sneakinhysteria

Unraid Stable 7.2.3 on N5105 Hi all, just wanted to flag an odd experience I had as this could potentially be a data loss scenario for some. I ran a 1 parity (12GB WD HDD)/1 data (10TB WD HDD) array for 2 years. The 12TB was a warranty replacement for another identical 10TB HDD. The failing HD was my parity, so the 12TB also became the new parity. All good so far. I now needed more storage and wanted to add another 12TB to the data pool. I bought a Seagate 12TB HDD, unfortunately it turned out to be ever so slightly bigger than the existing WD 12TB parity drive so I needed to create a new config. I did by using existing assignments and without ticking the valid parity box. The array came up and started to sync/rebuild parity. There was no formatting prompt of any kind for the old parity drive. I now had 22TB storage as expected. Weirdly, I suddenly also had 16TB used. The old 10TB had 8.14TB as before, the added 12TB HDD (previously my parity) had 8.13TB used. I browsed the drives (both XFS) and it turned out both had seemingly identical data on them, including time stamps from 3 days ago. The files also looked valid (as far as I could tell by looking into file headers). Obviously, this is impossible as the drive can't have magically replicated within seconds. But it was cler that Unraid read this content as being on the former parity drive. I can't explain why there was a 10GB difference between both. But other than that they seemed identical. It's impossible that I confused drives as they all are different and I triple-checked everything. I ended up removing the old parity WD 12TB drive from the array and am now rebuilding the parity on the Seagate 12TB from the actual old 10TB WD drive only. I formatted the old 12TB WD parity drive in unassigned devices as XFS and will add it back later when the parity sync is completed. But this is very confusing and rather worrying. A former parity drive should nto magically appear as it had 8TB of mirrored data n it.