Raid, short for Redundant Array of Independent Disks, is a method of storing data on hard drives for faster retrieval and redundancy.
RAID storage can be implemented on either a hardware or software level; the option you choose depends on your budget.
What Is raid storage
What Is RAID storage?
RAID storage (Redundant Array of Independent Disks) is a technology used for redundant data storage.
In its simplest form, it’s composed of multiple hard disks that store the same data, but the system can detect if one of the hard disks has failed and replace it with a duplicate.
RAID storage uses multiple physical disk drives and combines them into one logical unit.
In this case, you have a single volume for all your files, but the files are distributed across all the physical drives. This is done automatically by the operating system based on special rules called algorithms.
The benefit of this approach is that you can use all available disk space as a single volume and don’t need to worry about how much space each disk has left or if one disk failed – it won’t affect your data because it’s spread across different disks.
What Is Raid Storage?
When a raid storage array is configured as JBOD (Just A Bunch Of Disks), it’s called “disk in/out.”
This configuration, which uses a controller to select what disk gets used at any time, is not recommended because of the potential for undetected data corruption.
When RAID is set up as “disk in/out,” the failure of one drive in the array causes another drive to take over using its copy of the data.
In this scenario, if a second drive fails before the first one is replaced or repaired, you won’t know about it—the RAID controller will have assumed that both drives are good.
Raid arrays can be set up in one of two ways:
Level 0 (Striping)
A striped raid array stripes data across all disks in the array. It offers no redundancy and isn’t considered raid storage by people who use raid storage systems professionally.
Level 1 (Mirroring)
A mirrored raid array defeats an individual disk by mirroring everything on.
How to Calculate Drive Capacity
This site provides step-by-step instructions for how to calculate storage capacity based on the type of drive you are using. It is fairly technical but has lots of pictures and is easy to follow once you know the terminology.
How Solid State Drives Work
This article explains how an SSD (Solid-State Drive) works, including an explanation of how data is stored on an SSD drive as opposed to an HDD (Hard Disk Drive). This article also includes an overview of several types of SSDs and their uses.
RAID storage is a method of storing data on multiple hard drives, ideally of the same size and speed. RAID 0 uses striping, which involves splitting files into chunks that are distributed evenly across all disks.
Striping creates data redundancy by writing the same data to multiple hard drives at the same time.
If one drive fails, the others have identical copies of the data, so no information is lost.
Striping can also increase performance when reading and writing information because the data is spread across multiple disks.
The downside is that it uses more disks than mirroring or parity, which means it costs more money to set up and maintain, while offering less protection against disk failure.
Raid (Redundant Array Of Independent Disks)
There are two types of raid: software raid and hardware raid. Hardware raid is a physical array of drives while software raid is an assembly of virtual drives emulated by the operating system. Both have their strengths and weaknesses.
Hardware Raid
There are three levels of hardware raid: 0, 1, and 5. These stand for striping, mirroring, and parity respectively. The number represents the minimum number of drives in the array you need to create an n drive-sized array.
For example, a five drive RAID5 array needs at least five drives; a four drive RAID5 array needs at least six drives (four for data, two for parity) and so on. *The number of actual drives is not always equal to the number of data drives because a parity drive is used as well.
The parity drive holds the parity information that allows you to reconstruct data if there’s a failure in the array.
Striped Arrays
A striped array is one that stores data across all of the drives in the array (RAID0). This can improve performance for read operations because all data can be accessed simultaneously from multiple disks.
However, any write operation must be done sequentially across all disks (one after another) which decreases performance during write.
How Raid Redundancy Is Achieved
RAID stands for Redundant Array of Independent Disks. It’s a system that combines multiple disks into a single logical volume to increase performance and/or reliability.
The redundancy of RAID systems is achieved by mirroring the data across multiple drives, so if one fails, the other can take over. RAID 1 provides data redundancy by mirroring (duplicating) all the data on two or more drives, providing protection against drive failure.
The operating system is split between the two drives and reads and writes data from both simultaneously. If one drive fails, the other drive still contains all the data and can continue to operate as though nothing had happened.
When a failed drive is replaced, the data on it is re-created using information from the working drive. RAID 1 requires a minimum of two drives to implement and provides no additional performance gain over using a single drive.
RAID 0 (aka striping) distributes identical blocks of data across multiple drives, providing increased performance through parallel access to multiple disks, but at the cost of total data redundancy (drive failure will result in total loss of all data).
