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RAID Comparison | Which Is the Fastest RAID Level
When building a server, you may want to choose a fastest RAID array. So which RAID level is the fastest? This article will answer that question.
By Crystal / Updated on December 2, 2022
Case: What is the fastest RAID level in practice?
I'm going to be rebuilding my server, and I want much faster access to my data. Assuming the Hardware RAID Card supports each level, what is currently the FASTEST RAID available, given x number of hard drives? Reliability is now another factor, and I am willing to spend money on new drives if a drive (or multiple) fail. I simply want to know what the fastest RAID level is, along with some reliability for recovering from a failure.
- Question from superuser.com
RAID is a technology that is used to increase the performance and reliability of data storage, some allows disaster recovery. When build a server, you may be trouble about how to choose the right RAID level for your storage array, as in the case above.
When choosing a RAID level for your storage array, it’s important to consider what you need most: speed, or fault tolerance. You may want to know what is the fastest RAID level? This article will briefly introduce 5 common RAID types, and make a comparison to show which one is the fastest RAID type.
What is RAID
The acronym "RAID" was coined in 1988 by UC Berkeley computer scientists David Patterson, Garth Gibson, and Randy Katz in their research paper on data management, "The Case for RAID". Its full name is Redundant Array of Independent Disks, a storage technology that creates a data loss fail-safe by merging two or more hard disk drives (HDDs) or solid-state drives (SSDs) into one cohesive storage unit, or array.
RAID storage protects against the total loss of a disk drive’s data by repeating or recreating that data and storing it on the additional drive or drives, a process also known as data redundancy. Configurations that offer data loss protection are referred to as “fault-tolerant.” This just means that the array will continue to function successfully and provide recoverable data in the event of a disk drive failure.
The 5 most common RAID types
Standardized by the Storage Networking Industry Association (SNIA), there are many RAID levels in use today, and RAID configurations are typically evaluated based on their level of fault tolerance, read and write speeds, and storage capacity.
The most common RAID configurations are RAID 0, RAID 1, RAID 5, RAID 6, and RAID 10. Next, I will briefly introduce them in this part.
RAID 0
RAID 0 is the simplest RAID storage design. It works by using data striping, a process that separates system data blocks into segments and stores across several different disks. This allows the server to leverage the speed of multiple disks, meaning that in theory, the more disks you add to the array, the faster the array will become.
RAID 0 is by far the fastest RAID type. However, it is also the only RAID type without fault tolerance. If one drive fails, all data in the RAID 0 array are lost. It should not be used for mission-critical systems.
RAID 1
RAID 1 works by using disk mirroring to duplicate your data between two disks for storage. If one of the drives fail, all the data can be read from the other drive. Therefore, at least 2 drives are needed for a RAID 1 array, and sometimes a third disk that is used as a hot spare, in order to prevent downtime in the event of a disk failure.
RAID 1 offers excellent read speed and a write-speed that is comparable to that of a single drive, is ideal for mission critical storage. However, it also has disadvantage that the effective storage capacity is only half of the total drive capacity, because all data get written twice.
RAID 5
RAID 5 is probably the most common RAID configuration. It utilizes a combination of data striping and parity to achieve fault tolerance with improved read speeds. It requires a minimum of 3 drives to implement. Each drive in the array sets aside a portion of itself for parity. In the event of a drive failure, the array will use the parity on the remaining drives to recover any data that was being stored on the failed drive.
RAID 5 is typically used on mission critical servers with some budget constraints, it combines efficient storage with excellent security and decent performance. However, drive failures can have effect on its throughput.
RAID 6
RAID 6 is also works by using data striping and parity for redundancy. But different from RAID 5, it includes 2 independent sets of separately striped parity data. That means it requires at least 4 drives, and can withstand 2 drives dying simultaneously.
A RAID 6 array can recover from two simultaneous disk failures, it means you are extra protected. However, the extra parity also slows down the performance.
RAID 10
RAID 10 works by joining multiple RAID 1 arrays together using RAID 0 striping. A minimum of 4 drives are required. And it is highly scalable, allowing you to add new RAID 1 mirrors to grow the RAID 10 array.
RAID 10 array can withstand multiple drive failures, provides increased security while still having excellent speed due to the RAID 1 arrays being striped together. It is the RAID level of choice for enterprise operations requiring fault tolerance and high disk speeds.
Raid level comparison: Which RAID level is the fastest?
So, how do you choose from the different RAID types? And which raid level is the fastest? Here I provide you a clear comparison for you to make the right choice.
| RAID 0 | RAID 1 | RAID 5 | RAID 6 | RAID 10 | |
| Minimal disk number | 2 | 2 | 3 | 4 | 4 |
| Read speed | fast | fast | slow | slow | fast |
| Write speed | fast | fair | slow | slow | fair |
| Fault tolerance | none | 1 disk | 1 disk | 2 disks | 1 disk |
| Hardware cost | low | high | high | very high | high |
As you can see, RAID 0 is the fastest RAID level. If you think that read and write speed is your primary need, then you might consider RAID 0.
But RAID 0 is not fault tolerant. If you want to balance the storage performance, then RAID 5 may be a good choice, as it provides redundancy, allow maximum disk usage, and give you data protection that you can count on.
RAID cannot replace backups
Although all RAID levels except RAID 0 provide protection against individual drive failures, you still need to backup the data stored on your RAID system in order to protect them against natural disaster damage, theft of the storage system, and user misuse for complete data security.
If you want to protect the VMs running on your storage system, you can try free virtual machine backup software -- AOMEI Cyber Backup. It allows you to create complete and independent image-level VM backup for both paid and free versions of VMware ESXi and Hyper-V. And you can use AOMEI Cyber Backup Free Edition with no time limit.
*You can choose to install this VM backup software on either Windows or Linux system.
Summary
There are many RAID levels are being used today. To choose the right RAID type, you first need to determine your primary needs. If the most important thing for you is speed, then you may next find out which is the fastest RAID type.
This article introduced 5 most common RAID levels, and made a comparison to show which is the fastest RAID level. However, RAID cannot replace backup. For example, you still need to take virtual machine backup on your storage system to ensure the complete data security.
