November 14, 20241 yr Hi, I have a 12 drive array. 1 parity (10 tb), 1 cache (2 tb), ane a 10 drives for storage. Back in Jan or Feb i lost a 1tb drive out of the array and removed it from the array. It still shows as unassigned (it's drive 9 for reference), but hasn't been in for months. I have my parity check set to run weekly. It takes about 20+hrs but, i figured better safe than sorry. Lastbight, I got some alerts and upon looking into them, realized drive 2 was showing as missing. I found the drive physically, and it will spin up but doesn't register as being present. The parity drive is a 10tb drive, the drive that is missing g is 10tb. My question is, can i somehow restore the array by replacing the bad 10tb drive and letting ubraid so it's thing? The 1tb drive has been out and the parity has been checked and , I believe even rebuilt, more than once since that drive was removed. Any help would be greatly appreciated!
November 14, 20241 yr If I understood correctly and you have two invalid disks with singe parity you won't be able to replace them, please post the diagnostics.
November 14, 20241 yr Author Well, that's what I'm trying to sort out. The first drive died months ago and parity was rebuilt many times. It was checked weekly as well. I'm not sure that the 1tb drive is even in the parity data anymore. (It was empty when it failed) I was just wondering if I could create a new co fig, remove that 1tb drive from the array properly, the. Rebuild using a new 10tb drive to replace the one that died lastnight? (Any info from the server I have to get when near it later)
November 14, 20241 yr 14 minutes ago, Weatherby said: I was just wondering if I could create a new co fig, remove that 1tb drive from the array properly, the. Rebuild using a new 10tb drive to replace the one that died lastnight? Nope, that's not possible.
November 14, 20241 yr You can do a new config without both missing disks and re-sync parity, any data on those disks will be lost.
November 14, 20241 yr Author Ok, so, unless i can recover data off the 10tb that doesn't register, I'm looking at data loss, correct? But if I could recover that data and clone it to a new hdd, the parity check would restore?
November 14, 20241 yr Author I was just thinking, and I know what you said, but hypothetically: If I put in a new 10tb hdd and removed the 1tb drive then re-sync parity, worst that would happen is id still loose both disks data...but best might be to recover some of the 10tb feom parity to the new hdd? Either way, I need a new 10tb drive.
November 14, 20241 yr Parity contains none of your data. Parity just contains parity bits that allow a missing disk to be calculated from all the other disks. The critical point here is ALL the OTHER disks. Parity by itself can recover nothing. https://docs.unraid.net/unraid-os/overview/nas/#parity-protected-array If you have been running single parity with a missing disk for these many months, then you had no redundancy when the other disk failed. 14 minutes ago, Weatherby said: If I put in a new 10tb hdd and removed the 1tb drive then re-sync parity then parity will agree with the contents of the new 10TB drive, which would be empty.
November 14, 20241 yr 1 minute ago, trurl said: If you have been running single parity with a missing disk for these many months, then you had no redundancy when the other disk failed. 3 hours ago, Weatherby said: I have my parity check set to run weekly. It takes about 20+hrs but, i figured better safe than sorry. Sorry not safe when a disk is missing. If a disk was missing then it was only doing a read check, which just tests that it can read all of the other disks. It can't check single parity when a disk is missing. 19 minutes ago, Weatherby said: put in a new 10tb hdd and removed the 1tb drive then re-sync parity New Config / Resync Parity will get your array stable again. Maybe the original 10TB can be read as an Unassigned Device to copy its data. But we can't really give good recommendations without Diagnostics that includes the failed disk.
November 14, 20241 yr Author Ok, ill power up the server when I get off work and pull the diagnostics. Also, tha k you for the parity explanation. I guess I was thinking traditional raid with parity.
November 14, 20241 yr Author Oh, one other thing: SHOULD I be able to get the bad 10tb drive to register to where I can pull data off, is there any specific things I need to do to clone it to a other 10tb drive to salvage the data? Or will any clone software do the trick? (I've never tried it with unraid)
November 14, 20241 yr You can use ddrescue: https://forums.unraid.net/topic/46802-faq-for-unraid-v6/?do=findComment&comment=525075
November 14, 20241 yr Author Ok, here's the diagnostic zip from the unraid server with the bad drive attached. diagnostics-20241114-1628.zip
November 15, 20241 yr Disk2 missing, disk9 disabled, don't see either one attached. Try to connect disk2 again.
November 15, 20241 yr Author That's the problem: THe drive is not detected at all. It's connected. 9 was removed months ago. I started trying to remove it from the array, and set it to unassigned, but it always showed up as unassigned. Drive 2 is the one that just 'disappeared' from the system on me. It's connected to the unraid box for that diagnostic, it's even spinning. I tried an external caddy via usb, no luck even on a windows box. It spins up but no data connection is made.
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