First time using unraid so I decided to preclear the two drives I got after seeing it on a video I watched and doing the first pass of the preclear where it writes zeros and after its all done I get this error.

This was the first drive:

Apr 16 04:50:08 Tower kernel: blk_update_request: I/O error, dev sdb, sector 4165865472 op 0x0:(READ) flags 0x80700 phys_seg 183 prio class 0
Apr 16 04:50:08 Tower kernel: blk_update_request: I/O error, dev sdb, sector 4165867520 op 0x0:(READ) flags 0x80700 phys_seg 218 prio class 0
Apr 16 04:50:08 Tower kernel: blk_update_request: I/O error, dev sdb, sector 4165865472 op 0x0:(READ) flags 0x0 phys_seg 1 prio class 0
Apr 16 04:50:08 Tower kernel: Buffer I/O error on dev sdb, logical block 520733184, async page read
Apr 16 04:50:11 Tower preclear_disk_335747594736384A[29955]: Post-Read: dd output: dd: error reading '/dev/sdb': Input/output error

 

And this was the other:

Apr 16 04:50:08 Tower kernel: blk_update_request: I/O error, dev sdc, sector 5960269824 op 0x0:(READ) flags 0x80700 phys_seg 256 prio class 0
Apr 16 04:50:08 Tower kernel: sd 5:0:0:0: [sdc] tag#0 UNKNOWN(0x2003) Result: hostbyte=0x07 driverbyte=0x00 cmd_age=0s
Apr 16 04:50:08 Tower kernel: sd 5:0:0:0: [sdc] tag#0 CDB: opcode=0x88 88 00 00 00 00 01 63 42 88 00 00 00 08 00 00 00
Apr 16 04:50:08 Tower kernel: blk_update_request: I/O error, dev sdc, sector 5960271872 op 0x0:(READ) flags 0x80700 phys_seg 249 prio class 0
Apr 16 04:50:08 Tower kernel: blk_update_request: I/O error, dev sdc, sector 5960269824 op 0x0:(READ) flags 0x0 phys_seg 1 prio class 0
Apr 16 04:50:08 Tower kernel: Buffer I/O error on dev sdc, logical block 745033728, async page read
Apr 16 04:50:10 Tower preclear_disk_3242475555455252[17568]: Post-Read: dd output: dd: error reading '/dev/sdc': Input/output error

 

Any idea on what this may mean?

I'm running preclear version 2021.04.11

also these are external hard drives connect via usb that I would like to preclear to make sure they work before I remove the enclosure

I was running pre clear on both of them at the same time.

Please post the diagnostics: Tools -> Diagnostics.

2 hours ago, JorgeB said:

Please post the diagnostics: Tools -> Diagnostics.TOWER-preclear.disk-20210416-0714.zipTOWER-preclear.disk-20210416-0716.zip

Included the diagnostics and the pre clear log.

tower-diagnostics-20210416-1414.zip

Apr 16 04:50:08 Tower kernel: usb 4-3: USB disconnect, device number 2

USB problem, USB connections are notoriously unreliable, hence why we don't recommend using them for array or pool devices, you can try again in a different USB controller, or just remove the enclosure.

8 minutes ago, JorgeB said:

Apr 16 04:50:08 Tower kernel: usb 4-3: USB disconnect, device number 2

USB problem, USB connections are notoriously unreliable, hence why we don't recommend using them for array or pool devices, you can try again in a different USB controller, or just remove the enclosure.

Got it, thank you very much!