Abstract: A rackmountable storage enclosure includes a chassis. The chassis includes one or more power supplies and a plurality of drawers, each extendable through a front surface of the chassis. Each drawer of the plurality of drawers provides mounting for one or more storage devices. All storage devices in any drawer of the plurality of drawers are inserted or removed through a common side of the drawer. Any storage device may be inserted or removed from any drawer of the plurality of drawers even if the side surfaces of the chassis are each parallel to and in contact with a wall, each of the walls extending forward at least to a fully extended length of any drawer. Electrical failures in any one drawer are prevented from affecting any other drawer of the plurality of drawers. The one or more power supplies provides DC power to the plurality of drawers.

Abstract: A network storage appliance is disclosed. The storage appliance includes a port combiner that provides data communication between at least first, second, and third I/O ports; a storage controller that controls storage devices and includes the first I/O port; a server having the second I/O port; and an I/O connector for networking the third I/O port to the port combiner. A single chassis encloses the port combiner, storage controller, and server, and the I/O connector is affixed on the storage appliance. The third I/O port is external to the chassis and is not enclosed therein. In various embodiments, the port combiner comprises a FiberChannel hub comprising a series of loop resiliency circuits, or a FiberChannel, Ethernet, or Infiniband switch. In one embodiment, the port combiner, I/O ports, and server are all comprised in a single blade module for plugging into a backplane of the chassis.

Abstract: A rackmountable storage enclosure includes a chassis. The chassis includes one or more power supplies and a plurality of drawers, each extendable through a front surface of the chassis. Each drawer of the plurality of drawers provides mounting for one or more storage devices. All storage devices in any drawer of the plurality of drawers are inserted or removed through a common side of the drawer. Any storage device may be inserted or removed from any drawer of the plurality of drawers even if the side surfaces of the chassis are each parallel to and in contact with a wall, each of the walls extending forward at least to a fully extended length of any drawer. Electrical failures in any one drawer are prevented from affecting any other drawer of the plurality of drawers. The one or more power supplies provides DC power to the plurality of drawers.

Abstract: A network storage appliance is disclosed. The appliance includes a chassis enclosing a backplane, and a server enclosed in the chassis and coupled to the backplane. The appliance also includes storage controllers enclosed in the chassis, each coupled to the backplane, which control transfer of data between the server and storage devices coupled to the storage controllers. The storage controllers also control transfer of data between the storage devices and computers networked to the appliance and external to the appliance. The storage controllers and the server comprise a plurality of hot-replaceable blades. Any one of the plurality of blades may be replaced during operation of the appliance without loss of access to the storage devices by the computers. In one embodiment, the server executes storage application software, such as backup software for backing up data on the storage devices, such as to a tape device networked to the server.

Abstract: A storage system includes two RAID controllers, each having two SAS initiators coupled to a zoning SAS expander. The expanders are linked by an inter-controller link and create a SAS ZPSDS. The expanders have PHY-to-zone mappings and zone permissions to create two distinct SAS domains such that one initiator of each RAID controller is in one domain and the other initiator is in the other domain. The disk drives are dual-ported, and each port of each drive is in a different domain. Each initiator can access every drive in the system, half directly through the local expander and half indirectly through the other RAID controller's expander via the inter-controller link. Thus, a RAID controller can continue to access a drive via the remote path in the remote domain if the drive becomes inaccessible via the local path in the local domain.

Abstract: A write-caching RAID controller includes a CPU that manages transfers of posted-write data from host computers to a volatile memory and transfers of the posted-write data from the volatile memory to a redundant array of storage devices when a main power source is supplying power to the RAID controller. A memory controller transfers the posted-write data received from the host computers to the volatile memory and transfers the posted-write data from the volatile memory for transfer to the redundant array of storage devices as managed by the CPU. The memory controller flushes the posted-write data from the volatile memory to the non-volatile memory when main power fails, during which time capacitors provide power to the memory controller, volatile memory, and non-volatile memory, but not to the CPU, in order to reduce the energy storage requirements of the capacitors.

Abstract: A network storage appliance is disclosed. The appliance includes a chassis enclosing a backplane, and a server enclosed in the chassis and coupled to the backplane. The appliance also includes storage controllers enclosed in the chassis, each coupled to the backplane, which control transfer of data between the server and storage devices coupled to the storage controllers. The storage controllers also control transfer of data between the storage devices and computers networked to the appliance and external to the appliance. The storage controllers and the server comprise a plurality of hot-replaceable blades. Any one of the plurality of blades may be replaced during operation of the appliance without loss of access to the storage devices by the computers. In one embodiment, the server executes storage application software, such as backup software for backing up data on the storage devices, such as to a tape device networked to the server.

