Best Practices for Data Recovery from a Failed NAS Promise SmartStor A4R-CLD RAID Configuration

Contents

• Why can’t ordinary software tools restore files from RAID?
• How to take hard disks out of the NAS and connect them to a PC?
  • Restoring data with Hetman RAID Recovery
  • Safe recovery from disk images
  • Where are user’s files stored?
  • Comparison of software for RAID recovery

Why can’t ordinary software tools restore files from RAID?

Conventional hard disks keep user’s data by writing it to their surface in a consecutive way, and this is how an entire file is stored on a single hard disk. However, when data is written to a RAID system, a file is divided into several parts. Then these parts are written consecutively to all hard disks within such array. The size of such parts may range from 2 KB to 2 MB, so each file is stored on several hard disks at the same time.

Such approach helps to speed up read and write operations, and it is evident that saving two parts of a file having the size of 1 GB to two hard disks simultaneously is much faster than saving the same 1 GB of data to one hard disk. However, this peculiarity makes file recovery more complicated.

Various RAID levels store information in different ways. Additionally, manufacturers like Promise also introduce some modifications to this process, and that is why data can be written to hard disk in a wide variety of ways.

Are there any specific factors to consider when choosing a NAS Promise SmartStor A4R-CLD device to minimize data loss risks?

Yes, there are several factors to consider when choosing a NAS (Network Attached Storage) device like the Promise SmartStor A4R-CLD to minimize data loss risks. Here are some important factors to consider:

1. Redundancy: Look for a NAS device that offers redundancy features such as RAID (Redundant Array of Independent Disks). RAID configurations like RAID 1, RAID 5, or RAID 6 can help protect against data loss by storing redundant copies of your data across multiple drives.
2. Drive Failure Protection: Check if the NAS device has built-in features like hot-swappable drive bays or drive monitoring tools that can detect and alert you to potential drive failures. This allows you to replace a failing drive without downtime and minimize the risk of data loss.
3. Backup Options: Consider if the NAS device supports automatic backup options to external storage devices or cloud storage services. Regularly backing up your data is crucial to minimize the impact of data loss in case of NAS failure or other disasters.
4. Power Protection: Look for a NAS device that includes features like an uninterruptible power supply (UPS) support or power loss protection mechanisms. These features can help prevent data corruption or loss due to sudden power outages or voltage fluctuations.
5. Network Security: Ensure that the NAS device offers robust security features such as user authentication, access controls, data encryption, and firewall protection. This helps safeguard your data from unauthorized access or potential cyber threats.
6. Scalability: Consider the future growth of your data storage needs. Choose a NAS device that allows for easy expansion by supporting additional drives or storage expansion units. This will help avoid data loss risks due to running out of storage space.
7. Data Recovery Options: Check if the NAS device provides data recovery options in case of accidental deletion or file corruption. Some devices may offer features like file versioning or recycle bin functionality, which can help recover lost or modified files.
8. Manufacturer Support: Research the reputation and customer support track record of the NAS device manufacturer. Look for a reliable and reputable brand that provides regular firmware updates, security patches, and responsive technical support.

By considering these factors, you can minimize the risk of data loss and ensure the safety and availability of your important files and data on the NAS device.

How to take hard disks out of the NAS and connect them to a PC?

Although NAS SmartStor A4R-CLD can be accessed over the network, you still need to take the hard disks out of the storage device and connect them to a Windows computer. Only in this case will the software be able to scan them properly. Here is what you should do:

1. Turn off the storage and disconnect it from the power supply.

   WARNING! Before you start taking hard disks out of your NAS device, read the manual carefully. Incorrect actions may damage your network-attached storage and/or the hard disks within the RAID system.

2. Take the hard disks out of the NAS one by one, carefully removing them from their slots. Remember that the disks are extremely vulnerable: hitting or dropping them may result in serious physical damage.

3. Make sure to mark each hard disk in accordance with how they were installed inside the NAS.

4. Remove the hard disks and connect them to the computer. In this video, we have explored what ports are used to connect hard disks, and what to do if there are not enough ports or connectors.

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   How to Order Remote Data Recovery

Restoring data with Hetman RAID Recovery

This program recovers data from damaged RAID arrays and is fully compatible with Promise SmartStor A4R-CLD. The hard disks that make up the RAID contain technical information about the algorithm used to save files. When launched, Hetman RAID Recovery reads this information and puts the damaged array together. Then you can open the disk and save your files. Also, you can recover the files accidentally deleted from the network drive.

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How to recover data from a Promise

SmartStor A4R-CLD 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;

Safe recovery from disk images

This utility lets you save an entire copy of the disk to file and then work with this image instead of the actual disk. Such feature helps to protect data on the disk from:

• Overwriting during the recovery process;
• Loss resulting from bad sectors;
• User mistakes.

To create an image, do the following:

1. Make sure that you have enough free space to save the image. The image file size usually equals the disk size.

2. Select the disk in the main window, and choose from the menu Tools – Save Disk. You can select multiple disks to be saved.

3. When the image creation wizard starts, you can choose to save the entire disk or select only a part of it. Specify the parameters and click Next.

   

4. At this stage, you need to choose a directory where to save the image. Choose any disk connected to this PC, or save the image by FTP.

   

Where are user’s files stored?

The Promise SmartStor A4R-CLD 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.

Comparison of software for RAID recovery