After replacing a smaller drive with this and the rebuild successful, I spun down all disks (I am tracking down a problem where they are not automatically), the new disk spun up and I received one disk error in the Unraid dashboard - none since. SMART scan is OK and I am in the process of doing an extended test.

Jan 2 09:47:50 Tower kernel: I/O error, dev sdr, sector 6464106752 op 0x0:(READ) flags 0x0 phys_seg 1 prio class 0

Jan 2 09:47:50 Tower kernel: md: disk6 read error, sector=6464106688

I am wondering whether to worry about this (I have ordered a replacement just in case but might just add the new disk to the aray).

Edited January 3Jan 3 by topherino

Please post the diagnostics.

Earlier today the disk spun back up with another 32 errors.

The extended self test complted without error.

One thing to note is I have all disks in the array connected to two LSI 9207-8i, which do not support 4Kn "officially", and this disk is the only 4Kn. however the disk rebuilt OK and there have been over 10 million sucessful reads since. Could this be the reason why I am getting sector read errors?

I have attached diagnostics.

tower-diagnostics-20260104-1908.zip

Edited January 4Jan 4 by topherino

I think this is solved - I have connected this 4Kn drive to the motherboard directly, and no more errors after multiple spin downs.

Suspect this is because it was connected to the legacy 9207-8i which has known issues with 4Kn drives.

Edited January 4Jan 4 by topherino