Hello

 

I recently decided to say goodbye to Synology and try something new with unRAID. So far everything has worked and i'm very satisfied with unRAID. However, i have the problem, that the system becomes noticeably slower when copying large amounts of data.

 

When I start the copying process, I start with about 105 MB/s, after a while the speed changes to about 50 MB/s. After a look in the forum, i changed in the Disk Settings to "reconstruct write" Mode. That only solved the problem for a short time. I found the following warnings and errors in the syslog:

 

Warnings

- Oct 1 02:19:46 myromdc01 kernel: ata21.00: failed command: READ FPDMA QUEUED
- Oct 1 02:19:46 myromdc01 kernel: ata21: hard resetting link

 

Errors

- Oct 1 02:18:55 myromdc01 kernel: ata21.00: exception Emask 0x0 SAct 0x3c00 SErr 0x0 action 0x6 frozen
- Oct 1 02:19:46 myromdc01 kernel: ata21.00: exception Emask 0x0 SAct 0x7f80000 SErr 0x0 action 0x6 frozen

 

As written in the forum i changed the SATA cables, but this had no effect.

 

Why do these error messages appear and what can i do about them? 

myromdc01-syslog-20201001-1047.zip

Please post the complete diagnostics instead: Tools -> Diagnostics

Here it is: myromdc01-diagnostics-20201001-1320.zip

Edited October 1, 20205 yr by roesti.mario

The extra controller you have is a 2 port Asmedia controller with SATA port multipliers to give the 6 or 10 total ports, these are a known problem and will cause constant timeouts, you should replace it.

Ok, thanks for your Help. Is there a general problem with SATA port multipliers or only with this Asmedia controllers? I found this alternative with a Marvell controller, would that work? Or do you have a product that you can recommend?

Any controller with SATA port multipliers is not recommended, Marvell controllers are also not recommended, even without port multipliers, if 5 ports are enough you can get a JMB585 based controller, if you need more look for an LSI HBA.