No one can predict when data loss from a RAID will occur, but we know it can be catastrophic when it does.

If you suspect a RAID array failure, contact the experts at Ontrack to get your data back as quickly as possible.

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The majority of avoidable data damage happens in the first sixty minutes, the so-called golden hour, after a failure due to human action. Here's a few examples:

  • Swapping wrong disks in the RAID configuration.
  • Raid corruption by replacing incorrect RAID controller.
  • Forcing disks online.
  • Initializing wrong disks.
  • Failed rebuilds.
  • Restores from incomplete backups on the same system.
  • Performing a VMware Storage vMotion when the storage system has failed.

In all these cases it is essential that all activities are stopped and no further changes are written to the original configuration of the system and the individual storage devices itself. A RAID is the base of most of most servers, Network Attached Storage (NAS), and Storage Attached Network (SAN).  It is often not obvious when the RAID is the underlying cause of a problem.

Often you only have one chance to get the system back up and running and to recover stored data. It is essential to reach out to data recovery experts, Ontrack Engineers will help you to determine how to proceed and will inform you about chances, risks and possible next steps.

What to do with RAID failure

Ontrack, your RAID data recovery partner

Acknowledged global data recovery leader Ontrack uses advanced techniques to repair, recover and reconstruct RAID data that has become inaccessible.

Our engineers, backed by 35 years of data recovery research, experience and development, have the knowledge and tools to get your data back. You'll know exactly what data is recoverable before committing to the actual recovery. We perform RAID data recoveries on:

  • Any RAID level
  • Any RAID controller, RAID architecture including software-defined storage(SDS)
  • Any hard drive type, make or model

Ontrack is home to the very largest team of specialists who have conducted more than 500,000 data recoveries. With our unrivaled global expertise, your data is in safe hands.

Discover why Ontrack has the world’s best data recovery technology.


RAID Data Recovery by Ontrack

What are symptoms of a broken RAID? 

Many symptoms can hint there is a RAID array failure. 

Obvious symptoms: 

  • Error messages
  • Beeping sounds / alarms
  • (red) light on the server
  • Drives making noises

Less obvious symptoms:

  • Data corruption
  • Database corruption
  • Unable to access files
  • Logical drives disappearing
  • Lost connection to server, volume, share, LUN
  • Volume down 
  • System speed 
  • System no longer accessible

Common causes of RAID data loss

Each RAID data recovery is unique, but there are a few common causes for data loss.


Mechanical Issues

RAID systems are built to withstand individual drive failure, but once a RAID is running in a degraded state, the workload of the remaining drives increases and so does the risk of additional drive failures. Additional drive failure can lead to failure of the RAID. We have the clean room environment and expertise required to recover data from failed drives, combined with the logical skills and tools to rebuild and repair file systems from failed or partially rebuilt RAID systems.


Power Issues

RAID systems can be affected by loss of power, power cycling and power surges causing loss of data. RAIDs running in a degraded state are especially vulnerable, as power issues can cause out-of-sync drives to be reincorporated into the array. In these cases, our teams have the tools and expertise to map the data and logically rebuild the RAID in order to extract the required data.


Natural Disasters

Fire, water, dirt and other contaminants from natural disasters can destroy a RAID in an instant. Rebuilding file systems from a RAID affected by a natural disaster takes specialized facilities, knowledge and tools to decontaminate the drives and logically rebuild the data. Ontrack has state-of-the-art tools and cleanroom environments to safely recover from physically damaged drives.


Human errors

Whether by accident or completed with malicious intent, data loss from reformatting, reinstalling or volume overwrite can occur throughout any organization of any size. However, with the knowledge and expertise of Ontrack, even the most damaging human error can be conquered by expert data recovery engineers.


Cyber attacks

Whether conducted through computer information systems, computer networks, infrastructures, or personal computer devices, unwelcome attempts to steal, expose, alter and/or destroy sensitive information through data breaches and cyber attacks cause significant data loss. Ontrack has the tools and expertise to safely recover your data from a malicious cyber attack.


Ransomware attack

A form of malware, malicious software that encrypts a victim's files, Ransomware attacks prevent an individual from accessing their computer, or any data stored on it. This form of attack can result in the computer itself becoming locked, or the data on it to become stolen, deleted, or encrypted. Ontrack’s expert data recovery engineers can recover data from a ransomware attack.

What to do when experiencing RAID failure

Before doing anything, answer the following questions:

  • What specifically happened/ how did the event unfold?
  • What data is lost?
  • How critical/valuable is this data?
  • Do I have a backup or other means of getting this data back?
  • What are the financial implications of this data loss?

The answers to these questions will be crucial to determining the data recovery next steps.

