Redundant Array of Independent Disks (RAID) is an advanced data storage virtualization technology, which is widely used by gamers, developers, video editors, professionals, and businesses around the world. That’s because RAID offers many advantages—such as data redundancy, higher read/write speeds, or both—over the traditional hard drive storage.
One can choose from several RAID levels starting with RAID 0 to RAID 10, which is a nested RAID arrangement of RAID 1 and RAID 0. Similarly, one can also create RAID 50, RAID 60, or RAID 100 as per their data storage requirements. However, nested RAID levels are expensive, and most users can’t afford it.
LaCie 2big RAID 4TB External Hard Drive Desktop HDD – USB-C USB 3.0 7200 RPM Enterprise Class Drives, for Mac and PC Desktop, Data Redundancy (STHJ4000800) 3.6 out of 5 stars 29 $354.00 $ 354. Browse the top-ranked list of Raid 5 Hard Drive below along with associated reviews and opinions. WD - Mainstream 1TB Internal Serial ATA Hard Drive for Desktops. The drive is designed for use with select PC and Mac desktops for storing a wealth of games, movies, music, pictures and more. Data transfer rates up to 6. The Best External Hard Drives and SSDs for Mac in 2020. Looking to add storage, or for a smart way to back up your Mac? Here's what you need to know, along with our top-rated Apple-friendly drives.
Also, always keep a backup of your data stored in your RAID drive to prevent permanent data loss. Please be aware; RAID is not a backup or alternative to backup. The purpose of RAID is to achieve high read/write performance for intensive tasks and maintain data availability in case of a drive failure. In case of loss of data use Stellar Data Recovery Technician software to get back your lost or deleted data.
Which One Should You Choose and Why?
To help you decide which RAID level is right for your data storage needs and, most importantly, budget, we have detailed everything about various RAID levels—from RAID 0 to RAID 60—and mentioned their advantages, drawbacks, and applications.
RAID Levels—A Detailed Comparison
Below is a detailed comparison of standard RAID levels such as RAID 0, RAID 1, RAID 5, RAID 6 and nested RAID levels--RAID 10, RAID 50, RAID 60. A comparison chart is also attached at the end of the post, comparing various RAID levels on parameters such as minimum drives requirement, read/write performance, storage availability, redundancy, and application.
RAID 0
If you are into gaming and video editing, RAID 0 is the right configuration for your data storage needs. RAID 0 is a standard RAID configuration, which uses striping method to store data on the disk array. It’s the most affordable RAID configuration that requires at least two disks.
Demanding tasks such as gaming and video editing requires frequent data transfer, often in large volumes. RAID 0 increases the read and writes performance of your system by up to 2X than the normal hard drive and spreads the load across drives.
Figure 1: RAID 0 Illustration- Striping Storage method is used for data storage
Pros
- High read/write performance, comparable to SATA SSDs
- 100% Disk volume available for use
- Affordable and easy to implement
Cons
- No fault-tolerance (redundancy)
Applications
- For storing and accessing non-critical data
- Gaming
- Video and Image Editing
Recovery Management
- If a drive fails in a RAID 0 level, data will be permanently lost as RAID 0 does not offer redundancy. However, you can recover a logically failed or broken RAID 0 level with the help of a RAID recovery software such as Stellar Data Recovery Technician.
RAID 1
RAID 1 uses mirroring method to for data storage and requires at least two drives. It’s the most basic RAID level that provides redundancy, i.e., protection against data loss due to disk failure. The data copied to RAID 1 is stored in both drives as individual copies. Thus, if one disk fails, you will be able to recover data from another drive.
Figure 2: RAID 1 Illustration- Mirroring Storage method is used for data storage
Due to mirroring, RAID 1 storage is halved, i.e., you can use 50% of total disk volume with normal read/write speeds. However, unlike RAID 0, RAID 1 can withstand up to 1 disk failure in each array without causing data loss.
