Hi all, I got a situation as below.
Basically I want to know if I should be confident enough to use the disk in question going forward, at its current exact location and SATA slot?
My plan was to shrink the array, unassign disk10, and use it as unassigned device.

1. During non-correct parity check,  disk10, /dev/sdu, reported rapid UDMA CRC errors (going from 0 to 3000+ count).
2. Turned off system, replaced SATA cable (actually it's a 4-ways branch-out cable from a jbod pcie controller, the order is preserved, i.e. the "3rd cable").
3. Parity check finished without error, and without new UDMA CRC error.
4. Disk10 content emptied without error, empty shared folder deleted.

5. To follow the procedure to 'Shrink array', https://wiki.unraid.net/Shrink_array#The_.22Clear_Drive_Then_Remove_Drive.22_Method
    created clear-me directory, then started the clear_array_drive script. (I've done this procedure multiple times in the past when shrinking my array).
6. Syslog reported rapidly a bunch of write error on disk10, and unraid subsequently disabled disk10.
7. Stopped the clear_array_drive script, rebooted the system, did New Config, unassigned disk10.
8. Rebuild parity with remaining 9 disks, no error.
9.  Preclear sdu (formerly disk10), it started with a few lines of write errors logged on syslog, but no further error for the next 14+hours until preclear finished with successful message.
10. Did short smart test, and then extended smart test on sdu, both passed.
11. On Unassigned Devices, formatted sdu with XFS, did few GBs copy test, no error reported.

I intend to use this disk on unassigned devices as 'staging disk' for big-size content work, should I be worried?
Thank you beforehand.
 

Edited November 23, 20205 yr by ldrax
more info

Diagnostics?

I need to find a way to get a cleaner diagnostics. Currently a bunch of DIY scripts are contributing to syslog messages that are not exactly public.
I can post the 'Disk Log information' if that helps.

This is the 'Disk Log Information' from unassigned devices menu.
Note that this log only after the Reboot described at point 7) above.

The errors at the Nov 21 23:26 - 23:27 was just after the Preclear started (point 9 above).
 

sdu-log.txt

Edited November 23, 20205 yr by ldrax

Post the SMART report for the disk.

Here it is.

SMART-sdu.txt

I probably should do the Preclear again, because for reason that escaped me, I opted to 'Skip pre-read' and 'Skip post-read' when I started the preclear that night.