Often you only have one chance to get the system back up and running and to recover stored data, so it is important to gather as much information as possible.

RAID Failure, what to do?

Call for RAID recovery

Call for assistance

A free expert consultation will cover...

  • An assessment of the situation, the problem, and possible data loss.
  • Gaining insight into the hardware, RAID configuration, virtualization software, and backup procedures.
  • First aid, advice, and tips to prevent future data loss.
  • Determining whether a Remote Data Recovery (RDR) can be performed.
  • Remote Data Recovery (RDR) Services - In the event that only one hard drive of a RAID is faulty, RDR is the fastest, easiest, and most cost-effective solution. An RDR recovery takes place via an encrypted internet connection directly to your server.
  • Tips and advice on how to shut down the server, pack up the hard drives and transport them safely to our clean rooms.

You can call us around the clock 24/7 for a free consultation. In the event of an emergency, we will take immediate action and try to resolve the problem straight away.

How fast do you need your RAID data back?

We understand the urgent need to recover data and offer service levels to meet your needs.


Average of 7-14 business days


Average of 2-5 business days


24/7 Until Completion

At each service level our engineers analyze your media to determine the condition of the data. As a result, you will be provided an option to receive an online report showing all recoverable files before you decide to proceed with the recovery. After your data is recovered, it's returned on an encrypted external USB drive or made available for encrypted download from a secure server.

RAID Server Data Recovery options

Whether your device has suffered physical damage or undergone a logical failure, we offer you a range of services to match your specific needs.

Our experts are on-hand and will respond to your issue immediately. From assisting with troubleshooting to onsite recovery, our wide range of expert recovery options will ensure you receive the very best solution to solve your RAID data loss problem.



The recovery option to support any type of RAID system, no matter what data loss situation has been experienced. This recovery service is provided in our state-of-the-art data recovery lab and ISO-5/Class 100 cleanroom environment to ensure the safety of your data.


Remote RAID Data Recovery

Your data is recovered remotely without your media ever leaving your premises. We connect to your system via the Internet to perform a live recovery. Available when the storage device or system is still operational.


On-site Recovery

If your RAID system cannot leave your premises, our engineers can bring their recovery expertise to you. This option is only available for emergency service. For on-site data recovery, the storage device or system must be operational.


Custom RAID Data Recovery

We offer custom-designed recovery solutions for proprietary RAID systems and/or highly complex enterprise-level systems. Our R&D team will work with your IT staff to create an emergency solution to retrieve your data.


Client Attended Recovery

A specialist version of our in-lab service for highly confidential and sensitive information. Your team of trusted staff can transport the device to our facilities and stay with it during the recovery process, ensuring the data remains guarded. This service is only offered with the appropriate confidentiality agreements and insurance certificates.

RAID recovery by Ontrack at all levels

Data loss can occur at different levels. Because of the vast amount of experience and patented technology gathered by our global team, Ontrack is able to perform data recovery at all levels.

The first level of data loss begins with the storage medium. This can be a single hard drive or RAID storage with multiple drives (DAS, NAS, SAN). In a recovery for a loss at this level, Ontrack's engineers secure as much RAW data as possible. A copy is made of the working disks and in a clean room our engineers work on the electronics and mechanics to get any defective media operational again, so that the RAW data can be copied. With self-developed and patented tools, the RAID controller is imitated. This can be done even for the complex SAN systems that often lay their own block distribution over a combined RAID system, thus making the lost data visible again.

Layers of RAID data loss

The second level of data loss can begin at a file system level. This can occur if 100% of the RAW data could not be copied from the drives or if that data is damaged. The (virtual) file system is a unique method of storing and organizing system and user files. The operating system controls the file system. If the information about where the files are located on the volume is damaged or lost, Ontrack experts will make adjustments or repairs at a file system level. Once the file system is restored, the data can be accessed again.

Most operating systems have a utility that automatically performs repairs. However, this can permanently damage the data. Always work with a copy. With virtual systems, there is additional complexity due to the combination of the virtual file system and the file systems running within the virtual machines.

The third level of data loss can occur within the file itself, such as SQL, Oracle and Exchange database files. These files can be quite complex. The internal structure can become corrupted to the point where the DBMS makes the database unavailable.

Ontrack has a lot of experience at all these levels, with many complex data recoveries performed.

Our simple 4 step data recovery process

We ensure that our process is transparent, quick and safe. You'll be informed every step of the way for complete peace of mind.



Contact us 24/7 worldwide to obtain a free data recovery consultation and written price quote.



The entire evaluation process is transparent. Once we receive your device, our engineers recommend the best solution, send a fixed price quote and an overview of service levels and delivery schedules.