Pros
- Offers read/write speeds equivalent to SATA III hard drive
- Fault-tolerant—can withstand up to 1 drive failure
- No overhead as data needs to be copied to a replacement drive, not rebuild
- Affordable and easy to implement
Cons
- 50% Storage space is available for usage
- Hot swap is a problem in many software-based RAID 1 array
Applications
Raid 5 Format
- For storing critical data such as accounting files
- For small servers
Recovery Management
- RAID 1 can rebuild itself as quick as 30 minutes to an hour as data is copied—not rebuild—from surviving drive to the new drive.
RAID 5
RAID 5 is expensive and often used by professionals and businesses. Unlike RAID 0 and RAID 1, RAID 5 requires a dedicated hardware controller with minimum 3 storage drives and supports maximum 16 disks. It uses striping and parity bit data storage method to store your files across the disk array.
It provides high read and write speeds along with redundancy due to parity bits. Parity bits are the checksum of all data stored in all drives of RAID 5 array.
A user can utilize up to 94% of the total combined disk volume.
The parity bit helps restore data lost due to failure of up to 1 disk in the array.
Figure 3: RAID 5- Mirroring With Parity Across Drives
Pros
- Read data transactions are fast due to faster read speed but write speed is a bit slower, yet decent, due to parity bit calculation
- Fault-tolerant—can withstand up to any 1 drive failure in the array
- Up to 94%, combined disk volume is available for use
Cons
- Overhead on all drive after disk failure and RAID rebuild
- RAID rebuild after disk failure can take several hours to a few days depending on the size of a failed disk
- Costly
Applications
- File and application servers
- Data warehousing
- Archiving
Recovery Management
- RAID 5 rebuild can take several hours and cause overhead, which can lead to another drive failure during, rebuild process. So before inserting new drive to RAID 5 array, check each disk’s SMART status by using a tool such as Drive Monitor, CrystalDiskInfo, etc.
- Use Stellar Data Recovery Technician to rebuild and recover data when RAID 5 gets damaged due to corruption or other logical errors.
RAID 6
RAID 6 is a better version of RAID 5 and is often referred as ‘RAID 5 on Steroids’. RAID 6 overcomes a major issue in the RAID 5, which is the inability to survive more than 1 disk failure. RAID 6 can withstand up to 2-disk failure without data loss.
RAID 6 also uses striping and parity bits to store data. However, unlike RAID 5, RAID 6 stores parity bits in two disks and thus requires minimum 4 disk in the array. And thus, offers balanced read/write speeds with better redundancy.
Due to two parity bits, RAID 6 allows you to utilize up to 88% of the combined disk storage volume.
Figure 4: RAID 6- Mirroring with DUAL-Parity across drives
Pros
- Fast read data transactions
- Fault-tolerant—can withstand up to any 2 disk failure from the array
- More secure than RAID 5
Cons
- Write data transactions are slower than RAID 5 due to dual-parity data
- Drive failure affects the entire RAID array
- Rebuilding RAID array can take a very long time
Applications
Raid 5 For Home Nas
- High availability solutions
- Archiving
- Large critical databases
Recovery Management
- Instead of rebuilding RAID 6 directly after a disk failure, take out other drives from the RAID array and check the SMART status of the individual drive with Drive Monitor utility to ensure disks are healthy enough to withstand the rebuild process. If SMART shows warning such as Reallocated Sector Count Warning, Pending Sector Count warning, etc. use Stellar Data Recovery Technician to rebuild RAID 5 and recover data—works if disk failure occurs due to logical errors
RAID 10
RAID 10 is the nested RAID configuration made from a combination of RAID 1 and RAID 0. It’s a mirrored RAID 0 level. It uses both data striping and data mirroring storage methods in a nested environment. Thus, it offers both higher read/write speeds and better data redundancy than RAID 5 and RAID 6.
It requires at least 4 disks, but the total storage is halved due to mirroring. So if you are going to use 4 1TB drives, you will essentially get 2TB usable storage. It can withstand up to 2 disk failure—one from either side. However, if two disks from one side fail, data will be lost and can’t be recovered.
