The Ultimate Guide to Recovering Data from RAID Drives
RAID storage technology is more like the trend nowadays. It is not being deployed by home users, not only in business environments. The reason is simple, RAID offers more flexibility and advanced data redundancy features than single-drive storage. There are more than 10 types of RAID storage, but only a few of them are very popular and commonly used.
Each type of RAID level offers unique data storage benefits and you can set them up using an external hardware controller or your system’s hardware resources. However, it is important to note that although some RAID levels offer high fault tolerance and data redundancy, it is still advisable to make a local backup of the data you save on your RAID storage.
What is RAID: Definition, Types, and Configuration?
RAID, short for Redundant Array of Independent Disks, is a storage technology employed by IT admins and data experts to achieve data mirroring, stripping, or both mirroring and stripping across multiple hard drives arranged in a particular order.
Some RAID types can offer fault tolerance until there is no more good drive in the array; this means, that even if you experience multiple drive failures, your files will still be accessible until the very last drive in the array fails.
Equally, there are RAID types that do not offer any fault tolerance, once there’s a failed drive in the array, every data on the RAID becomes inaccessible. Thus, it is important that you know the different types of RAIDs that exist and their features.
You can easily count up to ten (10) different RAID types (referred to as RAID levels), and each is configured differently to achieve data stripping, mirroring, or both techniques. The various known RAID levels are: RAID 0, RAID 1, RAID 2, RAID 4, RAID 5, RAID 6, RAID 1+0, RAID 0+1, RAID 0+3, RAID 5+0, and RAID 6+0. But not all these RAID levels are being used in today’s world.
The two main data storage techniques used by RAID levels are data mirroring and data stripping.
Data Mirror is a technique where data is mirrored across paired disks in the same manner; so, all disks in the array contain the same data blocks and information. In this case, your data will continue to be accessible as long as there’s at least one good drive in the array. RAID levels that support data mirroring can survive multiple disk failures at the expense of offering minimal storage space.
On the other hand, data stripping is a technique where data is stripped in bits or blocks and saved across the member drives in the array. Some RAID levels that support this technique require an additional drive (or 2 drives as in RAID 6) for parity storage. While data stripping will allow you to use a greater space of your combined hard drives, RAID levels that support this technique have a limited number of drive failures they can survive.
RAID Levels Explained: From 0 to 10
- RAID 0 – striping
- RAID 1 – mirroring
- RAID 5 – striping with parity
- RAID 6 – striping with double parity
- RAID 10 – combining mirroring and striping
1. RAID 0
Use Cases: Where faster read and write performance is required.
Advantages: No overhead, more storage space, minimum of 2 drives is needed.
Disadvantages: Zero fault tolerance, one drive failure will lead to fatal data loss.
RAID 0 is commonly referred to as “Striping” because it supports data striping. In RAID 0, data is stripped into blocks and saved uniquely across all member drives in the array. This technique promotes improved I/O speeds and more space for data storage, but there’s no room for parity or fault tolerance. A single drive failure in RAID 0 can lead to complete data loss.
2. RAID 1
Use Cases: Environments where data reliability and availability are in high demand
Advantages: High fault tolerance, your data will still be accessible until the last drive in the array fails, and no rebuilding process is needed.
Disadvantage: The total storage space you get is equal to the total storage offered by the smaller drive in the array.
RAID sounds all interesting when you hear that you can still access data in the array even if multiple drives fail. But, it does this at the expense of “free space.” This RAID level supports data mirroring, where the same data is mirrored across all member drives. So, if you have two or four drives in the array, all of them will contain the same data. This way, the total storage of the array is equal to the total storage of one drive in the array – since all drives get the same data stored in them.
3. RAID 5
Use Cases: Suitable for all kinds of data storage deployment
Advantages: Redundancy, automatic rebuild if one drive fails, quite easy to set up, decent read/write speeds, reasonably available storage.
