The server/NAS does not start and the RAID has the status "degraded"
Don't force reconstruction. First we check disk order, matrix parameters and secure the reading.
Dysk i Spółka • RAID/NAS
RAID and NAS data recovery in Warsaw
When an array goes degraded, offline or loses a volume, the order of actions matters. We preserve the disk order, image member drives and reconstruct the RAID on copies.
RAID 0/1/5/6/10
NAS/servers
Disk copies
Restoration of RAID only after diagnosis of the system
Response to the RAID/NAS incident
Array degraded/offline? Do not run a rebuild without protection.
The greatest losses in RAID/NAS occur after chaotic repair attempts. Stop writing, preserve disk order, and consult next steps before rebuilding.
- Do not run a rebuild without a copy of the member drives.
- Do not insert new disks "to test".
- Do not reset the controller or NAS configuration.
- Label the order of drives and bays.
- Shut down the server/NAS if continued operation poses a write risk.
- Give a brief description of the symptoms and messages from the matrix.
RAID array failure: what to do before rebuilding or reset
In the event of a crash, RAID first stop the recording operations. Unrethinkable reboot, RAID restoration, initialization or configuration reset can override metadata and hinder reconstruction. If the shares are missing, NAS does not mount the volume or rebuild is stuck, do not make further attempts on the originals.
In the laboratory we reconstruct among others. RAID 0, RAID 1, RAID 5, RAID 6, RAID 10, RAID 50 and the environment of HDD, SSD/NVMe, NAS Synology/QNAP and VMware / Hyper-V / SAN. We work on sector copies.
The most important are: device model, number of disks, order of media and history of operations. If the problem concerns the company NAS, server or VMware/Hyper-V, we treat it as an analysis of the data system, not a standard service intervention.
After contact we accept a matrix or NAS in Warsaw in Białołęka. We're preparing a shipment of disks for the lab.
Enter the device model, number of disks, matrix status, last message and information about the restoration of the RAID, configuration reset or replacement of the media.
Diskraid matrix failure symptoms – what you see as a user
The order of action is important in the matrix. Failed reconstruction may make the situation worse, so it is worth recognizing the symptoms first and stopping operations that change the data system.
The failure of the RAID array can manifest in many ways. Most often the administrator notes the message "Degraded", the lack of one of the disks in the matrix or the sudden disappearance of network volumes.
Typical symptoms include file reading errors, lack of access to network shares, or a situation where the RAID controller ceases to recognize matrix configuration.
Shares/folders disappeared and the system asks for initialization
Don't initialize volumes. First we play matrix parameters: order, stripe and offset.
RAID restoration stuck after disk replacement
Stop the rebuild. We're working on copies, and we're checking to see if another attempt can make it worse.
Common RAID/NAS mistakes to avoid:
If the system asks to format the drive, do not confirm it. stop the server if saving is ongoing, note down the messages and do not start another restoration.
If this is a Synology or QNAP device, see also related paths:
The most common technical challenges in RAID arrays
The most common failure of the RAID/NAS with which they enter the laboratory
- RAID with the message degraded does not start after restart or power outage
- Rebuild failed after replacing the disk (risk of overwriting and loss of consistency)
- File system errors (EXT4/XFS/Btrfs) – RAW volume, no mounting
- Corrupt RAID metadata (disk order, stripe size, parity)
- RAID controller/firmware failure
- NAS reset/volume deletion/format
- Ransomware in a NAS/server environment (encryption + deleted snapshots)
The problem in the RAID system rarely affects only one disk. Most often it is a complex logic failure or a serious deterioration of the situation following an operator error.
1. Virtual configuration reconstruction – reconstructing logical structure
We analyze parameters such as block size (Stripe Size), disk order and offset to build a stable reading environment without interference with physical media.
- How we work: Recovery is about virtual matrix reconstruction in a controlled laboratory environment. First, we do sectoral images of disks. Then, with the use of PC-3000 Data Extractor, we play matrix configuration parameters: disk order, RAID level, block size (Stripe Size) and rotation direction.
2. Damage to member disks and loss of parity
In case of simultaneous failure of more disks than is allowed by a particular level of RAID (e.g. two disks in RAID 5), it is necessary to recover data from damaged member disks, often with loss of sectors.
- How we work: Even in the most difficult cases, we are working on partial reconstruction and advanced recovery of data from damaged media to minimize data loss.
3. Controller faults and server system software failure
A hardware or software failure of the RAID controller may prevent access to data.
- How we work: We can emulate the original controller or build a virtual array with matching parameters, bypassing the damaged client controller when that gives a safer recovery procedure.
The server/NAS does not start and the array status is "degraded"
Supported configurations and environments
- RAID Levels: RAID 0/1/5/6/10/50/60
- NAS: Synology, QNAP, TerraMaster (and other Linux-based systems)
- Servers and arrays: Dell, HP, NetApp (RAID hardware and software)
- File systems and volumes: EXT4, XFS, Btrfs, LVM
- Logical cases: data deletion, format, configuration reset, overwrites, crashes after updating
Any unthought-out reconstruction operation of the RAID may cause data to overwrite and limit the chances of recovery. First isolate the matrix from further recording operations.
- 1. Shut down the server immediately: Disconnect the power to stop any writing processes and risk damaging subsequent drives.
