How to Retrieve Deleted Files from Network Attached Storage

Contents

• Why Regular Data Recovery Tools Can’t Restore Files from RAID
• Key Information About the NAS Lenovo ThinkSystem SR655 Rack Server
• 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 Lenovo 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 quality of service (QoS) settings impact data transfer reliability on NAS Lenovo ThinkSystem SR655 Rack Server devices?

Quality of Service (QoS) settings can have a significant impact on data transfer reliability on NAS Lenovo ThinkSystem SR655 Rack Server devices. Here are a few ways QoS settings can affect data transfer reliability:

1. Bandwidth Allocation: QoS settings allow you to allocate bandwidth to different applications or services. By prioritizing critical data transfers, you can ensure that they receive sufficient bandwidth, reducing the chances of congestion or data loss during high network traffic periods.
2. Traffic Prioritization: QoS settings enable you to prioritize specific types of traffic, such as video streaming or VoIP, over others. By prioritizing data transfers, you can ensure that critical transfers are not affected by lower-priority traffic, improving reliability.
3. Packet Prioritization: QoS settings can prioritize packets based on their importance or type. For example, you can prioritize TCP packets over UDP packets or give higher priority to control packets. This helps ensure that important data packets are delivered reliably and in a timely manner.
4. Traffic Shaping: QoS settings allow you to shape the traffic flow, limiting the rate of data transfer for specific applications or services. By controlling the traffic flow, you can prevent network congestion and ensure that data transfers are reliable and consistent.
5. Latency Control: QoS settings can help control latency by prioritizing latency-sensitive applications. This is particularly important for real-time applications like video conferencing or online gaming, where even small delays can significantly impact the user experience and data transfer reliability.

Overall, configuring QoS settings on NAS Lenovo ThinkSystem SR655 Rack Server devices can help optimize network resources, reduce congestion, prioritize critical data transfers, and improve overall data transfer reliability.

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

Although the NAS ThinkSystem SR655 Rack Server 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 Lenovo ThinkSystem SR655 Rack Server. 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 Lenovo

ThinkSystem SR655 Rack Server has 32 HDD slots, and it supports the following array types:

• RAID 0;
• RAID 1;
• RAID 5;
• RAID 6;
• 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 Lenovo ThinkSystem SR655 Rack Server network-attached storage keeps LifeLine 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