Hi, i'm new to unraid and am having problems preclearing some hard drives.
The server has 18x 16tb exos drives - on the 6 Sata connectors on the mother board and
12 Sata connectors using using 2x M.2 To SATA 3.0 Riser Cards. I have precleared 15 of the
hard drives with no problems.
The last 3 are on the 2nd M.2 To SATA 3.0 Riser Card. Two of the six Sata hard drived on the
riser card successfully preceared without problems.
I replaced the sata power and data cables - this appeared to make a difference. This server
was unintentionally shutdown during the preclear operation. After this 3 of the drives
have udma errors in excess of 15000-20000 with read rates <50MB/s. I have tried to restart
the preclear operation but the more errors occur.
Does anyone have a suggestion to how i can preclear the 3 hard drives?

 

 

That suggests a SATA cable problem, o a bad controller, try connecting those disks to the onboard SATA, if it's the same, it's likely the cables.

Thanks, for the reply

I've shutdown Unraid and unplugged 2 of the onboard Sata  connectors, and then plugged in 2 of the sata connectors from the 2nd M.2 Sata 3.0 riser card which are giving udma crc errors.

Restarted Unraid and only 14 of the 18 hard drives appeared in the unassigned disk list - the 2 problematic drives did not appear on the list - going to unassigned plugin did not located them. 4 Drives appeared in the Historical Devices list of the main Unraid Tab -  corresponding to the 2 disconnected drives and the 2 newly connected problematic drives. Removed the problematic drives from the Historical Devices list , rebooted and executed the unassigned plugin.  The 2 problematic drives do not appear on the unassigned devices.

 

Do i need to remove all the historical devices in order for the problematic drives to appear on the unassigned devices list?

 

16 minutes ago, halfmoon said:

Do i need to remove all the historical devices in order for the problematic drives to appear on the unassigned devices list?

You do not have to do anything to the Historical Drives section.   That is where UD puts entries it previously knew about but currently thinks are not present on the server.   The fact the drives are not appearing means they are not showing up at the Linux level.   Whatever the 4 ‘missing’ drives are attached to is therefore probably not working.

Disregard the last post . Used two different sata cables and plugged them into 2 onboard sata connectors. No initial errors - will let the preclear cycle complete and report the outcome.

 

Thanks

Preclear almost complete. Have noticed on of the drives in the Tools-> Preclear screen shows one of the drives cannot be precleared  (attachment Tools-Preclear.jpg), however the preclear report (attachment preclear_report_ZL2GWPN6.txt) stated the preclear operation was successful. Can I use this drive? Do I need to do another preclear?

 

Thanks for your help

preclear_report_ZL2GWPN6.txt

23 minutes ago, halfmoon said:

Preclear screen shows one of the drives cannot be precleared 

Maybe because it's spun down? If not suggest asking in the plugin support thread, though it looks like it was already successfully precleared.

Thanks for your response. You were right it was spun down - but was not able to spin-up the drive using the icon on the Main screen. As I shutdown Unraid I noticed the power light on one of the the Icy Box IB-565SSK 5-Bay storage unit was not on. I switched it on and attempted to restart Unraid. It took considerably longer to get to the 192.168.1.23 and the log in prompt on the Unraid monitor. I was unable to connect to Unraid from another port on the network using 192.168.1.23 in the browser address bar - gave the message  - cannot connect.

 

After trying to reboot several times i eventually was able to login to Unraid - did not change anything just performed several reboots. After logging in  all the drives were accessible and the preclear problem disappeared.  Looks like a hardware problem? Could one of the drives be faulty?