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The data on the 8TB drives is most likely still intact, and the problem is related to how Windows software RAID works rather than actual data loss. Since the RAID 1 was created using Windows dynamic disks or Storage Spaces, connecting the drives through a USB dock often prevents Windows from reading the RAID metadata correctly, which is why the disks appear as invalid dynamic disks. In this situation, file recovery tools like Stellar RAID data recovery, Disk Drill are not the right solution and can lead to incomplete or messy results. The proper way to access the data is to connect at least one of the 8TB drives directly to a motherboard SATA port, even if only temporarily, so Windows can detect the disk correctly and allow the foreign dynamic disk to be imported. Once the volume comes online, the data can be copied to the new 18TB RAID. It is important not to initialize, format, convert, or attempt any repair actions on the disks, as that would overwrite the RAID metadata and put the data at risk
I had a mobo failure and pulled the 2 x 8TB drives I had in a raid 1 configuration with Windows Storage Solutions. I have built a new windows computer and installed 2 x 18TB HDDs in a raid 1 configuration. I did not reinstall the 8TB drives because i do not have room to physically mount 4 HDDs in my PC case.
I have tried to recover the data by attaching one of the 8TB drives to my new computer using an Orico usb3.0 hard drive dock. However, my computer is not recognizing either of these drives when docked and powered on. The dock works to read other sata drives and is rated for 22TB, so I don’t think the dock is bad.
How do I go about recovering this data if the computer won’t recognize the drives. Would something like Disk Drill even work for this situation. Any and all advice is appreciated. Thank you!
Edit: i wanted to add that the 8TB drives spin up when docked in the Orico, but windows does not recognize them as far as i can tell.
Edit2: Windows CAN see the drives in Disk Management, but says they are invalid dynamic disks
The problem turned out to be a damaged partition table, not a failed RAID or lost data. Three of the four drives still contained the data, but the main data partition was no longer defined in the partition table, so the array could not be assembled. One drive still had the correct layout, and copying that partition table to the other drives restored the missing partitions with the correct size and alignment. Once this was done, mdadm was able to import the RAID-5 array normally, without a rebuild. Spot-checking files showed no issues, and completing a full copy confirmed the data was intact and successfully recovered.
Update 12-27-2025: All data recovered and on another server. Thanks for all the help !
Update 12-26-2025: I was able to copy the partiton table from sda to the rest of the drives and import the array. Checking a few files across the array and there seems to be no issues yet. Started a full copy.
First please don’t say restore from backup as there is no backup. This was there backup target, that then they just started writing files to and not saving them to there computer then letting the computer backup to the nas.
This nas is a family nas that was not setup by me. But as the tec guy in the family it has turned into my proublem. They were running 4 drives in a raid 5. The nas failed and would not boot. I labled the drives and pulled them out and put them into my testing server to see what was going on. I found all 4 drives showed up but 3 out of the 4 appeared to me missing the sda3 partition that I beleave to have all the data. Is there any way I can recover that sda3 partition?
root@tempnas:~# lsblk
NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINTS
sda 8:0 0 5.5T 1 disk
├─sda1 8:1 0 517.7M 1 part
│ └─md127 9:127 0 517.7M 0 raid1
├─sda2 8:2 0 517.7M 1 part
│ └─md123 9:123 0 517.7M 0 raid1
├─sda3 8:3 0 5.4T 1 part
│ └─md124 9:124 0 0B 0 md
├─sda4 8:4 0 517.7M 1 part
│ └─md126 9:126 0 448.1M 0 raid1
└─sda5 8:5 0 8G 1 part
└─md125 9:125 0 0B 0 md
sdb 8:16 0 5.5T 0 disk
└─sdb1 8:17 0 517.7M 0 part
└─md127 9:127 0 517.7M 0 raid1
sdc 8:32 0 5.5T 0 disk
└─sdc1 8:33 0 517.7M 0 part
└─md127 9:127 0 517.7M 0 raid1
sdd 8:48 0 5.5T 0 disk
└─sdd1 8:49 0 517.7M 0 part
└─md127 9:127 0 517.7M 0 raid1
RAID 6 with 5400 RPM hard drives is chosen mainly for reliability and data protection rather than speed. The dual-parity design allows the array to withstand the failure of two drives without data loss, which is important when using large drives that can take a long time to rebuild. Slower 5400 RPM disks run cooler, use less power, and experience less mechanical stress, making them a good fit for systems that stay online all the time. Although performance is lower, especially for writes, this setup works well for backups, file storage, and long-term data retention where stability and data safety matter most.
Back up all important data from the degraded RAID first, since the remaining disk has errors and the volume is now read-only. Avoid running a bad block scan, as it could worsen the disk’s condition. Once the backup is complete, power down the NAS and replace the failing disk in slot 2 with a new, healthy disk. Power the NAS back on and rebuild the RAID 1 array using QTS. Using the original disk from slot 1 is risky due to possible read errors, so a new disk is the safer option. After the rebuild, restore any missing data from the backup.
Hi,I wanted to replace the drives in my RAID 1 array with larger ones in my TS-253 Pro, using the “replace disks one by one” method. I started by removing the disk from slot 1, waited for the beeps, and then inserted the larger replacement drive. The RAID rebuild started automatically using the disk in slot 2, but it failed after a few percent with a read I/O error (“unrecovered read error”). Since then, the RAID has been degraded. QTS said i should run a bad block scan, but I’m afraid to start it as it might harm the disk even more.
