Abstract: A storage array presents virtual arrays to hosts through use of virtual port IDs. The storage array includes groups of logical units of storage. The groups are coupled to a switch through at least one physical port. Each group is assigned a unique virtual port ID for each physical port to which it is coupled. The virtual port IDs are assignable by the switch. The virtual port IDs are used by hosts coupled to the switch to exchange data with the groups to which the virtual port IDs are assigned. Further, a zoning table in the switch can associate each virtual port ID to a host facing port on the switch. In this case each host can communicate only with groups of logical units that are assigned virtual IDs associated with the host facing port to which it is coupled.

Abstract: Non-disruptive data migration from a source array to a destination array entails generating a virtual array spanning at least one destination array for receiving a copy of all data at the source array. The virtual array has at least as many virtual ports as physical source ports of the source array and at least as many logical units (LUNs) as the source array. Each source array LUN corresponds to a virtual array LUN and equals the storage capacity of that corresponding LUN. Each virtual port has a virtual port address. All data resident in the LUNs of the source array are copied to corresponding LUNs in the virtual array. A name server database is reconfigured to associate port names of the physical source ports with the virtual port addresses of the virtual ports such that the virtual array appears to a host as the source array.

Abstract: Described is non-disruptive data migration from a source virtual array at a source storage array to a target virtual array at a heterogeneous destination storage array. A name server database is queried to obtain port names for each source port. The source storage array is queried to obtain information about each source virtual array LUN. A target virtual array is generated at the destination array for receiving a copy of data resident at the source virtual array. The target virtual array has at least as many ports and at least as many LUNs as the source virtual array. Data resident in the source virtual array LUNs are copied to corresponding target virtual array LUNs. The name server database is reconfigured to associate source port names with the virtual port addresses of the target virtual array such that the target virtual array appears to a host as the source virtual array.

Abstract: Described is non-disruptive data migration from a source array to a heterogeneous destination array. A name server database is queried to obtain port names for each source array port. The source array is queried to obtain information about each source array LUN. A target array is generated at the destination array for receiving a copy of data resident at the source array. The target array has at least as many ports and at least as many LUNs as the source array. Each source array LUN corresponds to a target array LUN and is equal in storage capacity as that corresponding LUN. All data resident in the source array LUNs are copied to corresponding target array LUNs. The name server database is reconfigured to associate source port names with the port addresses of the target array such that the target array appears to a host as the source array.

Abstract: A data storage system having a host computer/server coupled to a bank of disk drives through an interface. The bank of disk drives has a plurality of disk units, each one of such disk drive units having a magnetic storage media. The interface includes: a plurality of front-end directors coupled to the host computer/server; a plurality of back end directors coupled to the disk drive units; and, a global cache memory available for caching user data for the plurality of disk drives. The global cache memory comprises a plurality of non-volatile memory global cache memory sections distributed among disk drive units within the bank of disk drive units. The non-volatile memory global cache memory sections are connected to the back-end directors. Each one of the non-volatile memory global cache memory sections caches user data for the magnetic storage media of the plurality of disk drive units independent of the one of the disk drive units having such one of the non-volatile memory global cache memory sections.

Abstract: Described are systems and methods of migrating data from a source array to a destination array transparently with respect to a management application program executing on a host system and using management information to send management messages to the storage arrays. Data are copied from the source array to the destination array during a data migration event. A first array management interface is associated with the source array and a second array management interface is associated with the destination array. Each array management interface includes management information that a management application executing on the host can use to communicate with the storage array. The first and second array management interfaces are exchanged during the data migration event so that the array management interface associated with the destination array becomes associated with the source array and the array management interface associated with the source array becomes associated with the destination array.

Abstract: Described are a system and method of presenting virtual arrays in a storage network. A physical storage array is partitioned into a plurality of virtual arrays. Each virtual array has logical units of storage. Each virtual array is associated with a virtual array management interface by which a management application executing remotely on a host can address communications separately to that virtual array for managing the logical units of storage of that virtual array.

Abstract: Described are a system and method of migrating data stored logical units of storage (LUNs) at a source storage array to a plurality of destination storage arrays transparently with respect to a host in communication with the source storage array through a switch. The source storage array is divided into a plurality of source virtual arrays including a first source virtual array and a second source virtual array. Each destination storage array is divided into one or more destination virtual arrays. During a data migration event, data stored in a LUN of the first source virtual array are copied to a corresponding LUN of a destination virtual array of a first one of the destination storage arrays, and data stored in a LUN of the second source virtual array are copied to a corresponding LUN of a destination virtual array of a second one of the destination storage arrays.

Abstract: Described are a system and method of migrating data stored in logical units of storage (LUNs) at a plurality of source storage arrays into one destination storage array transparently with respect to a host in communication with the source storage arrays through a switch. First and second source storage arrays and a destination storage array are each partitioned into a plurality of source virtual arrays. The destination virtual arrays include a first destination virtual array and a second destination virtual array. Data stored in a LUN of a first source virtual array of the first source storage array are copied to a corresponding LUN of the first destination virtual array of the destination storage array, and data stored in a LUN of a second source virtual array of the second source storage array are copied to a corresponding LUN of the second destination virtual array of the destination storage array.

Abstract: Described are a storage network and method of migrating data from a source virtual array to a destination virtual array transparently with respect to a storage application executing on a host. The storage application provides particular storage functionality at a source storage array while using metadata during its execution. The metadata used by the storage application are associated with the source virtual array and forwarded, during a data migration event in which data resident in logical units of storage (LUNs) of the source virtual array are copied to LUNs of the destination virtual array, to a destination storage array where the metadata is associated with the destination virtual array.

