RN 316 - Raid 5 config, Data Volume Dead

StephenB 

Data is all personal/unique and important enough to attempt recovery. Not the end of the world if the data is lost, but valuable enough to try. My thinking is spend a little to do an initial but safe evaluation of my drives. If it does look possible for me to proceed with data recovery, pause and assess if I continue on my own or consult with a professional based on their price estimates.

I was unable to pull the latest logs from the RN 316 admin dashboard. Although I was able to navigate around the dashboard, each time I tried to download the logs, I was presented with a generic web service error. I don’t recall the error…I want to say it was a 503 error code. The web service was not able to respond to my request to download the logs.

Question: are you familiar enough with the internals of how RN 316 stores and manages its log? My thinking is it should have its own internal storage or memory to collect logs (and not use the hdd that make up the raid array). If so, I could remove and label all drives, power up the RN and connect to it and attempt to either download the logs from the web portal or ssh in and access the logs from the terminal. What do you think? Is this worth pursuing?

I do however, have logs from a day earlier, prior to the failure of the NAS. It’s important to note from the logs that disk3 has multiple warning reports.

Yes, the resync happened on its own. A scheduled scrub was running, which caused Disk2 to “lose sync” and that triggered the resync to automatically occur. This is what lead to Disk3s reported failure and then data volume dying.

Question: since the NAS reported that disk2 was offline and in a resync state, does this imply that any data that was on this disk to preserve the data volume has been lost or become invalid? It had only been resyncing for a 3 hours of the 27 hours it estimated for completion. I’m asking b/c I want to know if I can even consider disk2 as a candidate for restoring the data from the NAS.

I don’t have experience in data recovery. I am very comfortable working in Linux environment and running command lines. I’m not experienced with mdadm or btrf so i would need to study up on those filesystems.

The total volume size was at 18TB. I do see 20+ TB drives in the market that are reasonably priced. I prefer to proceed with your suggestion for cloning each drive as an image and store them on a single hard drive before attempting the data recovery process. At least I will then have images of each drive saved and can then decide how to proceed with data recovery using the original hard drives.

Question:

1. You suggested I connect each drive to a PC running Western Digitals dashboard utility to check the status of the drive. Are you referring to this https://support-en.wd.com/app/answers/detailweb/a_id/31759/~/download%2C-install%2C-test-drive-and-update-firmware-using-western-digital
2. Assuming tool recognizes the connected drive from the NAS, what should I be looking for?
3. I understand I can run various tests, but I’m not sure I want to run them at the risk of stressing the drives further.

Here’s my proposed plan. Please let me know what you think:

1. Purchase a 20TB+ hard drive for storing images of each cloned drive. Even if data recovery is impossible, I can utilize this drive for other purposes so I’m willing to make this expense in the beginning.
2. Connect disk3 (drive that was in a FAILED state) to a PC running WD dashboard.
3. If the drive is recognized by the dashboard, proceed with cloning the drive.
4. Question: I’m learning that ddrescue for Linux is the best tool for cloning. Assuming I get this far, I’d need to reboot the machine and open my Linux environment. Is this the right tool and env to use for cloning? Alternatively, I can setup ddrescue-gui in advance to be prepared to do a clone in a windows environment.

Thank you!