Re: Replacing a drive caused 100% data loss (but not share/user structure loss) WTF ?

drsox · ‎2015-08-03

I'm a long time ReadyNAS user (since the Infrant days). Now I have 2x 5 drive ProPioneers.

One of the drives (drive 1) suddenly failed - lots of non-recoverable errors. So I took my spare drive and used it to replace the failed one. (Silly me as I should have made a backup using the 4 good drives. Fortunately I have backup from last week but not from today).

The drive set started to rebuild BUT the web page showed that drives 3, 4 and 5 were marked as DEAD (WTF?) even though RAIDar showed 3,4 and 5 as green. Drive 2 showed as resynching but with no data as content (!). There should have been 7TB of data. I could also not access any data but the shares and users were shown in CIFS and on the web page, but all shares and users had 0 data.

After 4 hours drives 1 and 2 were synched and the set was fully redundent but with only 2768GB of space (only 1 drive). Drives 3,4 and 5 were green but obviously weren't visible to the system. So all the data is missing . What do I do.

Up to now I have had 100% confidence in ReadyNAS - this has persisted for 8 years, until now.

StephenB · ‎2015-08-03

Well, you could contact support and get a data recovery contract.

Or restore from backup, and reconstruct any missing files.

drsox · ‎2015-08-03

Thanks, but not helpful. What caused this ? Why has the previous 100% reliable RAIDiator S/W failed or is this a H/W failure.

What will happen if I reinstall the OS ?

What other options are there ?

StephenB · ‎2015-08-03

I think someone from Netgear would need to do a deep dive into the logs to figure out what happened.

drsox · ‎2015-08-03

Yes, but is the data lost. If it is I can move on. If not then I can try to recover it.

Drive 1 is new. The old Drive 1 has been reformatted.

Drive 2 has been synched to Drive 1 so all the old stuff has been overwritten.

Drive 3

Drive 4

Drive 5 are untouched, so still have the old stuff on them

Only XRAID 1 was in use, so my guess is that the data is lost as more than 1 drive has "failed"

StephenB · ‎2015-08-03

@drsox wrote:

Yes, but is the data lost. If it is I can move on. If not then I can try to recover it.

Drive 1 is new. The old Drive 1 has been reformatted.

Drive 2 has been synched to Drive 1 so all the old stuff has been overwritten.

Drive 3

Drive 4

Drive 5 are untouched, so still have the old stuff on them

Only XRAID 1 was in use, so my guess is that the data is lost as more than 1 drive has "failed"

I think you mean XRAID single redundancy (XRAID-2 is something else - XRAID-1 didn't do vertical expansion, XRAID-2 does).

However, my guess is the same as yours. You could pursue with Netgear just in case, but I think the odds are against you.

mdgm-ntgr · ‎2015-08-03

Please send in the logs (see the Sending Logs link in my wig).

It does sound like a data recovery situation to me.

drsox · ‎2015-08-03

Thanks. I'll do this at the end of the week as I'm off for a few days.

mangrove · ‎2015-08-04

As I understand it the scenario is this:

1) 5-disk system in RAID5

2) Old disk 1 failed, now disk 1 and 2 got synced together in a RAID1

3) Disks 3, 4, 5 are still unaffected and contains 3/5 of the old RAID5 set

I guess you are running OS4. The information below is not applicable to OS6, as far as I know.

In this scenario you can use the remaining three disks and the OLD disk 1 together with RAID reconstruction software to get to the data written since your last backup. Even if that disk has some SMART errors, as long as it's not dropping out it can be read. Remember you only have to get the data written since the last backup. The software will "compensate" for the missing disk 2, reconstructing parity on-the-fly.

You will need a computer with 4 free SATA ports (or USB adapters, not recommended!) and RAID reconstruction software. Personally I have used R-Studio with great success.

mangrove · ‎2015-08-04

Missed "old drive 1 has been reformatted". This probably doesn't matter if it was a quick format or done in an old XP computer, I think R-Studio can work with that anyway. If it was a full format in Windows Vista or later, or another form of drive zeroing (format taking several hours), it is unfortunately impossible to get back the data.

Sorry! But the lesson here is: always leave the maximum number of options open for data recovery until full redundancy is established again and the data set is tested.