Abstract: Scheduling jobs for a plurality of logical devices associated with physical devices includes assigning a physical run count value and a physical skip count value to each of the physical devices, at each iteration, examining the physical skip count value and the physical run count value for each of the physical devices, and scheduling a number of jobs up to the physical run count value for logical devices associated with a particular one of the physical devices at each iteration corresponding to the physical skip count value for the particular one of the physical devices. The physical skip count value and the physical run count value for a particular one of the physical devices may vary according to a total load of the particular physical device.

Abstract: A method is used in handling sector edges. Input/output (I/O) requests to a storage device are handled. The I/O requests use a different sector size format than that of the storage device. An I/O request is received for a write operation at a logical address of a virtual device. The write operation specifies new data to be written to the virtual device. A logical sector associated with the logical address is determined. The logical sector is mapped to a portion of a physical sector of the storage device. The sector edge of the physical sector is read into a RAID-protected memory. The read sector edge is written together with the new data to the storage device.

Abstract: Scheduling jobs for a plurality of devices includes assigning a run count value to each of the devices, scheduling a number of consecutive jobs up to the run count value, and decrementing the run count value according to the number of consecutive jobs scheduled. The run count value for a particular one of the devices may vary according to a total load of the particular one of the devices. The total load of the particular device may vary according to a number of pending jobs for the particular device and a total number of jobs for all devices coupled to a controller for the devices. The devices may be disk drive devices. Only one read job may be scheduled for a device irrespective of the run count value for the device and devices having pending read jobs may be given precedence over other devices. Multiple read jobs may be scheduled for a device according to the run count value and devices having pending read jobs may be given precedence over other devices.

Abstract: Failover is provided from a primary Fiber Channel device to a secondary Fiber Channel device. Source and secondary Fiber Channel devices are coupled to a Fiber Channel fabric having a database that associates Fiber Channel names and Fiber Channel addresses of Fiber Channel ports coupled to it. All data is copied from the primary Fiber Channel device to the secondary Fiber Channel device. In response to a failure, secondary port names and LUN names are replaced with the primary port names and LUN names, and the fabric updates its database so that the database associates the secondary port and LUN addresses with the primary port and LUN names. The secondary Fiber Channel device thereby assumes the primary Fiber Channel device's identity.

Abstract: Described are techniques and criteria used in connection with cache management. The cache may be organized as a plurality of memory banks in which each memory bank includes a plurality of slots. Each memory bank has an associated control slot that includes groups of extents of tags. Each cache slot has a corresponding tag that includes a bit value indicating the availability of the associated cache slot, and a time stamp indicating the last time the data in the slot was used. The cache may be shared by multiple processors. Exclusive access of the cache slots is implemented using an atomic compare and swap instruction. The time stamp of slots in the cache may be adjusted to indicate ages of slots affecting the amount of time a particular portion of data remains in the cache. Each director may obtain a cache slot from a private stack of nondata cache slots in addition to accessing a shared cache used by all directors.

Abstract: Source and destination fiber channel devices are coupled to a fiber channel fabric. Hosts communicate with the fiber channel devices using fiber channel addresses. All data is copied from the source fiber channel device to the destination fiber channel device. Source port names and LUN names are exchanged with destination port names and LUN names so that the source device has the destination port and LUN names and the destination device has the source port and LUN names. The fabric reloads its name server database for use by the host(s) so that the database associates the source port and LUN names with the destination port and LUN names and the destination port and LUN names with the source port and LUN names. The names known to the host have not changed and the destination fiber channel device now appears to the host as the source fiber channel device.

Abstract: Described is a storage system and method for managing and optimizing power consumption in a storage system. Logical devices are mapped to physical disk drives. A plurality of power profiles is defined. Each power profile is associated with a mode of operation for a physical disk drive. One of the power profiles is assigned to each logical device. One of the physical disk drives is identified for which every logical device mapped to that physical disk drive has been assigned the same power profile. The identified physical disk drive is operated in the mode of operation associated with said same power profile. The mapping of the logical devices to the physical disk drives may be changed in order to group logical devices assigned the same power profile onto the same physical disk drive.

Abstract: Described is a storage system and method for reducing power consumption in a storage system by shortening seek distances associated with input/output (I/O) requests to a physical disk drive. A sweep direction is set. An offset of a new I/O request is evaluated to determine whether to send the new I/O request to the physical disk drive. The new I/O request is sent to the physical disk drive if the offset is consistent with the sweep direction. Otherwise, sending the new I/O request to the disk drive is deferred until the sweep direction is set to a reverse direction.

Abstract: Disk drive power states are managed. Information is received for use in determining a desired power state of a disk drive that is not currently being accessed. The disk drive is caused to have a spun up power state before the disk drive is next accessed.

Abstract: Described are systems and methods of migrating data from a source virtual array to a destination virtual array transparently with respect to a management application program executing on a host and using management information to send management messages to the virtual arrays. Data from the source virtual array are copied to the destination virtual array during a data migration event. First and second virtual array management interfaces are associated with the source and destination virtual arrays, respectively. The first and second virtual array management interfaces are exchanged during the data migration event so that the virtual array management interface associated with the destination virtual array becomes associated with the source virtual array and the virtual array management interface associated with the source virtual array becomes associated with the destination virtual array.