Figure 5: RAID 10- Combination of RAID 1 (Mirroring) and RAID 0 (Striping) array
Pros
- Faster rebuild time as there is no parity data
- Faster read and write speeds
- Fault-tolerant—can withstand up to 2 disk failure from one side
Cons
- Only 50% of storage is available for use
- Most expensive RAID level compared to RAID 6 which can also withstand up to 2 disks failure
Applications
- Fast database servers
- Application servers
Recovery Management
- RAID 10 can rebuild quickly after a disk failure, as data is copied from the surviving drives to the new drive — similar to RAID 0. Also, there are quite fewer chances of failing two drives simultaneously from the same side. Thus, RAID 10 is self-sufficient in recovery.
- For recovery of corrupt and logically failed RAID 10 array, reach out to a data recovery expert.
RAID 50 & RAID 60
RAID 50 and RAID 60 are also nested RAID configurations of ‘RAID 5+RAID 0’ and ‘RAID 6+RAID 0’. Thus, it offers features of both RAID 5 and 6 along with RAID 0’s high read/write speed performance.
RAID 50 requires minimum 6 and supports maximum 48 disks in single or multiple mirrored arrays of RAID 5.
Similarly, RAID 60 requires at least 8 disk drives configured as two mirrored RAID 6 arrays
These RAID configurations are used for storing large databases, archives, backups, and as application servers. These RAID configurations offer high availability and can withstand up to 1 drive failure in each sub-array.
Figure 6: RAID Level comparison chart
You might be wondering where are RAID 2, RAID 3 and RAID 4. Well, they are not used anymore. And out of all RAID arrays, RAID 0, RAID 1, RAID 5 and RAID 6 are the most popular RAID levels used by various users ranging from a home user to a professional and businesses.
Conclusion
While choosing a RAID level, consider your needs—do you want performance, redundancy, or both. RAID 0 and 1 are suitable for home and some power users. They are easy to set up and does not always require a hardware controller.
While RAID 5, RAID 6, and RAID 10 or beyond are suitable for SMBs as they offer both—better read/write performance and redundancy. However, choosing between these RAID levels will entirely depend on your budget and if you want more performance or better redundancy.
Further, remember that relying completely on RAID can be fatal for your data. Use a RAID recovery software such as Stellar Data Recovery Technician to rebuild and recover data from a broken, damaged, corrupt, and failed RAID 0, 5 and 6 arrays in just a few clicks.
To prevent RAID from failing, use Drive Monitor, a utility that comes with Stellar Data Recovery Technician, to keep a check on RAID drive’s health status and replace the impending drive before it leads to RAID failure.
Summary :
RAID 5 is a common RAID setup used frequently in small businesses and other organizations. Like other storage devices, RAID 5 could be corrupted due to different reasons. Once a RAID 5 crashes, data saved there will be put in danger. Now, I will show you how to perform RAID 5 data recovery easily and quickly. Then, tips on how to rebuild a RAID 5 will be given to you.
Quick Navigation :
What Is RAID 5 Data Recovery
RAID (Redundant Array of Independent Disks) actually refers to a data storage virtualization technology which puts multiple physical disk drive components into one or more logical units. Three main purposes of creating a RAID are data redundancy, fault tolerance, and performance improvement (or the combination of them).
Tip: How to recover data from a virtual disk?
Common RAID schemes or data distribution layouts are RAID 0, RAID 1, RAID 5, RAID 0+1, etc. The balance between performance, capacity, reliability, and availability, is different in different RAID levels.
Once you find your RAID is corrupted, you should start to recover data from RAID without any delay. The following content focuses on RAID 5 data recovery only; data recovery from other types of RAID is essentially the same.
The following things need to be identified when you need to recover data from RAID:
- The number of disks that have been used
- The type of parity used in the RAID array
- Disk sequence and block size
- The offset pattern
- …
The RAID 5 partition recovery can be completed as long as the data is found completely and the RAID parameters are set correctly.
RAID 5 Failure
The biggest advantage of having a RAID 5 is: the array will continue to work even when there is one disk in RAID 5 that fails since the parity information is allocated on different drives; this will not cause any data loss.
Situation 1:
If more than 2 drives are failed in the same RAID 5, the array will be broke and data will be put in danger. The array rebuilding requires much time and it is likely to bring drive failure, so you may witness serious disasters during the process. What’s more, it needs to read data from all the disk drives involved when the RAID 5 array is rebuilding; this may result in a second drive failure and the entire array loss.
