Best Practices for Recovering Data from NAS Promise Pegasus3 PC Edition R4 RAID Array Failures

Contents

• Why Regular Data Recovery Tools Can’t Restore Files from RAID
• Key Information About the NAS Promise Pegasus3 PC Edition R4
• How to Remove Hard Disks from Your NAS and Connect Them to a PC
  • Step-by-Step Data Recovery with Hetman RAID Recovery
  • How to Safely Recover Data from Disk Images
  • Where Are the User’s Files Actually Stored?
  • RAID Recovery Software: Detailed Comparison

Why Regular Data Recovery Tools Can’t Restore Files from RAID

Conventional hard drives store user data by writing it sequentially across the disk surface, which means an entire file is typically located on a single drive. In contrast, when data is written to a RAID array, each file is split into multiple fragments. These fragments are then distributed and written in sequence across all the drives in the array. Depending on the configuration, fragment sizes can range from 2 KB to 2 MB, so every file is physically stored across several disks at once.

This approach significantly increases read and write performance — after all, writing two halves of a 1 GB file to two drives simultaneously is much faster than writing the full 1 GB to a single disk. However, this same mechanism makes file recovery far more complex.

Different RAID levels use different methods to distribute and protect data. On top of that, manufacturers like Promise often add their own proprietary structures and variations. As a result, data can be written to disks in many different formats, and each requires a specific approach during recovery.

How can a NAS Promise Pegasus3 PC Edition R4 device's network throughput or bandwidth capacity affect data transfer and potential loss?

The network throughput or bandwidth capacity of a NAS (Network Attached Storage) device like the Promise Pegasus3 PC Edition R4 can significantly impact data transfer and potential loss in the following ways:

1. Data Transfer Speed: The network throughput determines the speed at which data can be transferred between the NAS device and other network-connected devices. Higher throughput allows for faster data transfers, reducing the time required to back up or retrieve files. Conversely, lower throughput limits the transfer speed, resulting in longer transfer times.
2. Latency: Network throughput affects the latency or delay in data transmission. Higher throughput minimizes latency, enabling real-time access to data and smooth streaming of multimedia files. Lower throughput increases latency, leading to delays in accessing or streaming data.
3. Concurrent Users: The network throughput capacity determines the number of concurrent users who can access the NAS device simultaneously without experiencing performance degradation. Insufficient throughput may result in slower data transfers or even connection drops when multiple users try to access the NAS simultaneously.
4. Potential Data Loss: Inadequate network throughput can increase the risk of data loss during data transfer. If the network capacity is lower than the data transfer rate, data packets may be dropped or corrupted, leading to incomplete or damaged files. This can result in data loss or the need to retransfer data, potentially causing inconvenience and additional time consumption.
5. RAID Rebuild Time: The network throughput affects the time required to rebuild a RAID array in case of a drive failure. When a drive fails in a RAID configuration, the data from the failed drive needs to be reconstructed onto a replacement drive. Higher network throughput allows for faster RAID rebuilds, minimizing the time during which the data is vulnerable to loss.

To optimize data transfer and reduce potential loss, it is essential to ensure that the NAS device's network throughput capacity matches the requirements of the network environment, including the number of users, data transfer rates, and the type of data being transferred.

How to Remove Hard Disks from Your NAS and Connect Them to a PC

Although the NAS Pegasus3 PC Edition R4 can be accessed over the network, you still need to remove its hard disks and connect them directly to a Windows PC. Only then can the recovery software properly scan and analyze the drives. Follow these steps:

1. Power off the NAS and disconnect it from the power source.

   WARNING! Before removing any drives, carefully read the device manual. Improper actions may damage both the NAS enclosure and the hard disks in the RAID array.

2. Remove the hard disks one by one, gently sliding each drive out of its slot. Remember that hard disks are highly sensitive: any impact or drop can cause serious physical damage.

3. Label each hard disk according to its position inside the NAS. The order of the drives is crucial for correct RAID reconstruction.

4. Connect the drives to your computer. In this video, we explain which ports you can use to connect hard disks and what to do if your PC does not have enough free connectors.

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   How to Order Remote Data Recovery

Step-by-Step Data Recovery with Hetman RAID Recovery

This program restores data from damaged RAID arrays and is fully compatible with Promise Pegasus3 PC Edition R4. Each hard disk in the array contains technical metadata describing how files were written. When launched, Hetman RAID Recovery analyzes this metadata, automatically reconstructs the damaged array, and provides access to its contents. After that, you can browse the recovered disk and save your files. The program can also restore files that were accidentally deleted from the network drive.

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How to recover data from a Promise

Pegasus3 PC Edition R4 has 4 HDD slots, and it supports the following array types:

• RAID 0;
• RAID 1;
• RAID 1E;
• RAID 3;
• RAID 5;
• RAID 6;
• JBOD;

NAS supports:

• exFAT, VFAT, FAT 12 / 16 / 32;
• NTFS / ReFS;
• APFS / HFS+;
• Ext2 / 3 / 4 / ReiserFS / XFS / UFS / ZFS / Btrfs;
• VMFS / HikvisionFS;

How to Safely Recover Data from Disk Images

This utility allows you to create a complete copy of a disk and work with the disk image instead of the physical drive. This approach helps protect your data from:

• Overwriting during the recovery process;
• Additional data loss caused by bad sectors;
• User errors.

To create a disk image, follow these steps:

1. Ensure you have enough free space to store the image. Its size will typically match the size of the original disk.

2. In the main window, select the target disk and choose Tools - Save Disk. You can also select multiple disks if needed.

3. When the Image Creation Wizard opens, select whether you want to save the entire disk or only a specific region. Adjust the settings and click Next.

   

4. Choose the directory where the image will be saved. You may select any available disk connected to your PC or upload the image via FTP.

   

Where Are the User’s Files Actually Stored?

The Promise Pegasus3 PC Edition R4 network-attached storage keeps OS Linux operating system files on a separate RAID 1 (mirrored) array. Usually, all NAS systems create several volumes on every hard disk, and the first of them takes up to 2 Gb of space. This is where operating system files are stored. Other volumes are united into a RAID array where user’s data is written.

RAID Recovery Software: Detailed Comparison