- 2. Do not replace drives yourself Do not insert new disks. The array may start the rebuild process on incorrect or incomplete data.
- 3. Do not start automatic repair operations If the system asks you to verify or rebuild, do not agree.
- 4. Note the order: If possible, note which drive comes from which bay.
First, relay the crash context and the controller messages. You will receive a safe dismantling procedure and transfer diagnostic equipment.
What is the diagnosis of RAID/NAS – step by step
- Priority diagnosis - we assess the array condition and risk without destructive actions.
- Disk cloning – we work on copies so as not to worsen the damage.
- RAID virtual reconstruction - we recreate array parameters without the risk of overwriting data.
- File recovery and verification – we recover data and check the consistency of directories/files.
- Secure data transfer and report – on the client's disk or a new storage device.
SynologyQNAPTerraMasterBuffaloDellHPIBMNetAppVMwareHyper-V
Security and priority service
A failed rebuild is one of the highest-risk scenarios. If the rebuild froze, restarted or was launched with the wrong source disk, every additional write can reduce consistency. We stop destructive processes and recreate the array virtually on copies.
The most common RAID configurations
In server systems and NAS, different levels of the RAID array are used, which differ in data recording and redundancy. The most common configurations are RAID 0, RAID 1, RAID 5, RAID 6 and RAID 10.
Most RAID and NAS failures are not only "one bad disk". The lab must understand the metadata that defines the array, the condition of each member disk and the file system built on top of the volume.
What does data recovery from a RAID array look like?
Professional work with RAID starts with the diagnosis of all disks included in the matrix. Each storage device is pictured sector by sector to protect the original data from further damage.
If more drives fail than the RAID level can tolerate, recovery may require work on the damaged member disks first. The objective is to stabilise reads, image what can be imaged and reconstruct the most consistent virtual array from the available data.
RAID/NAS failure scenarios
If the problem concerns the NAS device, virtual environment or corporate infrastructure, select the nearest service below and describe the symptoms. Thanks to this technique, it will immediately verify the risk to the matrix, work copies and critical data.
- NAS data recovery – Synology, QNAP, WD and other NAS cases with volume errors, lost shares or post-update failures.
- VMware / Hyper-V / SAN – datastores, LUNs, VMFS/CSV and production environments that require work on images.
- Companies – critical server cases, accounting environments, databases and confidentiality requirements.
- Database recovery and repair – SQL, Płatnik, Optima and Subiekt files affected by storage or server failure.
- Data recovery pricing – indicative ranges and quoting rules before recovery work is approved.
- RAID crash report for diagnosis – send the controller model, number of drives, array status and last actions.
- How to safely deliver the storage device to the laboratory – packing and transport instructions after a RAID or NAS failure.
RAID 5/6/10 in a business environment - disk order and member state matter more than a fast rebuild
For company RAID/NAS cases, the safest plan is to freeze the current state before another rebuild, resync or controller change. Slot order, member-drive condition, controller messages and the last administrator action are often more important than a quick attempt to bring the volume online.
- RAID degraded - do not replace a drive or start rebuild without assessing the remaining devices.
- RAID offline - preserve drive order and controller messages before the hardware goes to diagnosis.
- Nieudany rebuild - stop further attempts because every write can change array metadata.
- Business server - identify which folders, databases or virtual machines have the highest recovery priority.
FAQ - Data recovery from RAID array
Do you run a RAID reconstruction when the data is important?
If the data is valid, do not restart without analysis of media, order and matrix parameters. First we check the arrangement to limit the risk of overwriting.
Do you need to deliver all the NAS/server, or do you need the disks?
It's usually just the disks. Sometimes we also need configuration or controller; we will indicate this after initial analysis.
What if someone clicked "initialize" or "create new volume"?
Enter device model, RAID level, disk order and stripe size. It speeds up the method.
What if someone clicked "initialize/create new volume"?
Stop operations and do not save new data to the matrix. Recoverability depends on the scale of overwrites and the state of volume metadata.
Can data be recovered after a failed RAID rebuild?
We work with, among others, the RAID0/1/5/6/10, controllers and software matrices. It determines the state of disks and matrix metadata.
How much does RAID data recovery cost?
Recoverability depends on the rebuild process, the order of disks and the scale of overwrites. The analysis starts with copies of media and history of changes.
How much does it cost to analyze RAID?
The quote depends on the level of RAID, the number of disks and the state of media. The specific scope is presented after diagnosis, before paid work.
Risk of automatic matrix restoration. How can a rebuild procedure reduce the scope of data recovery?
When business data is blocked, the useful first step is not another rebuild. It is a controlled diagnosis based on disk order, event history and member-drive condition.
Prior to the notification of RAID
Related guides about RAID failures
Before you submit a RAID or NAS case, compare the current status with the most common risk scenarios: a degraded array that still looks partly healthy and a degraded/offline array where the next action can decide the outcome.
Diskraid failure at the company — what to do
The first decisions after a matrix failure have a huge impact on subsequent recovery chances.
Read the guideRAID degraded/offline: what not to do before a lab
A practical checklist for preserving disk order, logs, metadata and parity state before another rebuild or resync attempt.
Read the guide
Describe the failure and learn the safe procedure
Tell us the array status, disk count, bay order and last action. We will explain the safest next step before recovery work begins.