Situation 2:
If you try to force the array back online when there is one drive failed in RAID 5, the array tends to fail. Despite the fact that RAID 5 can continue to work when one disk is failed and there are most RAID 5 controllers, the force online feature may ruin everything. If the failed disk has been pushed back online by this function, the whole array will be corrupted immediately.
In both situations, you need to follow the steps given below to recover data from degraded RAID without hesitation.
Recover Data from RAID 5 with 2 Failed Drives
Can RAID 5 Lose 2 Drives
All data saved on the disks contained in a RAID 5 will be available (due to parity) unless the disks get failed suddenly.
Can I recover a RAID 5 array if two drives have failed?
I have a Dell 2600 with 6 drives configured in a RAID 5 on a PERC 4 controller. 2 drives failed at the same time and according to what I know a RAID 5 is recoverable if 1 drive fails. I'm not sure if the fact I had six drives in the array might save my skin. I bought 2 new drives and plugged them in but no rebuild happened as I expected. Can anyone shed some light?- asked by bonga86 on serverfault.com
How many disks can you lose in RAID 5?
- If only one of the disks fails, it is easy to recover data from single RAID 5 disk since the reconstruction of RAID 5 will start immediately whenever the hard disk failure is detected.
- In contrast, if two or more disks are corrupted at the same time, all data will be lost.
That is to say, the RAID 5 can survive if there is only one disk damaged. Once you find two or more disks are getting into trouble, you should carry out data recovery from RAID 5 at once.
How to Recover Data from RAID 2 Disk Failure
If you have a single or multiple disks failed in your RAID 5 and the disks contain important data, you need the help of RAID data recovery software.
A program from MiniTool® Software Ltd. called MiniTool Power Data Recovery is regarded as the best RAID recovery software by most users (it can be the good recovery software for RAID 1, RAID 5, and other types of RAID). It can help you recover data from both crashed disk and disks with problematic partitions.
- You should make sure that the configuration tables of the RAID are functional. If you run into the breakdown issue, please fix it properly before you start RAID data recovery.
- If you want to recover data from a drive in RAID 1, you only need to make sure the disk works well.
How to get files off a RAID hard drive:
Step one: get the setup program of MiniTool Power Data Recovery from the reliable link and save it on your computer.
Step two: run the setup program to finish the installation process and make sure your failed RAID disk is connected to this PC.
Step three: launch the RAID recovery software and select the proper function from the left pane.
- Please keep This PC selected if you want to recover files from existing hard drive partitions.
- You should select Hard Disk Drive to recover data contained in a deleted/lost partition.
Step four: double click on the partition/disk that includes the data you want to get back to start drive scan.
Step five: more and more files will be found by the software and you should choose the ones you really need.
Step six: click Save to choose a storage path in the pop-up window. Then, click OK to confirm and wait for the recovery process to complete.
Raid 5 For Macbook
Please note:
You will see the following prompt window when clicking on Save. It indicates that you are using the trial edition of software which only allows you to scan the disk and preview the found files for free. If you need to recover data with it, you’ll need to upgrade to the full version by clicking on the Upgrade Now button.
This method also works when you want to recover data from RAID 0, RAID 1, RAID 0+1…
You should take the following things into consideration when you need to carry out RAID data recovery:
- Can you really afford to lose the data contained in RAID forever?
- How many drives do you have in the RAID array?
- Do you know clearly the order of disks in RAID?
- What are the possible causes of the RAID failure?
- Is the recovery software you choose capable of recovering data from RAID safely?
When the recovery work is done, you should continue to rebuild the failed RAID 5.
Rebuild Failed RAID 5 Yourself
One of the most important reasons why RAID 5 is so popular is that it is tolerant of a single drive failure.
- Once a certain disk failed, RAID 5 will start to rescue data from the entire RAID array by taking advantage of its parity function. In this way, it can calculate the missing data.
- Once there are two or more disks failed, you should hurry to recover data from RAID 5 by using the above method.
When the data recovery is finished, you should try to rebuild the RAID 5. The following actions could help you increase the success rate:
- Turn off your system the moment when you hear weird noises coming from it, so as to prevent further damage.