Disadvantage: Only one drive failure is allowed, multiple drive failures will lead to data cost, and you need a dedicated drive for parity, which means additional setup cost.
RAID 5 is considered the best type of RAID level to set up at the moment. It supports data stripping and parity – the parity information is saved on a dedicated drive. So, to set up a RAID 5, you need at least three disks: two drives for data storage and the other drive for parity data storage. This makes RAID 5 a little bit more expensive to set up than RAID 1 and RAID 0.
Of course, you can set up RAID 5 with more than 4 drives if you wish. Because of the dedicated parity drive, if one drive fails in a RAID 5 array, once the failed drive is replaced with a new (good) drive, the RAID array will automatically rebuild itself, thanks to the parity data. When new data is written to a RAID 5, the data is stripped and saved in bytes across the data drives, while a parity checksum of the block data is saved to the parity drive.
4. RAID 6
Use Cases: In data environments where faster data read is required.
Advantages: High redundancy, automatic rebuild if two drives fail, decent read/write speeds, reasonably available storage.
Disadvantage: Only two drive failures are allowed, additional cost for the needed two parity drives, and slow write performance.
RAID 6 and RAID 5 and practically the same, except that RAID 6 is more complex to set up and requires dedicated two parity drives. To set up RAID 6, you will need at least four drives: two drives for data storage and two drives for parity storage.
Also, RAID 6 uses the data stripping technique as in RAID 5; new data is stripped and saved across the data disks, while parity information of the block data is saved to the dedicated parity disks. While this RAID may offer faster reads, the write speed is slower due to the dual parity drives.
5. RAID 1+0 (RAID 10)
Use Cases: In data environments where RAID rebuilding is expected to take as little time as possible to avoid severe downtime.
Advantages: RAID 1 mirroring guarantees high redundancy, and read and write speeds are fast due to RAID 0 striping.
Disadvantage: You only get 50% of the total storage for storing data, expensive to set up.
Although written as RAID 10 most times, this does not mean RAID ten, but RAID 1 + RAID 0. This RAID level is nested to offer two different RAID data storage techniques simultaneously. It supports both data mirroring (RAID 1) and data striping (RAID 0). You need at least four drives to set up this RAID, but unlike in RAID 6, all drives in RAID 10 are data blocks.
Here’s how this RAID is configured, first, you make two or more pairs of RAID 1 array (depending on the number of disks you’re using) and then strip the pairs (RAID 0). So, first, as data gets into the array, the data is stripped and then mirrored. RAID 10 offers improved speeds and high fault tolerance, but you will only get half of the total storage of all hard disk drives used in the setup.
RAID Configurations: Hardware vs. Software RAID
To set up a RAID level, you need a RAID controller; this RAID controller can be hardware or software. Hardware controllers obviously help to improve the RAID level’s performance, while software controllers may perform slower because they draw power from the host system’s hardware.
A hardware controller is an external device that allows you to create specific RAID levels on a computer. When you create a RAID level using a hardware controller, the hardware controller is what processes data storage on the RAID drives. Every RAID controller has specific RAID levels it is designed to support – you will see the supported RAID levels in the user manual.
On the other hand, and as the name implies, a software controller is installed on your computer to allow you to set up specific RAID levels. Just like external RAID controllers, software controllers also have specific RAID levels they can create – your software RAID controller provider will tell you the supported arrays. The controller type processes RAID data storage of the host system’s CPU and motherboard.
However, hardware and software RAID controllers have unique advantages and disadvantages. One major advantage of hardware RAID controllers over software RAID controllers is the faster processing speed they have. But then, if you decide to go with hardware RAID, you will be spending additional money to buy it – after you must have bought the drives you want to use in the array. A hardware controller can cost from $100 to $1,500.
Software RAID controllers, on the other hand, may not offer the same high-speed processing times as their hardware components, but you’ll most likely not be spending any additional cost if you choose this RAID controller type.
