[SOLVED]Yet ANOTHER...'Replacing Drives' Question

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UGH! I am soo damn mad at myself! 🤬🤬🤬🤬🤬


Here I am...just steadily going about, my monkey's work. Copy drive...wait hours; format drive...copy drive...wait hours.


Monday night, I checked the copy...from disk5 to disk4. 4 more hours at bedtime. Great...I have a FULL day tomorrow. I'll get up in the morning; 5 to 4 will be done. Format 5, copy disk7 to disk5 (remember...disk6 was already copied to disk1, and will just be coming out when we're done); and it can get started on its hours, while I'm out ALL day.


I was in a hurry; no coffee...and so I kept reminding myself: FORMAT 5, COPY 7!!


I go to do the copy; and realize I f@#king formatted disk7.




I punched myself in the head, but had to go. The only thing, that kept it from ruining my day completely...is the small hope, that it might be recoverable. I kind of told myself...that's what RAID and Parity is all about, right; protection for 1 disk? Trust me...I'm hoping for the best, but am realistically expecting the worst.


So...can I recover, what I formatted from disk7??

Edited by CDLehner
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1 hour ago, CDLehner said:

So...can I recover, what I formatted from disk7??

Not likely unless you have a backup of it somewhere outside the array.


Parity is not a backup.  It has no actual data on it and is just a bit calculation that helps recover a failed disk (also requires all other data disks to be readable and accessible). A format operation also updates parity so parity now thinks disk 7 contains nothing but a file system.

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A format command simply rewrites the control structures, and does not overwrite the actual data blocks.  Since the disk was in reiserfs format then you might just be able to recover much of the data by running reiserfsck against it with appropriate parameters   Cannot hurt to try at this stage.   I think the relevant command would be:

reiserfsck --scan-whole-partition --rebuild-tree /dev/md7

but you might want to see what someone else thinks.     Note that this command would take hours to run so do not expect any quick results.


another possibility might be disk recovery software such as UFS Explorer.

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Thanks itimpi. I am waiting to see what others have to weigh-in, before doing something.


In other words, I'm happy to run this command...


1 hour ago, itimpi said:
reiserfsck --scan-whole-partition --rebuild-tree /dev/md7


and/or any tool, that might help. Just waiting, before it's even more "too-late" to turn back.

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Someone lent me a copy, of Stellar Data Recovery Technician 10.2


I'm just a little confused, about how to go about the recovery. And while I know those here, aren't neccesssarily here to give advice about Stellar per se; I'm looking at their FAQ...




...and I'm wondering: if this is something that needs to be done, "inside" the array; or can I do something as simple, as drop that drive...into a SATA/USB dock, and recover it?


This is all, new territory for me.

Edited by CDLehner
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5 hours ago, CDLehner said:

The only thing, that kept it from ruining my day completely...is the small hope, that it might be recoverable. I kind of told myself...that's what RAID and Parity is all about, right; protection for 1 disk?

Format is a write operation. It writes an empty filesystem to the disk. Unraid treats that write operation exactly as it does any other, by updating parity. So after format, the only thing parity can rebuild is an empty filesystem.


Unraid IS NOT RAID. I doubt any sort of RAID recovery tools will have any idea what to do with Unraid.


UFS Explorer is often mentioned here. There were a couple of others mentioned on some thread, I'll see if I can track that down.


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2 hours ago, CDLehner said:

Just waiting, before it's even more "too-late" to turn back.

How valuable is this deleted data, cost wise? The proper way to do this sort of recovery is clone the drive bit for bit to another disk, same exact size or larger, then run the recovery tools on the clone, one at a time to see which one gets the best result. That way you keep the original drive intact until it's obvious you can't do any better.


I haven't been following this thread very closely, but if you have another good 3TB that has no valuable data on it you could use it for the recovery process.


Professional recovery tools generally don't write to the disk being recovered, so you need another destination disk or free space besides the clone to write the recovered files.


The reiserfs rebuild tree generally gets very good if not perfect results, but it DOES write to the target drive, so if the data is very important, you need to run it on a cloned copy, not the original.


This sort of thing is very time intensive to get right, so you need to decide now whether the data is worth it.

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So...let me say this:


^ I do have an extra 3T drive...if that's what's needed for "proper" recovery

^ I've said from the start, time wasn't that big a factor (though it is taking much longer than anticipated...due to my fault entirely) 


22 minutes ago, JonathanM said:

This sort of thing is very time intensive to get right, so you need to decide now whether the data is worth it.


^ And I think this is the thing I have to wrestle with; and...maybe all of you, keep mission-critical files on your servers...but I just have dumb movies and music on mine. Now, I say "dumb"...tongue in cheek, because OT1H; music and movies, aren't family heirlooms and/or one-of-a-kind files. OTOH...how many will I lose, how many can be replaced; and when will I even know they're destroyed???


