Parity sync is only running at 25MB/s. Brand new configuration, new cables. New power supply etc. Older drives, but pre-cleared fine at good speed (outside of case). I've got the exact same hardware config at work, it does a parity sync at 60MB/s.

 

There are some ATA errors, shown below. I did some research into it, some people say it could be faulty cable. How do I find out which cable? Is ata6 relative to anything?

 

ug  1 18:02:33 Storage kernel: ata6: limiting SATA link speed to 3.0 Gbps

Aug  1 18:02:33 Storage kernel: ata6.00: exception Emask 0x10 SAct 0x40 SErr 0x400000 action 0x6 frozen

Aug  1 18:02:33 Storage kernel: ata6.00: irq_stat 0x08000000, interface fatal error

Aug  1 18:02:33 Storage kernel: ata6: SError: { Handshk }

Aug  1 18:02:33 Storage kernel: ata6.00: failed command: WRITE FPDMA QUEUED

Aug  1 18:02:33 Storage kernel: ata6.00: cmd 61/60:30:28:3f:00/00:00:00:00:00/40 tag 6 ncq 49152 out

Aug  1 18:02:33 Storage kernel:          res 40/00:34:28:3f:00/00:00:00:00:00/40 Emask 0x10 (ATA bus error)

Aug  1 18:02:33 Storage kernel: ata6.00: status: { DRDY }

Aug  1 18:02:33 Storage kernel: ata6: hard resetting link

Aug  1 18:02:33 Storage kernel: ata6: SATA link up 3.0 Gbps (SStatus 123 SControl 320)

Aug  1 18:02:33 Storage kernel: ata6.00: configured for UDMA/133

Aug  1 18:02:33 Storage kernel: ata6: EH complete

 

Syslog attached.

syslog.txt

Hmm, found this thread: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/550559

 

Appears to be a kernel bug with the jmicron chipset? Disabling NCQ was supposed to fix the problem..

 

So, I disabled NCQ. I restarted, and *BOOM*; 90MB/s parity sync.

Where did You disable the ncq ?

 

Default disk settings ?

 

Force ncq disable ?

Yes, force NCQ disable in disk settings.

 

Intermittently still getting a link hard reset issue on random ports, but force NCQ disable seemed to make some difference.