B120i RAID 1 Logical drive failing

[MrLC]

I have microserver gen8 with two HGST deskstar 6TB HDD in RAID 1 for all data storage and client backup, plus Crucial 120GB SSD for WHS 2011. Also I have applied the latest SPP (P01456_001_spp-2017.10.1-SPP2017101.2017_1027.10)
 
Everything has been working just fine for past year, but recently the server just decides that logical drive for the RAID 1 with 6TB drives is failing at seemingly random times. Powering off and restarting the server fixes it, but a few days later it fails again.
 
I did move all data from the 6TB data drives to other drives I have and then proceeded to change the server to ACHI mode and run a battery of tests on each of the 6TB HDD, including full reformatting, using both Seagate's Seatools and HGST's WinDFT (windows drive fitness). No issues were found after testing them for days.
 
Since then I switched the server back to RAID mode, rebuilt the RAID 1 array, enabled Bitlocker in the entire drive. Nothing failed during that time, but later one during client back the logical drive failed again. I can't find any clue what can be the problem. I don't believe the HGST HDD are the problem since they passed the battery of tests.

Any ideas what this problem is?

 I uploaded ADU report here: https://www.dropbox.com/s/iw6wj1ai33tg4ox/ADUReport.txt?dl=0

And SSA logs here for another failure that happened last night: https://www.dropbox.com/s/4rox480caxb7owj/events.txt?dl=0

[MarcinWeg]

Hello

It is very difficult to understand hard drives errors if they are not HPE branded, no internal diagnostics and communication is not clearly understand by controller;;
Additionally please use proper SPP for Gen8 :
Service Pack for ProLiant Gen8.1:
https://support.hpe.com/hpsc/swd/public/detail?sp4ts.oid=5390291&swItemId=MTX_ff582daf008c4f529c4d6c28f6&swEnvOid=4184

Remember about fresh drivers for Dynamic Smart Array B120i :
https://support.hpe.com/hpesc/public/home/driverHome?sp4ts.oid=5390291

Regards

Marcin Weglarski

HPE employee