RAID Recovery - InfiniBand
InfiniBand specification
The InfiniBand specification is a combination of two designs: Future I/O, developed by Compaq, IBM, and Hewlett-Packard and Next Generation I/O, developed by Intel, Microsoft, and Sun Microsystems. InfiniBand uses Internet Protocol Version 6 (IPv6).
InfiniBand is mostly used for performance focused computer cluster applications. InfiniBand adoption in TOP500 supercomputers is much [...]
RAID Recovery - Command-line interface
Command Line Interpreter
A command line interpreter implements the text interface between the user and the operating system. Examples of command line interpreters include UNIX shells (sh, ksh, csh, tcsh, bash, etc.), CP/M, and Command.com. Windows PowerShell version 1.0 was the first command line interpreter for Windows. It combines features of UNIX [...]
RAID Recovery - Western Digital
Important innovations
In 1998, WDC entered into an agreement with IBM to use certain IBM technologies including giant magneto-resistive (GMR) heads and access to IBM production facilities. The partnership produced the Expert line of drives in 1999. In 2000, WDC broke the ties with IBM.
In 2001, WDC offered mainstream ATA hard disk [...]
RAID Recovery - Time-Limited Error Recovery
TLER in Desktop Computers
TLER can be enabled or disabled on certain Western Digital drives by using a tool called WDTLER on a DOS bootdisk. In order to disable TLER, the read/write value is set to 0 seconds.
In Western Digital enterprise drives such as Raptor, Caviar RE2 and RE2-GP, the TLER [...]
RAID Recovery - Expansion card
Expansion slot standards
PCI Express (PCIe)
PCIe finds application in consumer, server and industrial PCs. It is used both as a motherboard-level interconnect and as an expansion card interface for add-in boards. PCIe, unlike its predecessors, uses point-to-point serial links. Previous versions of expansion cards used shared parallel bus architecture.
Other standards
Other common standards [...]
RAID Recovery - Downtime
Impact of downtime
Others are sensitive to the timing of the outage, i.e., they face more problems when the service is not available during critical hours of the day.
In service level agreements (SLAs), ISPs mention a certain percentage of allowable downtime per month. Downtime about 1 percent per year is considered unacceptable. For [...]
RAID Recovery - Cache
How it works?
Each entry has a tag, which gives a unique identify to the datum. For example, in a Web browser program, the URL is considered the tag, and the content of the Web page is the datum.
When a cache client, for example, a processor, Web browser or operating system, wants to [...]
RAID Recovery - Cyclic redundancy check
CRC Architecture
A CRC is simple to use and easy to analyze. The function is highly efficient than alternative methods such as multiple parity checks. If an n-bit CRC is applied to a data block of arbitrary length, it will detect the error burst not longer than n bits, and will [...]
RAID Recovery - Non-volatile random access memory
Modern Approaches to Non-Volatile Memory
Today, several new devices are being developed to address the volatility issues of the memory devices. The most popular among them is Ferroelectric RAM (FeRAM). FeRAM resembles the conventional DRAM, except that it uses a ferroelectric layer in its cell.
Magneto-resistive Random Access Memory (MRAM), another [...]
RAID Recovery - IBM 305 RAMAC
Architecture
RAMAC 305 system also consisted of punched card input/output, a central processing unit, a power supply unit, and a printer. It also had arithmetical and logical ability. Additionally there was a manual inquiry station that allowed direct access to stored records. RAMAC could also include additional features such as punched [...]