Controller Type | Hardware | Software |
Installation pattern | Connect externally | Install the program |
Cost | $100 - $1,500 | Usually free to install |
Performance | Faster speeds | Decent speeds depending on your system specs |
Supported RAID levels | Depends on the one you buy | Depends on the software provider |
Ease of use | Good | Better |
Common Causes of RAID Drive Failures
RAID drives are subject to failures for the same scenarios that may trigger such on single-drive storages as well. That said, there are a couple of things to look out for when using RAID storage – to avoid facing multiple drive failures that may cause severe data loss.
1. Hardware Malfunctions and Component Failures
If you’re using software RAID and the host system’s motherboard gets damaged or fried, your RAID level will fail, however, there may be no data loss as the hard drives won’t be affected. On the other hand, if you set up a hardware RAID and your hardware controller fails, the RAID will equally fail.
2. Software Corruption
If your RAID level is managed by a managed by a software application, apparently, any corruption of the software files will lead to the RAID failure and consequentially, data loss. There are many reasons for software corruption, including virus attacks and software file conflicts.
3. Power Surge
A sudden power surge can damage RAID controllers and the RAID drives. It is important to maintain a stable power supply to your RAID system. RAID failure due to a power surge can cause logical damage to hard drive partitions and volumes, which could lead to data loss.
Preparing for Data Recovery: Best Practices
Preparing for data recovery involves meticulous planning and the implementation of robust strategies to ensure data integrity and availability. Here's a breakdown of best practices in two key areas: Assessing the Scope of Data Loss and Backup Strategies for RAID Systems.
Assessing the Scope of Data Loss
Initial Analysis: Begin with a comprehensive analysis to understand the extent and type of data loss. This involves identifying the cause of the loss, whether due to hardware failure, software issues, human error, or malicious activities.
Prioritization of Data: Not all data is of equal importance. Classify the data based on its criticality to your operations. This helps in prioritizing the recovery efforts to first target the most critical data, ensuring minimal operational disruption.
Utilization of Diagnostic Tools: Employ diagnostic tools and software to gauge the severity of the data loss. These tools can provide insights into recoverable data and the health of your storage devices.
Documentation: Keep detailed records of the findings and the steps taken during the assessment phase. This documentation is invaluable for post-recovery analysis and for preventing future data loss incidents.
Consulting with Experts: In complex cases, it might be necessary to consult with data recovery experts. These professionals can offer deeper insights into the scope of data loss and the best path forward for recovery.
Backup Strategies for RAID Systems
RAID (Redundant Array of Independent Disks) systems offer built-in redundancy for data protection, but they are not immune to data loss. Implementing strategic backups for RAID systems is crucial.
Understand RAID Levels: Different RAID levels offer varying degrees of redundancy and performance. Understanding the specifics of your RAID configuration (e.g., RAID 0, 1, 5, 10) is crucial for tailoring your backup strategy to match your data protection needs.
Regular Backup Schedules: Implement a regular schedule for backups, ensuring that data is backed up frequently. The frequency should align with the volume of data changes and the criticality of the data.
Off-site and On-site Backups: Maintain both off-site and on-site backups. Off-site backups protect against physical disasters, while on-site backups allow for quicker recovery times in the event of data loss.
Test Your Backups: Regularly testing your backups is essential to ensure they are both complete and recoverable. This step is often overlooked but is critical for guaranteeing that your backup strategy is effective.
Use of Cloud Backup Solutions: Integrating cloud backup solutions can provide additional redundancy and scalability. Cloud backups can complement your existing on-site and off-site backup strategies, offering a flexible and cost-effective solution for data protection.
Monitoring and Alerts: Implement monitoring systems to alert you of any issues with your RAID arrays or backup processes. Early detection of problems can prevent data loss or minimize its impact.
