RAID 0, RAID 1, RAID 5, RAID 10 Explained with Diagrams

PowerPoint Presentation: 

RAID ( R edundant A rray of I ndependent D isks ) By A.Sai Bala Subrahmanyam MCA A.sai bala subrahmanyam

PowerPoint Presentation: 

What is RAID? RAID (redundant array of independent disks, originally redundant array of inexpensive disks ) is a way of storing the same data in different places (thus, redundantly) on multiple hard disk s. Placing data on multiple disks, I/O (input/output) operations can overlap in a balanced. improving performance. Since multiple disks increases the mean time between failures ( MTBF ) storing data redundantly also increases fault tolerance . Capacity is calculated by Number of Drives x Capacity of Disk = Capacity of Array A.sai bala subrahmanyam

PowerPoint Presentation: 

There are at least nine types of RAID plus a non-redundant array (RAID-0): RAID-0: This technique has striping but no redundancy of data. It offers the best performance but no fault-tolerance. Advantages Read/Write performance inscreased by spreading the load acrros many channels adn drives No parity calculation overhead is involved Very simple design Disadvantages Not "TRUE" RAID, because there is no fault tolerance The failure of just one drive will result in all data in an array being lost After a certain amount of drives, performance does not increase significatly. Requirements RAID Level 0 requires a minimum of 2 drives to implement. A.sai bala subrahmanyam

PowerPoint Presentation: 

Applications Any application which requires very high speed storage, but does not need redundancy. Video Production and Editing Image Editing Pre-Press Applications Any application requiring high bandwidth Video Production and Editing Image Editing Pre-Press Applications Any application requiring high bandwidth A.sai bala subrahmanyam

PowerPoint Presentation: 

There are at least nine types of RAID plus a non-redundant array (RAID-1): RAID-1: This type is also known as disk mirroring and consists of at least two drives that duplicate the storage of data. There is no striping. Read performance is improved since either disk can be read at the same time. Write performance is the same as for single disk storage. RAID-1 provides the best performance and the best fault-tolerance in a multi-user system. (2 x Capacity of Disk) - Capacity of Disk = Capacity of Array or simply Capacity of Disk = Capacity of Array A.sai bala subrahmanyam

PowerPoint Presentation: 

Advantages RAID 1 offers excellent read speed and a write-speed that is comparable to that of a single disk. In case a disk fails, data do not have to be rebuild, they just have to be copied to the replacement disk. RAID 1 is a very simple technology. Disadvantages The main disadvantage is that the effective storage capacity is only half of the total disk capacity because all data get written twice. Software RAID 1 solutions do not always allow a hot swap of a failed disk (meaning it cannot be replaced while the server keeps running). Ideally a hardware controller is used. Ideal use RAID-1 is ideal for mission critical storage, for instance for accounting systems. It is also suitable for small servers in which only two disks will be used. A.sai bala subrahmanyam

PowerPoint Presentation: 

RAID-2: This type uses striping across disks with some disks storing error checking and correcting ( ECC ) information. It has no advantage over RAID-3. There are at least nine types of RAID plus a non-redundant array (RAID-2): A.sai bala subrahmanyam

PowerPoint Presentation: 

RAID-3: This type uses striping and dedicates one drive to storing parity information. The embedded error checking (ECC) information is used to detect errors. Data recovery is accomplished by calculating the exclusive OR (XOR) of the information recorded on the other drives. Since an I/O operation addresses all drives at the same time, RAID-3 cannot overlap I/O. For this reason, RAID-3 is best for single-user systems with long record applications. There are at least nine types of RAID plus a non-redundant array (RAID-3): Advantages RAID-3 provides high throughput (both read and write) for large data transfers. Disk failures do not significantly slow down throughput. Disadvantages This technology is fairly complex and too resource intensive to be done in software. Performance is slower for random, small I/O operations. Ideal use RAID 3 is not that common in prepress. A.sai bala subrahmanyam

PowerPoint Presentation: 

