WriteBack was default false so that is off, can I enable that without recreating the LUN?
CPU i7-4790, cache is an old WD green 2TB, parity is an WD red 10TB and the array is a mix where the newest ones are WD Red 10TB
Edit: Tried with an new LUN with writeback enabled, now it goes over 100MB/Sec for some time, then drops to 3-4MB/sec, then back to over 100MB and so on. Looks to me a cache is filling up, then waiting for the drive, then filling the cache and so on. This was tested on a FileIO on the cache drive.
Same happens with the LUN on the array.
Going to try on a BlockLUN when I can, but I only have old WD green 2TB drives laying around.
Read speeds was way better, 95% over 150MB/sec (from both WriteBack on and off LUNs), and read is more important for me than write so at least that is good