By adhering to these best practices in assessing the scope of data loss and implementing effective backup strategies for RAID systems, organizations can significantly reduce the risks associated with data loss and ensure business continuity.
Tools and Techniques for RAID Data Recovery
Data recovery from RAID systems requires a nuanced approach, leveraging both specialized tools and a methodical process. RAID systems, by design, offer redundancy and performance enhancements across multiple disks, complicating recovery efforts when failures occur. Below, we delve into the tools and techniques for RAID data recovery and outline a step-by-step process for recovering RAID arrays.
Tools and Techniques for RAID Data Recovery
Utilizing RAID Recovery Software
- Selection of Software: Choose RAID recovery software that supports the specific RAID configuration used (e.g., RAID 0, 1, 5, 10). Look for features like automatic RAID parameter detection, support for various file systems, and the ability to work with disks from failed RAID arrays.
- Software Features: Effective RAID recovery software should be able to reconstruct RAID arrays, recover lost RAID configurations, and retrieve data from damaged disks within an array. It should also offer a preview of recoverable files, helping prioritize the recovery efforts.
- Recovery in a Safe Environment: Opt for software that operates in a read-only mode to prevent further data loss. Some tools allow for the creation of a disk image, enabling recovery efforts to occur on the image rather than the physical disks, further safeguarding the data.
Step-by-Step RAID Data Recovery Process
Initial Assessment and Diagnosis
- Determine the RAID Level: Understanding the RAID level is crucial for planning the recovery process. Different RAID levels have different data distribution methods and redundancy mechanisms.
- Identify the Failure Mode: Determine whether the failure is due to hardware (disk failure, controller issues) or software (corrupted data, lost RAID configuration).
- Evaluate the Data Loss Impact: Assess which data is at risk and prioritize the recovery based on the importance of the data and its role in business operations.
Recovering RAID Arrays
1. Stop Operations on the RAID Array: To prevent further data loss or overwrite, immediately stop all operations on the affected RAID array.
2. Create Disk Images: If possible, create sector-by-sector images of the disks within the RAID array. This step allows for data recovery efforts to be conducted on the disk images, preserving the original disks from potential harm during the recovery process.
3. Reconstruct the RAID Array: Using RAID recovery software, attempt to reconstruct the virtual RAID array. This may involve manually inputting RAID parameters or relying on the software to automatically detect and reconstruct the RAID configuration.
4. Scan for Recoverable Data: Once the RAID array is virtually reconstructed, perform a deep scan to locate and recover lost or deleted files. High-quality recovery software can often recover files even from severely damaged RAID arrays.
5. Restore Data to a Secure Location: Carefully restore recovered data to a secure location that is separate from the original RAID system. This could be an external drive, another storage system, or a cloud storage service.
6. Verify Data Integrity: After recovery, verify the integrity and completeness of the recovered data. Ensure that critical files are intact and can be accessed as expected.
- 7. RAID System Restoration or Rebuilding: After successful data recovery, address the underlying issues with the RAID array before returning it to service. This may involve replacing failed drives, rebuilding the RAID array, and restoring data from backups.
How to Recover RAID Arrays by DiskInternals RAID Recovery Software
DiskInternals RAID Recovery is a professional solution for recovering lost data from all known RAID levels, regardless of the controller type (software or hardware). The software features an intuitive interface and comes with a built-in recovery wizard to guide you throughout the process.
This RAID recovery program runs on all Windows OS versions and editions, including Windows Server OS. Also, it supports all known Windows and Linux OS file systems, as well as offers a “Preview” function so you can preview the retrieved “lost” files before actual recovery.
DiskInternals RAID Recovery is free to install and use; the only time you will pay is when your files have been successfully recovered. The DiskInternals RAID Recovery software is efficient for the following conditions:
Repairing software or hardware RAID
- RAID failure due to controller issues
- RAID data loss due to power surge
- RAID disks not getting recognized by the system
- And other scenarios
Guide:
- Step One: Download and install DiskInternals RAID Recovery on your Windows PC and launch it.
