unraid version 7.1.4. My array: parity: 6TB disk 1: 4TB disk 2: 6TB disk 3: 2TB disk 4: 2TB disk 5: 2TB Power outage. after booting, parity check started but couldn't complete because disk 2 was failing - tens of thousands of errors in SMART data but i didn't save the SMART data. i'm quite confident it died because to double check i reinserted the original disk 2, and unraid wouldn't even boot: the bios said "port 3: bad SMART data!". it boots just fine without. i have a brand new 8TB HDD so i attempted the parity-copy operation by setting the original 6TB parity disk as disk 2, and setting the new 8TB disk as parity. the copy-parity operation keeps failing (after many hours of running) and i see these repeating errors in the logs: Oct 19 17:30:57 unkar kernel: ata8.00: status: { DRDY ERR }
Oct 19 17:30:57 unkar kernel: ata8.00: error: { UNC }
Oct 19 17:30:57 unkar kernel: ata8.00: failed command: READ FPDMA QUEUED
Oct 19 17:30:57 unkar kernel: ata8.00: cmd 60/01:a8:ef:e5:a3/00:00:0e:02:00/40 tag 21 ncq dma 512 in
Oct 19 17:30:57 unkar kernel: res 41/40:01:00:00:00/00:00:00:00:00/00 Emask 0x9 (media error)
Oct 19 17:30:57 unkar kernel: ata8.00: status: { DRDY ERR }
Oct 19 17:30:57 unkar kernel: ata8.00: error: { UNC }
Oct 19 17:30:57 unkar kernel: ata8.00: configured for UDMA/133
Oct 19 17:30:57 unkar kernel: sd 8:0:0:0: [sdh] tag#14 UNKNOWN(0x2003) Result: hostbyte=0x00 driverbyte=DRIVER_OK cmd_age=4s
Oct 19 17:30:57 unkar kernel: sd 8:0:0:0: [sdh] tag#14 Sense Key : 0x3 [current]
Oct 19 17:30:57 unkar kernel: sd 8:0:0:0: [sdh] tag#14 ASC=0x11 ASCQ=0x4
Oct 19 17:30:57 unkar kernel: sd 8:0:0:0: [sdh] tag#14 CDB: opcode=0x88 88 00 00 00 00 02 0e a3 e5 e8 00 00 00 01 00 00
Oct 19 17:30:57 unkar kernel: I/O error, dev sdh, sector 8835556840 op 0x0:(READ) flags 0x0 phys_seg 1 prio class 0I changed the SATA cables and did two more attempts at copy-parity, which resulted in the same failure with the same errors. Now, the SMART data for the 6TB parity has the following outstanding data: reallocated sector count: 531 current pending sector: 1 this drive is probably also failing because the reallocated sector count was 231 before the power outage. However, when i run the array with the original config and the original disk 2 removed, and therefore emulated, everything is fine, and i am able to copy the disk 2 data manually from the array, without any unusual behavior whatsoever. My secondary questions: i'm fairly confident my parity drive is failing, but maybe someone has a better explanation about, or solution for, this behavior. why is the hdd good enough to copy data from manually, but not enough to do a copy-parity operation, considering that both are read-only operations and should exert the same stress on the hdd? This sometimes-failing behavior is making me second-guess my diagnosis. main question: what is my best course of action to restore my array with the new 8TB HDD as the parity drive? Data is backed up and no issue, however, i'm looking for the least painful way to do this because everything is slow and restoring data will take a very long time. I understand that having lost two 6TB HDDs, my array will have a smaller capacity - this is fine. I'm thinking of just making a new config without the original disk 2, with the new 8TB HDD as the parity drive. Eventually, i'll be able to get a new drive and bring the capacity back to what it was before. i'm hoping someone has a better idea. diagnostics file attached.
unkar-diagnostics-20251020-1816.zip