HBA is a PMC-Sierra PM8005 rev 5 (which I believe is a PM8001, rev 5)

 

I first noticed this issue when one of my drives, which was already in the array (precleared OUTSIDE the array, but while it was in the disk shelf) dropped during a mover task, which was executing while Plex was also updating metadata, which then required the disk shelf to be rebooted (server reboot did not resolve the issue). It actually required a disk rebuild too, as unraid somehow lost the configuration of which disk belonged in that slot, but that's another issue.

Then yesterday, I was clearing 3 8tb drives that I put in there and added to the array, and they dropped out at the same time, but interestingly, the 3TB drive in there (the one that previously dropped) was fine!

 

My first thought was that the HBA was to blame -- many people use LSI HBAs and an adapter cable, whereas I was using an HBA that worked natively with QSFP, but has significantly less community market share. Is this assessment correct? I bought a new HBA and an adapter cable, and they're on the way from ebay, but I'm wondering if this is maybe a known issue of sorts? Could it be the IOM3 controller? The fact that I only have 1 PSU plugged in on the shelf? Anyone else had this problem?

HI

 

did you found a solution for this topic ? I just got a DS4243 and same error as you .... during parity check loosing the parity drive. Before the Drives were connected directly to the HBA card with a SFF-8087 to SATA adapter, now I put the drives in the Shelf, I lost the Parity , then randomly 2 other drives.

 

As a remark, the HBA is cooled down with a fan directly blowing on itself

Previous users solved the problem by using an LSI HBA instead, you'll need a new cable though.