Abstract: A network storage appliance is disclosed. The storage appliance includes a port combiner that provides data communication between at least first, second, and third I/O ports; a storage controller that controls storage devices and includes the first I/O port; a server having the second I/O port; and an I/O connector for networking the third I/O port to the port combiner. A single chassis encloses the port combiner, storage controller, and server, and the I/O connector is affixed on the storage appliance. The third I/O port is external to the chassis and is not enclosed therein. In various embodiments, the port combiner comprises a FiberChannel hub comprising a series of loop resiliency circuits, or a FiberChannel, Ethernet, or Infiniband switch. In one embodiment, the port combiner, I/O ports, and server are all comprised in a single blade module for plugging into a backplane of the chassis.

Abstract: A network storage appliance is disclosed. The storage appliance includes a port combiner that provides data communication between at least first, second, and third I/O ports; a storage controller that controls storage devices and includes the first I/O port; a server having the second I/O port; and an I/O connector for networking the third I/O port to the port combiner. A single chassis encloses the port combiner, storage controller, and server, and the I/O connector is affixed on the storage appliance. The third I/O port is external to the chassis and is not enclosed therein. In various embodiments, the port combiner comprises a FibreChannel hub comprising a series of loop resiliency circuits, or a FibreChannel, Ethernet, or Infiniband switch. In one embodiment, the port combiner, I/O ports, and server are all comprised in a single blade module for plugging into a backplane of the chassis.

Abstract: A storage controller has a capacitor pack for storing energy to supply power during a main power loss, a temperature sensor that senses the capacitor pack temperature, and a CPU, which detects that the temperature of the capacitor pack has risen above a predetermined threshold while operating at a first voltage value and determines whether a projected lifetime of the capacitor pack is less than the warranted lifetime. If the projected lifetime is less than the warranted lifetime, the CPU reduces the operating voltage of the capacitor pack to a second value, in order to increase the capacitor pack lifetime. In one embodiment, the CPU reduces the voltage if an accumulated normalized running time of the capacitor pack is greater than an accumulated calendar running time. In another embodiment, the CPU reduces the voltage if a percentage capacitance drop of the capacitor pack is greater than a calendar percentage capacitance drop.

Abstract: A network storage appliance is disclosed. The appliance includes a chassis enclosing a backplane, and a server enclosed in the chassis and coupled to the backplane. The appliance also includes storage controllers enclosed in the chassis, each coupled to the backplane, which control transfer of data between the server and storage devices coupled to the storage controllers. The storage controllers also control transfer of data between the storage devices and computers networked to the appliance and external to the appliance. The storage controllers and the server comprise a plurality of hot-replaceable blades. Any one of the plurality of blades may be replaced during operation of the appliance without loss of access to the storage devices by the computers. In one embodiment, the server executes storage application software, such as backup software for backing up data on the storage devices, such as to a tape device networked to the server.

Abstract: A network storage appliance including one or more integrated switching devices is disclosed. The appliance includes redundant storage controllers that transfer frames of data between storage devices and host computers. The integrated switching devices include a plurality of I/O ports and a data transfer path between each of the I/O ports for providing simultaneous data transfers between multiple pairs thereof. The switches enable the appliance to simultaneously transfer frames between its I/O ports and storage device I/O ports and/or host I/O ports, thereby providing increased data transfer bandwidth over arbitrated loop configurations. Additionally, the switches are intelligent and may be programmed to achieve improved fault isolation. The appliance may also include servers that include I/O ports coupled to the switches for simultaneously transferring data with the storage controllers and/or I/O ports of devices external to the appliance.

Abstract: A method for adopting an orphaned I/O port of a storage controller is disclosed. The storage controller has first and second redundant field-replaceable units (FRU) for processing I/O requests and a third FRU having at least one I/O port for receiving the I/O requests from host computers coupled to it. Initially the first FRU processes the I/O requests received by the I/O port and the third FRU routes to the first FRU interrupt requests generated by the I/O port in response to receiving the I/O requests. Subsequently, the second FRU determines that the first FRU has failed and is no longer processing I/O requests received by the I/O port, and configures the third FRU to route the interrupt requests from the I/O port to the second FRU rather than the first FRU, in response to the determining that the first FRU has failed.