- Analyze the possible factors causing such failure and evaluating the condition of the disk drives carefully.
- Remember to put the disk drives in order when you remove them from your array.
- You can’t be too gentle when moving around drives getting from RAID.
How to Rebuild RAID 5 without Losing Data
How long does it take to rebuild RAID 5?
Before the rebuilding process, you may ask how much time is needed to complete the process. Actually, there is no definitive answer. The more drives you have and the more capacity you add, the more time you need to rebuild the RAID.
The RAID rebuild time is closely related to two factors: the quantity of data saved on the RAID disks and the capacity of the entire RAID. It is very important for storage administrators, especially enterprise administrators.
How to rebuild with a single disk failed:
- Shut down your device until you know what is going on exactly.
- Take out the failed drive and replace it with a new drive of the same capacity.
- Just wait since the RAID will rebuild itself.
There’s a great chance that you experience a second drive failure during the rebuild process, so you should be alert while RAID is rebuilding. The failure of both another drive and the controller is going to result in a failed rebuild process.
How to rebuild with 2 or more disks failed:
- Recover data from RAID by using the method introduced in the previous part.
- Make sure all the original drives are here and label them in order.
- Send your RAID to a professional recovery company and it will help you get back on track.
Cautions
You should pay attention to the following things to prevent data loss when RAID has been rebuilt successfully.
- Do not create any new files or folders on the disk included in the failed RAID.
- Make an image of the RAID structure in case of any unexpected accidents.
- Create a backup of the disks (or at least essential files) on a separate volume to ensure security.
- Run CHKDSK or use FSCK tool to check for errors when necessary.
- Do not modify (add, move, or delete) data casually.
Here’s how to recover data lost after CHKDSK:
Does CHKDSK utility delete your important data? Here are ways to help your recover CHKDSK deleted files in few steps.
What Is RAID 5 Used for
RAID 5 is one of the most common RAID configurations; it adopts disk striping with parity and consists of at least 3 hard disk drives (at most 16 disks). In a RAID 5 array, you’ll find the data and parity are allocated evenly across the disks contained in the array (they won’t be written to a fixed drive). The data of one of the other data blocks in RAID 5 can be recalculated by the computer using the parity data. That explains why RAID 5 can continue to work after a single drive failure.
Thus, RAID 5 is regarded as one of the most reliable RAID schemes. It greatly improves the bottleneck problem caused by parity data storage.
- The advantage of RAID 5 when compared to RAID 1 and RAID 10: it has more usable storage.
- The performance of RAID 5 is almost equal to that of RAID 0.
Though RAID 5 can be achieved by virtue of software, it is not advisable. A hardware controller is better since extra cache memory can be used on the controller for the sake of improving write performance.
How Does RAID 5 Work
What is striping? It actually refers to storing consecutive segments of data to different disks. This is a good way to get better throughput and performance. Disk striping, together with parity, offers RAID 5 with redundancy and reliability. The benefits of RAID 5 are mainly come from disk striping and parity.
In RAID 5, it is parity, not the popular mirroring, that provides data redundancy. The parity will be calculated by the system and written into the corresponding drive every time new data is written into RAID 5.
What’s the difference between RAID 5 and mirroring?
- In RAID 5, the system will start to rebuild by using the parity data when a drive is failed.
- During mirroring, multiple copies of data will be kept in different volumes at the same time in case of sudden failure.
Data stored on any two drives can be put together to equal to the data stored in a third hard drive after data has been kept on each drive. In this way, even a single drive is failed, RAID data are not in danger. Therefore, disks in RAID 5 are hot-swappable; the failed hard disk can be removed and replaced by a new drive without downtime.
Conclusion
Combining efficient storage, high security, and wonderful performance together, RAID 5 becomes an all-around system. RAID 5 is a good choice for file and application servers which contain limited data drives. It is also important to individual users, enterprises and many organizations. As a result, RAID 5 recovery is important since the loss of data on RAID 5 could bring terrible influences.
Whenever you find your RAID 5 is failed (going to fail), you should carry out RAID 5 data recovery firstly; then, rebuild RAID 5 yourself or by hiring professionals when necessary.