Any Seagates in there?
Also, what does the S.M.A.R.T. values tell you?
A few days ago, I noticed the the power LED on the computer case started to flicker. It looked almost like it was a HDD indicator and would sometimes be 100% bright and other times only a fraction of normal brightness. At the same time this started occurring, I started getting random error emails that a ZFS RAID array could not be found. This is an Ubuntu 16.04 file server.
The two culprits that come to mind first are the motherboard or the PSU. The motherboard is ~1 year old Asus M5A78L-USB3/Plus and the PSU is a brand new Seasonic 550W G series. I also recently upgrade the CPU to an new AMD FX 8350 I picked up for cheap. Can anyone recommend either good articles, or procedures to do some troubleshooting to see if I can determine the cause?