QNAP TS-219P+ supports two RAID types, RAID1 and RAID0, as well as JBOD, which is sometimes referred to as linear RAID, but technically it isn’t a RAID at all. In the end, redundancy in this NAS is only achieved by using a mirrored RAID. But if one of the disks fails in either RAID0 or JBOD, a part of the information is bound to be lost.
I have asituation when the NAS is broken; all the files are still on its disks but it’s impossible to retrieve them unless use a specialized software tool.
The matter is that a NAS storage device uses its own operating system which builds the RAID in a certain way and then writes data to its disks. Even when the hard disks are connected to another storage device or computer, their condition cannot be restored.
For example, when the disks are connected to a Windows computer, I see some partitions with an unrecognized file system; another possible case is that the operating system will suggest initializing them in the Disk Management app – which is going to erase all the data still remaining on the disks.
In a Linux operating system, the disk partitions will be displayed as Linux RAID, and the option to mount is unavailable.
So, to retrieve the information from the hard disks, I need a special tool to rebuild the RAID system and restore access to the files which are stored inside the disk array.
Yes, there are various programs for data recovery from RAID arrays. But I need feedback from those who have experience using such tools. Recommend programs that you have had experience using, and what are your impressions of them.