Acronym for application-specific integrated circuit. A microchip that is designed for a specific application or purpose, such as a particular kind of transmission protocol. An ASIC can improve speed because it is designed to do one specific thing.
Acronym for Basic Input/Output System. Software that provides basic read/write capability. Usually kept as firmware (ROM-based). The system BIOS on the motherboard of a computer boots and controls the system. The BIOS on your host adapter acts as an extension of the system BIOS. See UEFI.
Refers to the way a computer is set up, the combined hardware components (computer, monitor, keyboard, and peripheral devices) that comprise a computer system, or the software settings that enable the hardware components to communicate with each other.
Abbreviation for double data rate. DDR is adavanced type of computer memory chip that can transfer data twice as fast as regular memory chips. This is because DDR memory can send and receive signals twice per clock cycle.
Abbreviation for double data rate 2 or 3. An improved version of DDR memory. See DDR.
A program that enables a microprocessor (through the operating system) to direct the operation of a peripheral device.
Acronym for Digital, Intel, and Xerox. An Ethernet standard, defined by these three companies (Digital, Intel, and Xerox), that specified 10 Mbit/s Ethernet, with 48-bit destination and source addresses and a global 16-bit Ethernet-type field.
A software procedure in which a host queries a device to determine its ability to communicate at the negotiated data rate.
A group of physical drives that combines the storage space on the drives into a single segment of storage space. A hot-spare drive does not actively participate in a drive group.
Abbreviation for Edison Engineering Development Program. A program, run by General Electric, that provides advanced courses in engineering and technical projects.
Acronym for electronically erasable programmable read-only memory. It is a memory chip that typically stores configuration information, as it provides stable storage for long periods without electricity and can be reprogrammed. See NVRAM.
A SAS device installed outside the computer chassis. These devices are connected using specific types of shielded cables.
Abbreviation for Fusion-Message Passing Technology architecture. Fusion-MPT consists of several main elements: Fusion-MPT firmware, the Fibre Channel and SCSI hardware, and the operating system-level drivers that support these architectures. Fusion-MPT architecture offers a single binary, operating system driver that supports both Fibre Channel and SCSI devices.
Abbreviation for host bus adapter. A piece of hardware that connects a host to network and storage devices.
The computer system in which a RAID adapter is installed. It uses the RAID adapter to transfer information to and from devices attached to the SCSI bus.
A circuit board or integrated circuit that provides a device connection to the computer system.
An idle, powered-on, standby drive that is ready for immediate use in case of drive failure. A hot spare does not contain any user data. A hot spare can be dedicated to a single redundant array or it can be part of the global hot spare pool for all arrays managed by the HBA.
When a drive fails, the HBA firmware automatically replaces and rebuilds the data from the failed drive to the hot spare. Data can be rebuilt only from virtual drives with redundancy (RAID levels 1, 5, 6, 10, 50, and 60; not RAID level 0), and the hot spare must have sufficient capacity.
A SAS device installed inside the computer cabinet. These devices are connected using a shielded cable. SeeSAS.
The part of computer memory that is directly accessible by the CPU, usually synonymous with RAM.
Acronym for nonvolatile random access memory. An EEPROM (electronically erasable read-only memory) chip that stores configuration information. See EEPROM.
Abbreviation for Peripheral Component Interconnect. A high-performance, local bus specification that enables the connection of devices directly to computer memory. The PCI Local Bus enables transparent upgrades from 32-bit data path at 33 MHz to 64-bit data path at 33 MHz, and from 32-bit data path at 66 MHz to 64-bit data path at 66 MHz.
Abbreviation for Peripheral Component Interconnect Express. A high-performance, local bus specification that enables the connection of devices directly to computer memory. PCI Express is a two-way, serial connection that transfers data on two pairs of point-to-point data lines. PCI Express goes beyond the PCI specification in that it is intended as a unifying I/O architecture for various systems: desktops, workstations, mobile, server, communications, and embedded devices.
A piece of hardware (such as a video monitor, drive, printer, or CD-ROM) used with a computer and under the control of the computer. SCSI peripherals are controlled through an Oracle Storage 12 Gb/s SAS PCIe RAID HBA, Internal (host bus adapter).
The interface required to transmit and receive data packets transferred across the serial bus.
Each PHY can form one side of the physical link in a connection with a PHY on a different SATA device. The physical link contains four wires that form two differential signal pairs. One differential pair transmits signals, while the other differential pair receives signals. Both differential pairs operate simultaneously and enable concurrent data transmission in both the receive and the transmit directions.
Acronym for Serial Attached SCSI. A serial, point-to-point, enterprise-level device interface that leverages the proven SCSI protocol set. The SAS interface provides improved performance, simplified cabling, smaller connections, lower pin count, and lower power requirements when compared to parallel SCSI. SAS host bus adapters leverage a common electrical and physical connection interface that is compatible with Serial ATA. Each port on the SAS RAID adapter supports SAS devices, SATA II devices, or both.
Any device that conforms to the SAS standard and is attached to the SAS bus by a SAS cable. This includes SAS RAID adapters (host adapters) and SAS peripherals.
Acronym for Serial Advanced Technology Attachment. A physical storage interface standard, SATA is a serial link that provides point-to-point connections between devices. The thinner serial cables enable better airflow within the system and permit smaller chassis designs.
Acronym for Synchronous Dynamic Random Access Memory. SDRAM is dynamic random access memory (DRAM) that is synchronized with the system bus.
Acronym for Small Form Factor. Any of several physically compact connector designs used in fiber optic systems.
Acronym for Serial Management Protocol. SMP communicates topology management information directly with an attached SAS expander device. Each PHY on the adapter can function as an SMP initiator.
A method for combining multiple drives into a single logical drive. If you want to have all of the drive capacity in one drive group, you can span (merge) the drives so that the operating system sees just one large drive. For more information, refer to the MegaRAID SAS Software User's Guide, located at: https://www.broadcom.com/support/oem/oracle/.
Abbreviation for Serial SCSI Protocol. SSP enables communication with other SAS devices. Each PHY on the SAS adapter can function as an SSP initiator or SSP target.
Abbreviation for Serial Tunneling Protocol. STP enables communication with a SATA II device through an attached expander. Each PHY on the SAS adapter can function as an STP initiator. See SATA .
The total drive space consumed by a stripe not including a parity drive. For example, consider a stripe that contains 64 Kbytes of drive space and has 16 Kbytes of data residing on each drive in the stripe. In this case, the stripe size is 64 Kbytes and the stripe element size is 16 Kbytes. The stripe depth is four (four drives in the stripe). You can specify stripe sizes of 8 Kbytes, 16 Kbytes, 32 Kbytes, 64 Kbytes, 128 Kbytes, 256 Kbytes, 512 Kbytes, or 1 Mbyte for each logical drive. A larger stripe size produces improved read performance, especially if most of the reads are sequential. For mostly random reads, select a smaller stripe size.
Drive striping writes data across two or more drives. Each stripe spans two or more drives but consumes only a portion of each drive. Each drive, therefore, may have several stripes. The amount of space consumed by a stripe is the same on each drive that is included in the stripe. The portion of a stripe that resides on a single drive is a stripe element. Striping by itself does not provide data redundancy; striping in combination with parity provides data redundancy.
Abbreviation for Unified Extensible Firmware Interface. A standard programming interface used for booting a computer. UEFI is designed to replace BIOS (basic input/output system). See BIOS.
A storage unit created by a RAID controller from one or more drives. Although a virtual drive may be created from several drives, it is seen by the operating system as a single drive. Depending on the RAID level used, the virtual drive can retain redundant data in case of a drive failure.