Today I logged in to the dashboard and was greeted with a red x beside one of my drives, clicking on it shows "Unavailable - disk must be spun up" and clicking spin-up does nothing.

 

I've attached the diagnostics package, I would appreciate if someone could explain what is actually happening.

 

Thanks,

unraid-diagnostics-20170124-1457.zip

Your disks' SMART reports look good but the 6 TB ones are showing evidence of SATA cabling problems. Shut down and check your cables.

 

See this recent post.

Your disks' SMART reports look good but the 6 TB ones are showing evidence of SATA cabling problems. Shut down and check your cables.

 

could I ask what you see in the smart report that would lead you to that? I'm genuinely curious.

SMART attribute 199 UDMA CRC Error Count shows SATA data errors. They could be due to a dying SATA port or failing drive electronics but much, much more likely a bad or poorly seated SATA cable, or even crosstalk from another SATA cable.

 

199 UDMA_CRC_Error_Count    0x0032  200  200  000    Old_age  Always      -      2789

 

EDIT: What you want is for that figure not to keep increasing. If it does you still have a problem. Cable OCD is not good in this case - long parallel runs are not a good idea. Flexible cables with locking tabs laid out slightly messily are best!