Professional Tips for Recovering Data from a Failed NAS Promise VSky s420 RAID Array

Contents

• Why Regular Data Recovery Tools Can’t Restore Files from RAID
• Key Information About the NAS Promise VSky s420
• 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 regular disk health monitoring and analysis help in preventing potential data loss on NAS Promise VSky s420 devices?

Regular disk health monitoring and analysis can help in preventing potential data loss on NAS Promise VSky s420 devices by:

1. Early detection of disk failures: Disk health monitoring tools can constantly monitor the health and performance of individual disks in the NAS device. By regularly checking the SMART (Self-Monitoring, Analysis, and Reporting Technology) data of the disks, any signs of potential failures or degradation can be identified early on. This allows for proactive actions to be taken, such as replacing the failing disk before it completely fails and causes data loss.
2. Predictive analysis: Disk health monitoring tools often provide predictive analysis capabilities. They can analyze the historical performance data of the disks and identify patterns or indicators that may lead to potential failures. By using this predictive analysis, administrators can take preventive measures, such as migrating data from a disk showing signs of degradation to a healthier disk, reducing the risk of data loss.
3. RAID monitoring: NAS devices like Promise VSky s420 often use RAID (Redundant Array of Independent Disks) configurations for data redundancy and protection. Disk health monitoring tools can monitor the status of the RAID arrays, ensuring that all disks are functioning properly and the redundancy is maintained. If a disk fails or shows signs of failure, the monitoring tool can alert the administrator to take immediate action, such as replacing the failed disk and rebuilding the RAID array to avoid data loss.
4. Proactive maintenance and replacement: Regular disk health monitoring allows administrators to identify disks that are nearing their end of life or have a higher probability of failure. By proactively replacing these disks before they fail, the risk of data loss is significantly reduced. Monitoring tools can provide alerts and notifications when disks reach certain thresholds or exhibit abnormal behavior, enabling administrators to plan and schedule maintenance activities.
5. Performance optimization: Disk health monitoring and analysis can also help optimize the performance of the NAS device. By monitoring the performance metrics of individual disks, administrators can identify bottlenecks or underperforming disks and take corrective actions. This can involve redistributing data across disks, optimizing RAID configurations, or upgrading disks to higher-capacity or faster models. Improved performance reduces the chances of data loss due to slow or unresponsive disks.

In summary, regular disk health monitoring and analysis on NAS Promise VSky s420 devices can help prevent potential data loss by detecting disk failures early, predicting failures, monitoring RAID arrays, facilitating proactive maintenance and replacement, and optimizing performance.

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

Although the NAS VSky s420 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 VSky s420. 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

VSky s420 has 37 HDD slots, and it supports the following array types:

• RAID 0;
• RAID 1;
• RAID 1E;
• RAID 3;
• RAID 5;
• RAID 6;
• RAID 30;
• RAID 50;
• RAID 60;
• 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 VSky s420 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