- Synology RAID hard drive defective after power failure
- RAID 1 causes IT emergency – how RecoveryLab in Hanover recovered all data
At an advertising technology company in Hanover, a gradual failure of both hard drives in the RAID 1 system led to complete data loss – and thus to the standstill of all ongoing customer projects. Only through specialised analysis and data recovery at the RecoveryLab laboratory was it possible to completely reconstruct the sensitive production data from Hanover.
The fatal mistake: ‘One drive is still enough’
A Synology DS218+ NAS with two Seagate IronWolf 4 TB HDDs, operated in RAID 1 mirror mode, was used. The configuration suggested security: if one hard drive fails, the other takes over – without any data being lost. When mechanical read errors caused by a defective read/write head led to the gradual failure of the first hard drive, the system displayed warnings in the interface. However, as no active notifications had been configured and the data was still available, the error went undetected. From then on, the system ran exclusively on the second hard drive. As the data was still available, operations appeared to be running smoothly.
It was not until weeks later, in the middle of operation, that the second hard drive also failed – this time due to an electronic defect in the control electronics. The NAS system only showed red status LEDs and access was completely blocked.
Data recovery in a clean room – with two damaged disks
The affected drives were sent to RecoveryLab in Hanover. The diagnosis in the in-house cleanroom laboratory revealed that the first hard drive had mechanical damage caused by defective read/write heads, which meant that user data could no longer be accessed. The second hard drive then suffered electronic damage in the form of a circuit board fault, so that the device no longer initialised and the S.M.A.R.T. values could no longer be read.
In the laboratory, the mechanically damaged hard drive was first opened and the defective read/write heads replaced. A complete image of the disk surface could then be created. To check the integrity of critical file structures and back up additional sectors, the second hard drive was also read out via a customised controller interface.
Result: 100% of the project data was recovered
Within a few working days, all project-related data – including customer templates, graphics, invoices and layouts – was completely restored and transferred to a new, external storage medium.
‘We had long believed that RAID 1 was sufficient to prevent data loss,’ says Mr M., IT administrator at the advertising technology company. ‘Now we know that this is only true as long as you notice when a disk fails. Without a real backup, you quickly reach your limit – and then you need professionals.’
About RecoveryLab in Hanover
The RecoveryLab branch in Hanover is part of the Germany-wide network for data recovery and IT forensics. The team supports companies, public institutions and private individuals in recovering data after physical, logical or electronic defects. The recovery is carried out under professional laboratory conditions – including clean room technology for processing opened hard drives and individual analysis procedures at block and file system level.