For example: let's say I have 20,000 albums, ripped and stored. By f**cking up that ONE drive; will I lose 500...or will some part, of 18,000 be lost? Let's say...if I knew I'd lost it, right now; I could replace it. But...maybe I don't go to listen to that album...or watch that movie; for a year (literally, one time...I was watching a movie; Home Theater, people over...and we didn't get, like the last 15 minutes of the movie...the climax! Because of a likely file/disk corruption). Maybe, once I discover it; now it's not recoverable.


No...I don't still have, ALL the media I've ripped...over 15 years?? Yes, they're just music and movies; but they're my music and movies. The music is more precious. If it turns out, True Lies got corrupted/lost; I go on eBay, buy a used copy. Rip, store, etc. But if I go to listen, to the HiRes FLAC file...of The Koln Concert; that I paid $20 to download...and that's now compromised. That's another story 🤷‍♂️


This is all, mostly rhetorical. This is the decision I have to make. Let's put it this way: if someone has done it...knows how to do it; if it's just time-consuming, and the likelihood of success...is "high". Sure...why the hell not. If not: if it's time-consuming, and a pain-in-the-a$$, and a moon-shot to boot; I'll just have to accept...what's gone is gone. Not enough time, left in this life, to listen to 20,000 (or whatever it is...lost/stopped counting) albums anyway.

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Little 'ole me; teach you guys something. J/K; I realize, you have to do something dumb like this...to begin with...to even need to try this kind of recovery.


I did a quick search of YT, about Stellar Data Recovery...and this was the 1st hit. I think it's fated: it was also a 3T drive...and just "dumb" files, like mine.



Ordered a double-dock, that's due today (Thursday); and we'll have a run. WTH; can't get any worse, right?

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One of the "issues" I'm anticipating...is with disk formats.


Of course, I'll re-watch the above video...in greater detail, as I'm in the midst of actually trying it; but he did say something about...it not being able to recognize drives, because they weren't formatted...but to format them, would mean to lose data.


IDK...something like that; and it was explained, because of a feature Stellar does have...that allows it to find drives, that aren't of a format Windows recognizes. I'm just not sure, what it will do with reiserrf and XFS.

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^ Oh boy; now I'm confused again (go figure, right?)


- So...I can/should, go ahead and try Stellar; just doesn't seem like it'll likely work?


- FTR...I think I might as well use disk5, as my "clone"; since it was 5 that was supposed to get formatted....in order to have 7 copied to it to begin with. Let's say, Stellar does see these drives; 5 is reiserfs and 7 is XFS. I think...whether it is Stellar, and/or cloning...and/or; these need to be on the same format? If so...make 5 XFS, before I start; or re-format 7 back to reiserfs (and would/n't that make any kind of recovery, even less likely)?


- And if none of the above, is really much of an option; and I decide on this...

On 2/8/2023 at 11:20 AM, itimpi said:
reiserfsck --scan-whole-partition --rebuild-tree /dev/md7


I leave disk7, on XFS...and run this command?

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1 hour ago, CDLehner said:

I'm confused again

A few confused things in this post, mostly around filesystems. Rather than quote the confusion I will just see if I can explain things.


From what I read on Stellar, it might be able to restore a partition table whatever the filesystem. But that isn't going to mean it works with the filesystem itself. The filesystems it specifically mentions are all Windows filesystems. And we don't need it to restore a partition table since that is already there, it's just that the partition contains an empty (formatted) filesystem.


Cloning a disk is kind of like rebuilding. It will produce a bit-for-bit copy of the disk, and so, it will have the same filesystem as the original, since all those bits ARE the filesystem with all its files.



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- I think I understand. While Stellar might see, the wrongly formatted disk…in XFS; it likely can’t restore, to anything other than a Windows-based formatted disk (and FTR…if that’s true…that is kinda what I was thinking)?

So…if I run reiserfsck; I don’t run it against a clone of 7, right?


reiserfsck —scan-whole-partition —rebuild-tree/dev/md7


is “right against” 7 itself, yes?

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^ OK…


- how do you clone a drive, in unRAID; or will a CLONE…like in the dock on Windows…just be bit-for-bit perfect, including not caring about XFS, and re-creating XFS (or reiserfs…doesn’t matter, if we get the data back and get to “start over”)


- and…do we then put the clone in, make IT disk7 (while keeping the ORIGINAL disk7 out of the mix)…and try the reiserfsck?

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  • CDLehner changed the title to [SOLVED]Yet ANOTHER...'Replacing Drives' Question

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