Edit Please don't do this!
In their June paper "A Case for Redundant Arrays of Inexpensive Disks RAID ", presented at the SIGMOD conference, they argued that the top performing mainframe disk drives of the time could be beaten on performance by an array of the inexpensive drives that had been developed for the growing personal computer market.
Although failures would rise in proportion to the number of drives, by configuring for redundancy, the reliability of an array could far exceed that of any large single drive. For example, a fast SSD can be mirrored with a mechanical drive. For this configuration to provide a significant speed advantage an appropriate controller is needed that uses the fast SSD for all read operations.
Adaptec calls this "hybrid RAID". These are called levels. Originally, there were five RAID levels, but many variations have evolved, notably several nested levels and many non-standard levels mostly proprietary.
A broken spanned volume at least preserves the files on the unfailing disks. Data is written identically to two drives, thereby producing a "mirrored set" of drives. Thus, any read request can be serviced by any drive in the set. If a request is broadcast to every drive in the set, it can be serviced by the drive that accesses the data first depending on its seek time and rotational latencyimproving performance.
Write throughput is always slower because every drive must be updated, and the slowest drive limits the write performance.
The array continues to operate as long as at least one drive is functioning. All disk spindle rotation is synchronized and data is striped such that each sequential bit is on a different drive. Hamming-code parity is calculated across corresponding bits and stored on at least one parity drive.
All disk spindle rotation is synchronized and data is striped such that each sequential byte is on a different drive.
Parity is calculated across corresponding bytes and stored on a dedicated parity drive. Upon failure of a single drive, subsequent reads can be calculated from the distributed parity such that no data is lost. Double parity provides fault tolerance up to two failed drives. This makes larger RAID groups more practical, especially for high-availability systems, as large-capacity drives take longer to restore.
The elements of a RAID may be either individual drives or arrays themselves. Arrays are rarely nested more than one level deep. If a single drive failure occurs then one of the stripes has failed, at this point it is running effectively as RAID 0 with no redundancy.
The array can sustain multiple drive losses so long as no mirror loses all its drives. Besides a drastic speed increase, this also provides a substantial advantage: Non-standard RAID levels Many configurations other than the basic numbered RAID levels are possible, and many companies, organizations, and groups have created their own non-standard configurations, in many cases designed to meet the specialized needs of a small niche group.
Such configurations include the following: Implementations[ edit ] The distribution of data across multiple drives can be managed either by dedicated computer hardware or by software. A software solution may be part of the operating system, part of the firmware and drivers supplied with a standard drive controller so-called "hardware-assisted software RAID"or it may reside entirely within the hardware RAID controller.
Software RAID can be implemented as: A layer that abstracts multiple devices, thereby providing a single virtual device e. Linux kernel 's md and OpenBSD's softraid A more generic logical volume manager provided with most server-class operating systems, e. Veritas or LVM A component of the file system e.In C, like normal data pointers (int *, char *, etc), we can have pointers to functions.
Following is a simple example that shows declaration and function call using function pointer. Matrix addition in C: C program to add two matrices, i.e., compute the sum of two matrices and then print it. Firstly a user will be asked to enter the order of matrix (number of rows and columns) and then two matrices.
This FPGA project is aimed to show in details how to process an image using Verilog from reading an input bitmap image .bmp) in Verilog, processing and writing the processed result to an output bitmap image in Verilog.
The full Verilog code for reading image, image processing, and writing image is provided. C Program to evaluate Subtraction of two matrices (matrix) in C C program to calculate sum of Upper Triangular Elements in C C Program to find addition of Lower Triangular Elements in C Programming.
More specifically, the GPU is especially well-suited to address problems that can be expressed as data-parallel computations - the same program is executed on many data elements in parallel - with high arithmetic intensity - the ratio of arithmetic operations to memory operations. Matrix addition in C: C program to add two matrices, i.e., compute the sum of two matrices and then print it.
Firstly a user will be asked to enter the order of matrix (number of .