I have an Unraid system with one 6TB parity drive, two SSD cache drives and four 4TB data drives.  I believe the Unraid version is 6.3.2 or possibly 6.3.3   I cannot verify this because just recently the board has failed to POST.  Seeing this as an opportunity to upgrade, I have ordered a new system board, CPU, and RAM.

 

Searching the forums didn't turn up any thing alarming and several posts seem to indicate the system board swap should go fairly painlessly.

 

Is there anything in particular I should be aware of to replace/upgrade my system and preserve my existing drive array?

In theory it should just be a case of booting the updated system with the same drives off the existing USB stick.   If this does not work then come back and describe the symptoms so we can get you back up (and attach the diagnostics zip file).