Abstract: A write-caching RAID controller is disclosed. The controller includes a CPU that manages transfers of posted-write data from host computers to a volatile memory and transfers of the posted-write data from the volatile memory to storage devices when a main power source is supplying power to the RAID controller. A memory controller flushes the posted-write data from the volatile memory to the non-volatile memory when main power fails, during which time capacitors provide power to the memory controller, volatile memory, and non-volatile memory, but not to the CPU, in order to reduce the energy storage requirements of the capacitors. During main power provision, the CPU programs the memory controller with information needed to perform the flush operation, such as the location and size of the posted-write data in the volatile memory and various flush operation characteristics.

Abstract: A storage system includes two RAID controllers, each having two SAS initiators coupled to a zoning SAS expander. The expanders are linked by an inter-controller link and create a SAS ZPSDS. The expanders have PHY-to-zone mappings and zone permissions to create two distinct SAS domains such that one initiator of each RAID controller is in one domain and the other initiator is in the other domain. The disk drives are dual-ported, and each port of each drive is in a different domain. Each initiator can access every drive in the system, half directly through the local expander and half indirectly through the other RAID controller's expander via the inter-controller link. Thus, a RAID controller can continue to access a drive via the remote path in the remote domain if the drive becomes inaccessible via the local path in the local domain.

Abstract: A storage controller has a capacitor pack for storing energy to supply during a main power loss, a temperature sensor that senses the capacitor pack temperature, and a CPU, which repeatedly: receives the temperature during an interval over which the capacitor pack is operated, determines a lifetime over which the capacitor pack would have a capacity to store at least a predetermined amount of energy if operated at the temperature during the lifetime, normalizes the interval by a ratio of a warranted lifetime of the capacitor pack relative to the determined lifetime, and adds the normalized interval to an accumulated normalized running time. The operating voltage of the capacitor pack may also sampled and used to determine the lifetime. The predetermined amount of energy may be for backing up a volatile write cache to a non-volatile memory in response to the loss of main power.

Abstract: A method for transferring data within a network storage appliance is disclosed. The method includes transmitting a packet on an I/O link from a server to a first portion of a storage controller. Transmitting the packet on the I/O link is performed within a single blade module in a chassis enclosing the storage appliance. The method also includes forwarding a data transfer command within the packet from the first portion of the storage controller to a second portion of the storage controller. Forwarding the data transfer command is performed via a local bus on a backplane of the chassis through a connector of the blade connecting the blade to the backplane.

Abstract: A server blade includes a printed circuit board (PCB), including a connector for connecting the blade to a backplane comprising a local bus, and a removal mechanism for use by a person to disconnect the connector from the backplane for removal of the blade from a chassis while the chassis is powered up. The server blade also includes an I/O link and a server, each affixed on the PCB. The server transmits packets on the I/O link to a storage controller enclosed in the chassis. The packets include commands to transfer data to at least one storage device controlled by the storage controller. A portion of the storage controller, affixed on the PCB, receives the packets from the server on the I/O link, and forwards the commands on the backplane local bus to another portion of the storage controller affixed on a separate PCB enclosed in the chassis.

Abstract: A high data availability write-caching storage controller has a volatile memory with a write cache for caching write cache data, a non-volatile memory, a capacitor pack for supplying power for backing up the write cache to the non-volatile memory in response to a loss of main power, and a CPU that determines whether reducing an operating voltage of the capacitor pack to a new value would cause the capacitor pack to be storing less energy than required for backing up the current size write cache to the non-volatile memory. If so, the CPU reduces the size of the write cache prior to reducing the operating voltage. The CPU estimates the capacity of the capacitor pack to store the required energy based on a history of operational temperature and voltage readings of the capacitor pack, such as on an accumulated normalized running time and warranted lifetime of the capacitor pack.

Abstract: A network storage controller for transferring data between a host computer and a storage device, such as a redundant array of inexpensive disks (RAID), is disclosed. The network storage controller includes at least one channel interface module which is adapted to be connected to the host computer and storage device. The channel interface module is connected to a passive backplane, and selectively transfers data between the host computer and storage device and the passive backplane. The network storage controller also includes at least one controller memory module, attached to the passive backplane. The controller memory module communicates with the channel interface module via the passive backplane, and processes and temporarily stores data received from the host computer or storage device. In applications where redundancy is required, at least two controller memory modules and at least two channel interface modules are used.