Abstract: Mirroring of a logical storage unit initially associated with a first controller is performed, where the first log segment associated with the first controller is maintained of writes by the first controller to the logical storage unit. The first log segment is for use in mirroring writes to a mirror system. Control of the logical storage unit is transferred from the first controller to at least a second controller, and in response to the transfer, a first marker is provided in the first log segment to enable the mirror system to synchronize mirrored writes corresponding to writes to the logical storage units by the first controller and at least a second controller.

Abstract: In a storage system, at least three storage sites are arranged in a full mirroring relationship using a virtual connection between instances of a storage group on two of the sites whereby no user data is transmitted.

Abstract: A client-server based Storage Area Network (SAN) management system provides easy to use and uniform multiple user interfaces such as web interface and windows interface to the administrators to manage the SAN consisting of various types of devices. The integrated object-oriented management agent consists of several components such as object manager, UI module, web server, user interface modules, error and status handler and device handler. The agent functionality can be dynamically expanded to handle new device types without stopping the existing agent, installing new agent and restarting it. The management system uses conglomerate methods to automatically discover SAN devices and their topology. The error and status from SAN devices are handled in a hybrid method consisting of distributed, hierarchical and centralized schemes. A simple and easy device independent user interface is provided to download firmware to various types of devices hiding complex device dependent processes from the administrator.

Abstract: Mirroring of a logical storage unit initially associated with a first controller is performed, where the first log segment associated with the first controller is maintained of writes by the first controller to the logical storage unit. The first log segment is for use in mirroring writes to a mirror system. Control of the logical storage unit is transferred from the first controller to at least a second controller, and in response to the transfer, a first marker is provided in the first log segment to enable the mirror system to synchronize mirrored writes corresponding to writes to the logical storage units by the first controller and at least a second controller.

Abstract: Systems and methods for asynchronous backup of virtual disks in a distributed storage array are disclosed. An exemplary method may comprise receiving an IO stream at the virtual disks in the distributed storage array, writing data to one or more storage cells of the virtual disks in the distributed storage array, and logging completed writes in a first batch for each of the one or more storage cells. The method also comprises establishing a consistency point in the IO stream, terminating logging to the first batch for each of the one or more storage cells at the consistency point and logging completed writes after the consistency point to a new batch for each of the one or more storage cells. The method also comprises transferring writes logged in the first batch to at least one remote storage so that the at least one remote storage is crash consistent.

Abstract: Systems and methods for asynchronous backup of virtual disks in a distributed storage array are disclosed. An exemplary method may comprise receiving an IO stream at the virtual disks in the distributed storage array, writing data to one or more storage cells of the virtual disks in the distributed storage array, and logging completed writes in a first batch for each of the one or more storage cells. The method also comprises establishing a consistency point in the IO stream, terminating logging to the first batch for each of the one or more storage cells at the consistency point and logging completed writes after the consistency point to a new batch for each of the one or more storage cells. The method also comprises transferring writes logged in the first batch to at least one remote storage so that the at least one remote storage is crash consistent.

Abstract: Systems and methods for asynchronous backup of virtual disks in a distributed storage array are disclosed. An exemplary method may comprise receiving an IO stream at the virtual disks in the distributed storage array, writing data to one or more storage cells of the virtual disks in the distributed storage array, and logging completed writes in a first batch for each of the one or more storage cells. The method also comprises establishing a consistency point in the IO stream, terminating logging to the first batch for each of the one or more storage cells at the consistency point and logging completed writes after the consistency point to a new batch for each of the one or more storage cells. The method also comprises transferring writes logged in the first batch to at least one remote storage so that the at least one remote storage is crash consistent.

Abstract: In one embodiment, a method for bitmap based synchronization of a source volume and a target volume comprises obtaining, in a source controller, a synchronization timestamp, and for one or more bits in a bitmap representing the source volume, transmitting a synchronization request to the target volume, wherein the synchronization request comprises the synchronization timestamp, receiving a reply from the target volume, and clearing the bit in the bitmap in response to the reply from the target volume.

Abstract: Systems and methods for asynchronous backup of virtual disks in a distributed storage array are disclosed. An exemplary method may comprise receiving an IO stream at the virtual disks in the distributed storage array, writing data to one or more storage cells of the virtual disks in the distributed storage array, and logging completed writes in a first batch for each of the one or more storage cells. The method also comprises establishing a consistency point in the IO stream, terminating logging to the first batch for each of the one or more storage cells at the consistency point and logging completed writes after the consistency point to a new batch for each of the one or more storage cells. The method also comprises transferring writes logged in the first batch to at least one remote storage so that the at least one remote storage is crash consistent.

Abstract: In a storage system, at least three storage sites are arranged in a full mirroring relationship using a virtual connection between instances of a storage group on two of the sites whereby no user data is transmitted.

Abstract: A method, of validating the configuration of a storage system (SS) via comparison of a snapshot thereof (SSshot) against a desired storage system architecture (SS-architecture) where the storage system includes an interconnected plurality of devices, may include: providing a database representing the desired SS-architecture, the database including a first listing of permissible types of device within the storage system and a second listing of permissible instances of the device types within the storage system; automatically determining, for each device in the SSshot, whether a device type thereof is acceptable based upon the first listing; and automatically determining, at least for each permissible type of device in the SSshot, whether instance details thereof are permissible based upon the second listing.

Abstract: A method, of modeling a storage system that includes an interconnected plurality of devices where there is at least one instance of a multi-link rather than a single-link between two of the plurality of devices, may include: providing a snapshot of the storage system (SSshot); decomposing multi-links of the SSshot into single-link-based arrangements, respectively; associating the single-link-based arrangements with the multi-links, respectively; and modeling the storage system as a graph of singly-linked nodes based upon the SSshot and the associated single-link-based arrangements, where nodes of the graph correspond to the plurality of devices.