RAID Recovery 

With your approval, we recover your data based on your chosen service level. Through our secure portal you can track the status of your recovery and view a list of recoverable files. 


Data Return 

Once your data has been recovered, we’ll send it back to you on an encrypted external device via next day delivery free of charge. 

RAID data recovery case studies

RAID Recovery Case Studies

Ontrack uses advanced techniques to repair, recover and reconstruct server data that has become inaccessible. 

Ontrack is highly proactive in keeping up with the incredible technological developments in data storage over the last 30 years. Today, we perform over 50,000 data recoveries per year around the world. RAID data recovery is our passion, and we try to involve our customers in it as much as possible. Our experience and expertise have created the world's best data recovery practices to give our valued customers a sense of confidence.

RAID Recovery Tips

  • Never replace a failed hard drive with one that was previously part of a RAID system – ensure you completely erase the replacement drive before use.
  • If a drive makes unusual mechanical noises, turn it off immediately and seek help.
  • Obtain a bit-by-bit image of the hard disks before making any changes to hardware, software, or performing a RAID rebuild.
  • Label the disks with their position in a RAID array.
  • Do not run recovery programs on suspicious volumes. Volume repair tools, such as CHKDSK are designed to force file systems to a consistent state. This can be useful for a single disk system with simple errors. On a RAID system, inconsistency of a volume can usually be traced to problems with the RAID (i.e. out-of-sync disks, failed rebuild, etc). Using CHKDSK in such scenarios can result in harmful and irreversible changes to the file system.
  • Do not run defragmentation programs on suspected failed disks.
  • Do not run volume recovery programs in cases of a power failure on a RAID array, when the file system looks suspicious or is un-mountable, or the data is inaccessible after power is restored.
RAID recovery tips

RAID Technology Partners

The world's leading technology companies trust Ontrack's expertise for RAID recovery. From LSI MegaRAID to Avago, Broadcom to Adaptec, we collaborate with the world’s leading RAID brands to guarantee the recovery of your important data.

Dell EMC
Western Digital

Most common NAS vendors:

  • Buffalo
  • Synology
  • WD
  • Seagate
  • Thecus
  • Dell
  • NetApp
  • Pure
  • HPE
  • NetGear ReadyNas
  • QNAP

Most common server vendors:

  • HPE/H3C
  • Dell
  • Inspur
  • Supermicro
  • Lenovo
  • NetApp
  • IBM
  • Huawei
  • Fujitsu
  • Cisco

Most common RAID controllers:

  • LSI MegaRAID
  • Avago
  • Broadcom
  • Dell PERC
  • Adaptec
  • Intel RAID
  • HP Smart Array
  • IBM ServeRAID

Enterprise storage:

  • Dell/EMC
  • HPE h3c
  • NetApp
  • IBM
  • Hitachi Vantara
  • Huawei
  • Lenovo
  • Pure storage
  • Nutanix

RAID recovery for virtual environments

Because virtualized systems comprise a unique marriage of software and hardware components, the successful data recovery requires superior knowledge of hypervisors, host machines, storage devices, RAID arrays, file structures, and more.

Ontrack's global team has years of experience and training, a host of proprietary tools, and specialized knowledge gained through unique working relationships with virtual machine software vendors and hardware OEMs that recommend our services. Ontrack virtual machine data recovery experts can help with following:

  • VMware ESX and vSAN (VMDK files),
  • Microsoft Hyper-V (VHD, VHDX, and AVHDX files)
  • Citrix Xen
  • Oracle VM
  • KVM
RAID recovery for virtual environments

Why Ontrack?

We are the global industry leader in data recovery


Recommended by manufacturers


Strict data security protocols


Advanced information security and certifications


Unrivaled global expertise


Highly valued personal service


Toolset covering all layers


Largest team of specialists 


Self-developed & patented tools


Custom build JIT recovery


Proven methods since 1985


500,000+ recoveries


50,000 customers per year

Your data in safe hands - Advanced Information Security

Given the nature of our business, we have been entrusted with large amounts of sensitive and confidential information by our clients and understand that security is increasingly important to today's businesses. We invest significant time and money to protect your most sensitive electronically stored information (ESI).

  • ISO/IEC 27001 certified
  • SOC 2® Certified
  • Accreditation under the EU-U.S. and Swiss-U.S. privacy shield frameworks
  • State-of-the-art information security with defense-in-depth strategy
  • Secure data centers
RAID recovery certified

Join over a half million people and businesses who have trusted Ontrack to recover their data.


Start your RAID data recovery now with a free consultation.

Contact our team of experts for RAID data recovery. Ontrack accommodates everyone – from the largest government or enterprise organization to an individual who may have lost their digital photos and everyone in between.

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