- Step Two: Connect the failed RAID drives to the computer where DiskInternals RAID Recovery is installed.
- Step Three: Follow the Recovery Wizard prompt for automatic recovery following the on-screen instructions. You can close the wizard interface if you want to do a manual recovery.
- Step Four: Select the failed RAID drive and choose recovery mode (preferably, Full Recovery). This software will read the drive and automatically check the current status of the RAID array, controller, and file system.
- Step Five: After the scan, DiskInternals RAID Recovery will show you all your lost files (they will appear with a red asterisk). You can prevent most of these files and recover them to another storage.
Note: If you can’t retrieve your lost files through this method, you can request for DiskInternals Guided Repair service to have a data expert do the recovery on your behalf.
How to Prevent Future RAID Data Loss
- Always check the status of your RAID drives; if any of the drives start showing signs of failure, replace them sooner before they actually fail.
- Parity data is not the same as backup, even if you’re running a high redundancy RAID level, always make local backups.
Conclusion:
Data loss will always occur at some point, it could be due to human error or system error. The best thing to do in a data environment is to be prepared ahead by making local backups and keeping a recovery program handy. RAID storages are faster and more efficient than single-drive storages, but they are not immune to drive failures and other data loss concerns.
FAQ
How much does it cost to recover data from RAID?
The typical expense for retrieving data from prevalent RAID setups ranges from $300 to $1,900. Specialists in RAID recovery determine the price based on factors such as the complexity and nature of the failure, the challenge faced by the engineer in restoring your data, and the total hard drives within your RAID configuration.
How do I recover my RAID configuration?
Recovering your RAID configuration using DiskInternals RAID Recovery involves a few straightforward steps, thanks to its user-friendly interface and powerful recovery engine. Here’s a detailed guide to help you through the process:
- Download and Install DiskInternals RAID Recovery: Begin by downloading the RAID Recovery software from the DiskInternals website. Follow the installation instructions to install it on your computer.
- Launch the Software: Open DiskInternals RAID Recovery. The software will prompt you with a wizard to assist you throughout the recovery process, making it easier to navigate through the steps.
- Select the RAID Recovery Mode: Choose the RAID recovery mode that matches your needs. You can select either "Automatic Detection" for the software to automatically identify and reconstruct your RAID configuration or "Manual Mode" if you prefer to specify the RAID parameters yourself.
- Scan Your RAID Array: Once the RAID configuration is identified or entered, the software will begin scanning the disks for recoverable data. This process can take some time, depending on the size of the drives and the extent of the damage.
- Preview and Recover Files: After the scan is complete, DiskInternals RAID Recovery will display a list of recoverable files. You can preview these files directly within the software to verify their integrity. Select the files you wish to recover and choose a safe location to save them, ideally on a different drive to avoid potential overwriting of data.
- Save the Recovered Data: Once you have selected all the desired files, proceed to save them. You will need to have a license key to save the recovered files. If you haven’t already purchased a license, you can do so from the DiskInternals website.
- Restore RAID Configuration (if applicable): If your goal was to recover the RAID configuration itself, ensure that you carefully follow the instructions provided by the software to restore or rebuild your RAID array based on the recovered configuration data.
Tips for Success:
- Ensure that all RAID drives are connected to your computer before starting the recovery process.
- Avoid installing the software on the disk where data recovery is to be performed to prevent data overwriting.
- Consider using a professional data recovery service if the RAID configuration is heavily damaged or if you’re unsure about the recovery process.
Which RAID is best for data recovery?
RAID 1 should not be considered a replacement for comprehensive backups. Meanwhile, RAID 5 provides a harmonious balance of benefits, enhancing speed, capacity, and data security. It employs disk striping with parity, distributing both user data and parity evenly across all disks in the array, thereby eliminating any single disk as a potential bottleneck.