RAID-4: This type uses large stripes, which means you can read records from any single drive. This allows you to take advantage of overlapped I/O for read operations. Since all write operations have to update the parity drive, no I/O overlapping is possible. RAID-4 offers no advantage over RAID-5. There are at least nine types of RAID plus a non-redundant array (RAID-4): A.sai bala subrahmanyam

PowerPoint Presentation: 

RAID-5: This type includes a rotating parity array, thus addressing the write limitation in RAID-4. Thus, all read and write operations can be overlapped. RAID-5 stores parity information but not redundant data (but parity information can be used to reconstruct data). RAID-5 requires at least three and usually five disks for the array. It's best for multi-user systems in which performance is not critical or which do few write operations. There are at least nine types of RAID plus a non-redundant array (RAID-5): Advantages Read data transactions are very fast while write data transaction are somewhat slower (due to the parity that has to be calculated). Disadvantages Disk failures have an effect on throughput, although this is still acceptable. Like RAID 3, this is complex technology. Ideal use RAID 5 is a good all-round system that combines efficient storage with excellent security and decent performance. It is ideal for file and application servers. A.sai bala subrahmanyam

PowerPoint Presentation: 

RAID-6: This type is similar to RAID-5 but includes a second parity scheme that is distributed across different drives and thus offers extremely high fault- and drive-failure tolerance. There are at least nine types of RAID plus a non-redundant array (RAID-6): A.sai bala subrahmanyam

PowerPoint Presentation: 

RAID-7: This type includes a real-time embedded operating system as a controller, caching via a high-speed bus, and other characteristics of a stand-alone computer. One vendor offers this system. There are at least nine types of RAID plus a non-redundant array (RAID-7): A.sai bala subrahmanyam

PowerPoint Presentation: 

RAID-10: Combining RAID-0 and RAID-1 is often referred to as RAID-10, which offers higher performance than RAID-1 but at much higher cost. There are two subtypes: In RAID-0+1, data is organized as stripes across multiple disks, and then the striped disk sets are mirrored. In RAID-1+0, the data is mirrored and the mirrors are striped. There are at least nine types of RAID plus a non-redundant array (RAID-10): RAID is no substitute for back-up! All RAID levels except RAID 0 offer protection from a single drive failure. A RAID 6 system even survives 2 disks dying simultaneously. For complete security you do still need to back-up the data from a RAID system. That back-up will come in handy if all drives fail simultaneously because of a power spike. It is a safeguard if the storage system gets stolen. Back-ups can be kept off-site at a different location. This can come in handy if a natural disaster or fire destroys your workplace. The most important reason to back-up multiple generations of data is user error. If someone accidentally deletes some important data and this goes unnoticed for several hours, days or weeks, a good set of back-ups ensure you can still retrieve those files. A.sai bala subrahmanyam

PowerPoint Presentation: 

There are at least nine types of RAID plus a non-redundant array (RAID-50): RAID-50 (or RAID-5+0): This type consists of a series of RAID-5 groups and striped in RAID-0 fashion to improve RAID-5 performance without reducing data protection. A.sai bala subrahmanyam

PowerPoint Presentation: 

There are at least nine types of RAID plus a non-redundant array (RAID-53): RAID-53 (or RAID-5+3): This type uses striping (in RAID-0 style) for RAID-3's virtual disk blocks. This offers higher performance than RAID-3 but at much higher cost. A.sai bala subrahmanyam

PowerPoint Presentation: 

There are at least nine types of RAID plus a non-redundant array (RAID-s): RAID-S (also known as Parity RAID): This is an alternate, proprietary method for striped parity RAID from EMC Symmetrix that is no longer in use on current equipment. It appears to be similar to RAID-5 with some performance enhancements as well as the enhancements that come from having a high-speed disk cache on the disk array A.sai bala subrahmanyam

PowerPoint Presentation: 

A.sai bala subrahmanyam Let us be grateful to people who make us happy; they are the charming gardeners who make our souls blossom.