Hi All,

Just migrating 2x 4tb WD Red drives from Synology to Unraid, one drive seems to have precleared fine, with one drive starting the "pre-read" phase but never gets past 0% (sits on 0mb/s). SMART data says the drive is fine, so wondering if there's anything I can try?

I've tried different SATA ports, but get the same issues.

Thank you!

preclear_disk_WD-WCC7K4ETKFN3_950518.txt

Attach Diagnostics ZIP to your NEXT post in this thread.

Sorry please find attached diagnostics

nas-diagnostics-20260102-1502.zip

Check connections

I've checked the connections, and tried to use the same slot where the other disc did the pre clear, but still having no luck, seems to read in my main tab, but never progresses with the pre clear

Log is full of ATA erros for ATA6:

Dec 30 10:34:02 BAMNAS kernel: ata6.00: status: { DRDY ERR }

Dec 30 10:34:02 BAMNAS kernel: ata6.00: error: { ABRT }

Dec 30 10:34:02 BAMNAS kernel: ata6.00: configured for UDMA/33

Dec 30 10:34:02 BAMNAS kernel: ata6: EH complete

Dec 30 10:34:02 BAMNAS kernel: ata6.00: exception Emask 0x0 SAct 0x0 SErr 0x0 action 0x0

Dec 30 10:34:02 BAMNAS kernel: ata6.00: irq_stat 0x40000001

Dec 30 10:34:02 BAMNAS kernel: ata6.00: failed command: READ DMA

Dec 30 10:34:02 BAMNAS kernel: ata6.00: cmd c8/00:08:00:00:00/00:00:00:00:00/e0 tag 11 dma 4096 in

Dec 30 10:34:02 BAMNAS kernel: res 51/04:08:00:00:00/00:00:00:00:00/e0 Emask 0x1 (device error)

Replace both cables for that disk, os swap with another one and see where the issue follows.