RAID 0 requires a minimum of two drives and can be created using any combination of hard disk sizes within reason.
Common Raid (Redundant Array Of Independent Disks) Configurations
If you are looking to understand raid, you will have come across some terms that may seem a little confusing. I will explain the most common raid configurations, what they mean and when to use them.
Raid level 1 is a single drive mirrored using a hardware controller. It is commonly referred to as a software raid since it doesn’t require any special hardware on the drive itself but does require at least two hard drives.
The biggest drawback to this configuration is that it requires twice the amount of storage capacity than you need. For example, if you set up a raid 1 array with 2 x 1TB drives, then the array will require 2 x 1TB drives’ worth of capacity in order for it to work.
One huge benefit of raid 1 is its fault tolerance. If any one drive fails, then it can be automatically rebuilt from the remaining drive in a matter of seconds or minutes depending on the size of the array and other factors.
This means that should one of your hard drives fail, then your data will still be safe and all you need to do is replace the failed drive and wait for it to rebuild itself.
Raid level 2 (commonly referred to as raid 10) distributes data evenly across multiple hard drives, providing large amounts of redundancy.
Less Common Raid (Redundant Array Of Independent Disks) Configurations
If you’ve ever read about raid (Redundant Array Of Independent Disks), you’ve probably heard of these “levels” before, but most people haven’t used them. Perhaps because they are less common than the others, but more likely because they are not supported on all Hardware.
Now, let’s look at each type of raid array and when you would want to use them:
Single RAID-0: This is a single disk with data striped across it. It has no redundancy and is really only useful on a server that is dedicated to a specific task, like video editing or file serving (where the server will be backed up anyway).
RAID-0+1: This setup is two disks mirrored together in a striped configuration. This provides some performance benefits over mirroring two drives together since there is no parity information written to the drives.
The downside is that if either drive fails, you lose all your data on both drives.
RAID-1+0 (or RAID-10): This setup is two mirrored disks striped together. Performance of this configuration is similar to mirroring two drives together, however, you have the added fault tolerance of having two copies of your data in case one drive fails.
Raid Storage To Safeguard Your Project
If you’re like many people, you probably have files and documents that you want to keep safe in the event of a computer crash or hard drive failure.
You can use an external drive, but there are other ways to safeguard your information — including raid storage, which stores data across multiple drives.
Tutorial:
Raid storage is designed to protect critical data by dividing information up among multiple drives.
It’s important to note that raid storage won’t guarantee your files will be safe if your computer crashes — it’s meant more as a way to prevent loss of data due to mechanical failure.
Why Should I Set Up A Raid Array?
In computing, a raid array is a group of hard drives that have been combined together to provide a single volume of storage space.
Though most common in the enterprise world, several software applications are available to help you create raid arrays on your home computer. Why would you make an array?
The most important reason is redundancy. If one drive in the array fails, the other drives can step in and provide the data you need without any loss of information.
The array will become unavailable until the failed drive is replaced, but your data will remain safe and undamaged.
Though redundant drive arrays can be found in enterprise settings, they’re also designed for home use.
Home users can set up redundant arrays to store important documents or family photos or even a media server that provides shared access to movies and music on all the computers on a network.
Before setting up a raid array, make sure you have enough hard drives to meet your needs. You’ll need at least two drives, but some software will allow for more than two levels of redundancy.
RAID (Redundant Array Of Independent Disks) Is No Substitute For Back-Ups!
In business, you never want to make excuses for your mistakes. Only after careful evaluation can you then begin to devise ways to prevent them from happening in the future.
Here’s one mistake that has cost several companies dearly: failing to implement a reliable backup … solution.
The RAID (Redundant Array of Independent Disks) was designed by a group of engineers at the University of California at Berkeley with the goal of providing an inexpensive and reliable method for backing up data.
RAID is based on the concept of spreading data across multiple disk drives for protection against drive failure.
Unfortunately, this is not a substitute for backing up your critical data files. Here are some of the problems with relying solely on RAID as a backup method:
- There is no way to recover your data if a second drive fails on a RAID array; RAID will continue to be operational but you will have lost all of your data.
- Another potential problem with using only RAID is that it creates “hot spots” on the disks where all of the read/write operations are being handled by one or two disks; this can lead to premature failure of those disks.
- Another point worth considering is that RAID arrays do nothing to protect against corrupted files, accidental deletion or destructive virus attacks.
