Unfortunately I had another thing trip the relay at home taking my server offline. When it restarted, one disk is reporting 3000+ errors and unRAID disabled it and says it's contents is emulated.

I'm not able to get a SMART status from it, as it just says:

Smartctl open device: /dev/sdf failed: INQUIRY failed

When selecting the disk, it says:

Partition format: MBR read error

The syslog keeps spamming lines like these:

Dec 22 09:57:36 Opportunity kernel: sd 5:0:0:0: [sdf] tag#10 UNKNOWN(0x2003) Result: hostbyte=0x04 driverbyte=DRIVER_OK cmd_age=0s

Dec 22 09:57:36 Opportunity kernel: sd 5:0:0:0: [sdf] tag#10 CDB: opcode=0x88 88 00 00 00 00 00 00 00 00 47 00 00 00 01 00 00

Dec 22 09:57:36 Opportunity kernel: I/O error, dev sdf, sector 71 op 0x0:(READ) flags 0x0 phys_seg 1 prio class 2

Dec 22 09:57:36 Opportunity kernel: Buffer I/O error on dev sdf1, logical block 7, async page read

I'm wondering if it's "just" a filesystem error, and if I should try to format the disk and rebuild or if I should just replace the disk. What would you suggest?

Please post the diagnostics.

Sorry - forgot about that when I posted. It's attached.

I just picked up a replacement just in case - didn't wanna risk needing a disk over the holidays, when stores are closed.

opportunity-diagnostics-20251222-0957.zip

It's not logged as a disk problem, but the disk dropped offline, so there' no SMART, check/replace both cables and post new diags after array start.

Finally found another cable - now the SMART is there, but with read errors. :-/

opportunity-diagnostics-20251223-1251.zip

Edited December 23, 2025Dec 23 by RazziaDK

Yep, doesn't look good, and the short SMART test failed, disk needs to be replaced.