I randomly see this error in the logs "Tower1 kernel: ata1.00: exception Emask 0x10 SAct 0x0 SErr 0x90202 action 0xe frozen" and when I tried running the parity check earlier, it was crawling. I've read in past threads that this is usually due to a bad sata cable but need a little help figuring out which one to replace. I've attached the full diagnostics. Is it disk1 and disk6 or do I need to count the parity drives too? 

 

tower1-diagnostics-20191008-0422.zip

If I have read the diagnostics correctly the the ata1 and ata6 devices correspond to the parity1 and parity2 drives - not disks 1 and 6.    you are correct to say that this type of error is a connection issue typically relating to the SATA connection to the drive in question.   Resets of this type have the symptom of slowing down disk I/O due to the delays introduced as the drive(s) continually reset.
 

To identify the drives you need to start by searching the syslog for the ataX type strings until you find the entries where they are associated with a particular disks serial number to identify the correct drive(s).

Thanks for the feedback and tips @itimpi. Looks like you are correct, searching for "ata1" and "ata6" in the logs did point me to the parity drives. I'll swap out those cables and keep an eye on the syslog. Thanks again!

Edited October 8, 20196 yr by Rock G

On the Main page click on the disk icon of a device and it shows the associated log with the disk.

Super useful this!

Helped me pick up the issue why my one desk kept giving issues, seems the sata power connector to it was faulty, swopped it and all working!