks of data to a remote destination, where each chunk of data represents data written before a first time and after a second time and where the second time for one of the particular chunks corresponds to a first time for a subsequent one of the particular chunks, providing synchronous data to a local destination, and providing an indicator to the local destination in connection with creation of a new chunk of data for storage at the remote destination. The local destination may maintain a plurality of maps, where each of the maps associates synchronous data being provided thereto with a specific chunk of data. In response to receiving an indicator in connection with creation of a new chunk of data, the local destination may point to a new map. There may be two maps or more than two maps.

A data processing system configured to store a plurality of data entities in volatile memories of multiple different computing devices. The data processing system comprises a first computing device having a first volatile memory configured to store a first data entity; and a second computing device having a second volatile memory configured to store a copy of the first data entity. The first computing device is configured to perform: receiving an indication to update the first data entity; after receiving the indication, updating the first data entity in the first volatile memory, and providing to the second computing device an indication to update the copy of the first data entity; and providing an indication that the first data entity has been updated, after receiving information from the second computing device indicating that the copy of the first data entity has been updated in the second volatile memory.

In an approach for establishing metadata for one or more primary devices in a mirroring relationship, one or more computers systems generate a device validity token and establish a mirroring relationship, wherein the mirroring relationship includes identifying one or more primary devices of a plurality of devices in the mirroring relationship. The approach includes the computer systems sending the device validity token to each of a plurality of operating systems in the mirroring relationship for storage in a token store and retrieving a logical device identifier for each of the devices in the mirroring relationship. Furthermore, the approach includes the computer systems generating metadata for each of the primary devices, wherein metadata for each of the one or more primary devices includes at least the device validity token and the logical device identifier for each primary device of the one or more primary devices that generates the metadata.

Described are techniques and systems to migrate data from a first data structure to a second data structure stored in datastores which are replicated with one another. A hot datastore is replicated with one or more warm datastores. Triggers maintain consistency between the first data structure and the second data structure. Migration may involve testing using the second data structure of the warm datastore. Data processed by the first data structure on the hot datastore is distributed via replication to the warm datastore, and then by a trigger to the second data structure. Data processed by the second data structure on the warm datastore is distributed via trigger to the first data structure, and then by replication to the hot datastore. Once performance of the second data structure is deemed acceptable, the warm datastore may be designated as hot and synonyms therein may direct data to the second data structure.

One or more processing platforms are configured to implement at least a first site of a multi-site storage system. The first site comprises a first file system resident at the first site, and a replicated version of a second file system. The second file system is resident at a second site of the multi-site storage system, and the replicated version of the second file system is resident at the first site. Virtual block storage appliances running on respective virtual machines of the first site interact with one another and with similar appliances at the second site to allow the replicated version of the second file system to be synchronized at a cache level with the second file system, and to allow a replicated version of the first file system at the second site to be synchronized at a cache level with the first file system at the first site.

In one embodiment of the present description, mirroring is provided for a pair of storage units in bidirectional synchronous mirror relationships, and a tertiary storage unit. The mirroring includes multi-target mirroring to write updates written to the first storage unit to both the second storage unit and to a third storage unit. Similarly, for updates written to the second storage unit, multi-target mirroring is employed to write those to both the first storage unit and to the third storage unit. Other aspects are described.

Storing recovery data includes providing chunks of data to a remote destination, where each chunk of data represents data written before a first time and after a second time and where the second time for one of the particular chunks corresponds to a first time for a subsequent one of the particular chunks, providing synchronous data to a local destination, and providing an indicator to the local destination in connection with creation of a new chunk of data for storage at the remote destination. The local destination may maintain a plurality of maps, where each of the maps associates synchronous data being provided thereto with a specific chunk of data. In response to receiving an indicator in connection with creation of a new chunk of data, the local destination may point to a new map. There may be two maps or more than two maps.

A storage system according to one preferred embodiment of the present invention is composed of at least a first storage subsystem and a second storage subsystem. Write data from a host computer is duplicated to a first volume of the first storage subsystem and a second volume of the second storage subsystem, and the host computer is composed to be able to access both the first volume and the second volume. Attribute information which is information related to an order of write and/or write capability is set for each volume, and when an access command to the volume is received from the host computer, the storage subsystem determines whether I/O to the first volume and/or the second volume is required or not based on the attribute set for each volume.

Providing application-side infrastructure to control cross-region replicated object stores is disclosed. An embodiment includes determining, for an object store replicated across a plurality of storage systems at a plurality of locations, a minimum time interval between requests to modify the object store that are received by differing storage systems of the plurality of storage systems that ensures a predictable result on all storage systems among which the requested modifications are replicated; and providing, through an application programming interface (API) to a client that utilizes the object store, one or more object store parameters including the minimum time interval.

A system and method for enhanced fault detection of a component includes executing a component health assessment of a plurality of components of a computing node based on identifying the computing node as having an unhealthy state of health, wherein executing the component health assessment of the plurality of components includes: identifying a healthy computing node having a healthy state of health; establishing a plurality of distinct pairs of components, each distinct pair of components of the plurality of distinct pairs of components includes one component of the computing node and one component of the healthy computing node; and executing bi-directional testing by each of the plurality of distinct pairs of components; evaluating health assessment data generated based on the execution of the bi-directional testing; and classifying as faulty components of the plurality of components of the computing node based on the evaluation of the health assessment data.