[arch-general] btrfs raid 10 fileserver with ata errors

[niya levi]

hi everyone
i have a fileserver with 6 1tb disks
i get the following errors repeated constantly

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ata17.00 exception Emask 0x0 Sact 0x0 SErr 0x0 action 0x6 frozen
failed command: READ DMA
cmd c8/00:30:       tag 14 dma 65536 in
res 40/00:ff:00       Emask 0x4 (timeout)
status {DRDY}

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after some googling it's been suggested that it's either a hard drive,
the sata controller or the sata cables.
how do i go about diagnosing and fixing the problem,
any suggestions or guidance would be appreciated.
shadrock