Finally, we replaced Cisco UCSC RAID SAS 2008M-8i (SLOT-MEZZ) with LSI MegaRAID SAS 9271-8i with cahce memory and BBU (with TMM-C SuperCap) and enabled Write Back cache policy - disk performance fantastically improved .

You are absolutely right - performance of this raid controller is awful.We using UCS C220 M3S server with Cisco UCSC RAID SAS 2008M-8i (SLOT-MEZZ), 8 Toshiba MK3001GRRB drives in RAID-5 , and ESXi 6.0.0 as operation system.When I use scp\cp shell or ...