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Power Outage Causes a Dell EqualLogic System Multiple Hard Drive Failures

Power Outage Triggers RAID System Failures, Requiring Custom Data Recovery Solution

Retail Clothing Store

Recovery Type:
VMware on HDD RAID

Turn Around:
36 Business Days*

Stanford, CT

This case study examines the successful recovery of a 48xHDD 2 Member Dell EqualLogic system, which experienced multiple hard drive failures. The system comprised 44 drives configured as a single storage pool split into two members, each containing two RAID 50 arrays, with an additional four drives serving as unused hot spares.

The complex nature of the data recovery process highlights the expertise and innovative approaches required to retrieve critical data from advanced storage solutions.

Developed Custom Solution

Faced with a proprietary Dell EqualLogic system that defied standard recovery tools, DriveSavers developed a custom solution, successfully recovering crucial data from an extremely complex setup where others might have failed.

Data Loss Situation

During an initial imaging attempt of the drives, images of 43 HDDs were successfully obtained, leaving five drives unimaged. The Dell EqualLogic system used a proprietary mechanism for dynamic block allocation for the Logical Unit Numbers (LUNs), significantly complicating the recovery process. With no commercial tools available to interpret the Dell EqualLogic structures, DriveSavers was contacted for its expertise in managing intricate systems and its reputation for developing specialized tools.

The analysis revealed that all five missing HDDs were part of Member B, affecting one of the RAID 5 arrays with a double failure. The unique architecture of the Dell EqualLogic system meant that an I/O error could lead to exponential data loss, potentially rendering crucial data unrecoverable, especially if vital metadata was affected.

Data Recovery Solution

DriveSavers developed custom tools to interpret and manage the system’s unique structures, addressing the challenges posed by the Dell EqualLogic’s proprietary block allocation mechanism and the significant data loss risk from the RAID 5 double failure. This innovative approach identified the two critical failed drives within the affected RAID 5 array.

Efforts in the cleanroom to extract data from the physically damaged drives proved successful, allowing the logical engineers to start the recovery process on the drive images. This provided access to the system’s contents, including ten different LUNs with sizes ranging from a few GB to 11 TB, formatted in both VMware VMFS and NTFS, containing numerous virtual machines and millions of files.


The recovery of the Dell EqualLogic system demonstrates the complexity and challenges associated with modern data recovery operations, especially when dealing with proprietary and advanced storage technologies.

Through the development of custom tools and the meticulous efforts of the DriveSavers recovery team, crucial data was successfully retrieved from a system that presented multiple layers of failure and data loss.

This case underscores the importance of working with data recovery professionals that have specialized knowledge and experience in developing custom tools in the field of data recovery.

*DriveSavers Standard Turnaround times are 1-2 Business days, Economy 5-7 Business days, and Priority 24/7 service – on occasion, unique circumstances require more time and are approved by the customer.

Data Recovery Options

At DriveSavers, our skilled team is just a phone call away. They’ll work with you directly to discuss the best recovery solution for your needs. While most of our work is conducted at our secure California facility, we recognize that some complex server configurations, such as RAID, NAS, and SAN systems, may necessitate more flexible options to address specific challenges. We offer multiple solutions to accommodate your needs, with the utmost consideration for your company’s security protocols and any relocation limitations.


Most devices are sent for data recovery to our certified secure lab for our Economy, Standard, or Priority data recovery service.


DriveSavers provides a secure Remote Data Recovery service for many data loss situations that do not involve mechanical or physical damage


The Onsite Data Recovery service is available for devices with any data loss scenario, including mechanical or physical damage. 

Mike Cobb, Director of Engineering and CISO
As Director of Engineering, Mike Cobb manages the day-to-day operations of the Engineering Department, including the physical and logical recoveries of rotational media, SSDs, smart devices and flash media. He also oversees the R&D efforts for past, present, and future storage technologies. Mike encourages growth and ensures that each of the departments and their engineers continues to gain knowledge in their field. Each DriveSavers engineer has been trained to ensure the successful and complete recovery of data is their top priority.

As Chief Information Security Officer (CISO), Mike oversees cybersecurity at DriveSavers, including maintaining and updating security certifications such as SOC 2 Type II compliance, coordinating company security policy, and employee cybersecurity education.

Mike joined DriveSavers in 1994 and has a B.S. degree in Computer Science from the University of California, Riverside.

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