Based on recommendations I found on forums, I started backing up the data over SMB using FreeFileSync. During the backup, I received another message:
RAID group “1” is degraded. Volume: DataVol1. The group has been set to read-only. Back up all data immediately.
At the same time, FreeFileSync reported that it could not access the lock file it created:
Cannot write file “\…\sync.ffs_lock” ERROR_WRITE_PROTECT: The media is write protected. [CreateFile]
Because of this, I guess the disk currently in slot 2 may no longer match the disk that was originally in slot 1 (the one I removed).
Once I have completed the backup, how should I proceed?
Should I replace the degraded slot 2 disk with the original disk from slot 1? If I do that, will the RAID rebuild automatically from that disk? The replace disks one by one option is currently disabled. What if that disk also has issues?
Thank you in advance for any tips.
Once a Synology storage pool crashes and DSM can’t repair it, the data can’t be recovered on the NAS itself. The best option is to remove the drive, connect it to another system, and use recovery software to copy the data. The process can be slow and some files may have errors, but it allows the data to be recovered and moved to a new or rebuilt NAS.
I posted a few days ago that what I hoped would be a simple process wasn’t. More has happened since then.
To recap, I upgraded my 2 disk DS218+ from 10TB to 16TB (nominal sizes) with the recommended Synology HDDs. As I also have (had) a 2 disk DS213Air so thought I upgrade that with the 10TB HDDs. I assume that, because the first drive I fitted had a recognizable file structure, the DS218 thought there was a problem and wouldn’t let me erase the contents and add it. I swapped the smaller drive back, and followed the instructions to join it to the drive that had remained installed. All seemed well, but then the drive that hadn’t been removed threw an error and another saying that the volume/pool had crashed. Nothing I did could either fix the errors or copy the data, so I’ve had to resort to data recovery software.
I tried software to access the Linux system, but no files were recognized, and after much Googling, I came across DMDE. The free version lets you check to see if it can do what you want it to (it did) and then buy a licence, which compared to some, was quite reasonable.
I already had a 3.5″ drive caddy, so loaded the drive that hadn’t shown an error, connected it to my laptop and set the software running. It managed to find (then recover) what I believe to be everything, although it showed errors on some, which I copied off. Note that, the software let me re-try the other files (which turned out to be with errors), though needed an OK press for each, so I created an AutoHotkey script for it. 2 days later (full scan and recover), I’ve got copies of what I hope is all of the data, ready to copy onto my newly bought DS223.
Hopefully, if anyone finds themselves in a similar situation, the above will help avoid problems, or fix them.
In conclusion, recovering data from a relabeled or formatted LTO-4 tape can be difficult using standard tools like dd, because they often stop at file markers and cannot interpret the tape’s structure fully. To reliably access the data, it’s best to use specialized tape recovery software that can handle LTO-4 tapes, read data independently of the original backup software, and recover untouched sectors. This approach allows selective restoration of critical files without needing to rebuild the original backup environment.
The IBM TS4300 Tape Library (Machine Type 7DMN) delivers the reliability and automation of enterprise tape systems while remaining cost-effective for open environments. It offers high-density storage, scalable capacity, and straightforward management, making it ideal for long-term data retention and helping reduce expenses related to data center space and power consumption.
This guide covers the TS4300 Tape Library available through Lenovo. It includes important technical details, pre-sales information, key features and specifications, available components and options, and guidance on configuring the system.
The guide is intended for technical experts, sales professionals, system engineers, and IT architects who want to understand the TS4300 Tape Library and evaluate its suitability for IT deployments.
The issue you’re running into is common with LTO tapes, especially when they’ve been relabeled or partially overwritten by software like Archiware P5. LTO tapes don’t fully erase old data when relabeling—only the catalog or tape header is updated—so there is often recoverable data in untouched sectors. Tools like dd can hit a file marker and stop because they don’t interpret the tape format or handle multiple filemarks correctly, which is why your attempt failed.
For this scenario, the most reliable approach is to use a dedicated tape recovery solution. Stellar Data Recovery for Tape is specifically designed for this:
It can read LTO-4 and higher tapes directly.
It bypasses the need for the original backup software or catalog.
It recovers data from untouched sectors even if the tape has been relabeled.
It allows selective recovery, so you can pull only the files you need.
Using Stellar Data Recovery for Tape, you can safely recover the data without relying on dd or rebuilding the original backup environment, which is often the only practical method when the original software isn’t an option.
In short: for a formatted or relabeled LTO-4 tape where dd fails, Stellar Data Recovery for Tape is the most effective solution.
Hello,
I’m looking for advice on software that can read data from a formatted LTO-4 tape and recover the data stored on it.
The tape was originally written using Archware P5. In our experience, relabeling a tape in P5 typically replaces the tape name but does not fully erase the existing data, which means some sectors may still be intact and readable.
I attempted to read the tape using the dd tool, but it stops after a few seconds with a message indicating that a file marker has been reached.
Can anyone suggest a way to work around this issue, or recommend software that can read and recover data from an LTO-4 tape under these circumstances?
Hi there, I have a raid 5 of 3 disks (4th one is broken). I wanted to recover the data but I can’t find a completely free raid recovery software. If anyone knows where to download one tell me or if your nice enough just give me a raid recovery key.