Several brands like QNAP, Synology, and ASUSTOR offer enterprise-grade NAS hardware solutions like NAS boxes, NAS racks, etc. These are affordable, scalable, and easy to manage, which makes them a preferred choice of storage option for small and medium businesses.
A NAS device is usually set up with certain RAID configurations that provide data redundancy and fault tolerance. It also provides overhead and improved read/write performance.
A common notion among new RAID-based NAS users is that the fault tolerance automatically protects against unexpected data loss. But, this is not true as NAS is like any other storage device – prone to data loss due to innumerable reasons. To avoid data loss, optional functionalities like periodic backups, snapshots, off-site backups, and more that come bundled with a NAS device must be configured.
These functionalities, combined with the type of RAID configuration, protect critical business files by providing a robust backup and data recovery plan in the event of data loss.
What Causes Data Loss in NAS?
Some RAID levels, like RAID 5 or RAID 6, are preferred for configuring the member drives of a NAS device as they provide redundancy and fault tolerance through the introduction of parity. Such RAID levels provide a degree of data protection. However, they are not foolproof as drive failure can occur, which could result in an inaccessible NAS. Moreover, critical levels of drive failure exceeding the fault tolerance of the RAID configuration could result in complete NAS failure and permanent data loss.
Hence, it is crucial to understand the various causes of data loss in a NAS that are listed below:
Multiple drive failure in RAID-based NAS: Some RAID configurations provide fault tolerance, which helps the system sustain a certain number of drive failures before complete failure and data loss. For eg, RAID 5 has a fault tolerance of 1 drive failure, and RAID 6 has 2 drive failure. If the number of drive failure exceeds the permissible limits, the RAID configuration fails, leading to complete data loss.
Controller malfunction: Power surges, voltage fluctuations, and frequent power outages can cause the RAID controller to malfunction. This renders the NAS inaccessible to all users.
Improper RAID rebuild: Using incompatible storage drives in an attempt to rebuild the RAID and restore NAS status could end up complicating the situation. Improper RAID rebuilds can cause overwriting of the existing data, leading to permanent data loss.
Human Error: Accidentally deleting files and folders from a shared NAS folder, formatting a complete NAS volume, incorrectly configuring RAID, or replacing failed drive/s can result in data loss.
Firmware issues: Installing an available firmware update may introduce bugs and issues, which could make the NAS device inaccessible to the users, or worse, brick the NAS device, causing data loss.
File system corruption: It is another reason behind a malfunctioning or inaccessible NAS device. It stems from power failures during data write operations, malware attacks, etc.
Environmental factors: Overheating NAS device because of improper ventilation, accumulated dust on the vents, moisture, or extreme temperatures can impact the hardware.
Challenges of NAS Data Recovery
Unlike conventional storage devices that are simple, NAS is a complex storage device. Hence, it presents unique challenges while performing NAS data recovery.
Challenge 1: Proprietary File System
Proprietary file systems like ZFS or BTRFS are used by Synology or QNAP. They have their own metadata structures, data compression, and organization algorithms, which are not supported by all tools. The devices formatted with such file systems require specific tools to recover data in case of accidental deletion, file system corruption, and more.
Challenge 2: Data Encryption
Encryption lets users safeguard critical files and folders from unwanted access. It adds a layer of protection. Performing data recovery on encrypted NAS drives is difficult. However, if the encryption key is lost or the encryption metadata is damaged, the process can become challenging or even impossible.
Challenge 3: RAID Complexity
Recovering data from RAID-based NAS devices is a challenge as it requires knowledge about different RAID configurations and hands-on expertise in dealing with different RAID arrays.
How to recover data from a NAS
A well-laid data recovery strategy is essential for every NAS system. It comprises appropriate steps to take in a data loss event without complicating the situation and optional NAS features deployed to help protect the operational environment and perform data recovery.
Let’s look at both aspects in detail.
Essential steps for recovering data from a NAS device:
Step 1: Identify the type of Failure
The initial step helps you diagnose the type of problem with the NAS device. Here, you can identify whether the issue is physical in nature or logical. This helps devise a suitable plan for data recovery.
Physical issues involve hardware failure, like clicking or grinding sounds from the drive/s, controller failure, etc. Logical issues are error messages, missing files, or the NAS not showing on the system.
Step 2: Check NAS Logs to Understand the Problem
You can check the logs of your NAS to get in-depth details of the problem encountered. Log file contains a record of all activities happening on your NAS device along with timestamps. This helps understand the problem and solve it.
Step 3: Take Necessary Action
Most enterprise-grade NAS devices employ RAID configuration. Hence, you can check the status of the member drives and locate faulty drives within the NAS management software. You can identify the faulty drives and replace them with healthy drives. The controller will automatically rebuild the array and the data on the failed drive.
Step 4: Recover Data
In case the number of failed drives exceeds the fault tolerance of the selected RAID configuration, you can recover lost data using data backups created using off-site or cloud backups, snapshots, etc.
You can also use a specialized software like Stellar Toolkit for Data Recovery to streamline the data recovery process. It is an advanced NAS data recovery software that is capable of recovering data lost from a NAS device in various situations, such as accidental deletion, volume formatting, member drive failure, etc.
In case you have a failed RAID-based NAS device, you need not worry. You can use this software to recover data from it. But to do this, you should know the type of RAID configuration and the number of failed drives. For example, a RAID 5 array can withstand one drive failure, while a RAID 6 array can withstand two drive failures.
Step 5: Contact Professional Services
If the problem is beyond the scope of the above workarounds, you should immediately stop using the NAS and contact a professional data recovery service.
Conclusion
NAS is a complicated device that requires expertise and specialized tools to recover lost data. Several features, like Snapshots, versioning, off-site and cloud backups, can help you recover files lost due to accidental deletion, volume formatting, member drive failure, or any other reason. Hence, if you are looking for a way to recover data from a NAS device, the easiest way to do it is to use a NAS data recovery software such as Stellar Toolkit for Data Recovery. It is a simple-to-use DIY software that helps you recover lost files and folders from a NAS or RAID-based NAS without any hiccups.
