RAID-5 performance of LSI SAS 2008m-8i in C240 M3?

[Brad_80]

Can anybody speak to the performance of the mezzanine RAID controller option in the C240, particularly in a RAID-5 configuration? I have need to configure a C240 with all 5 PCIe slots consumed with interface cards, so I will need to use the mezzanine card option. The 2008m does not support a BBU, but from what I understand, it does support write caching and does have an onboard processor for XOR offload so I would expect it has decent RAID-5/50 performance. I can't seem to find any benchmarks or documentation to confirm that.

[syedal3]

Hi Brad,

Please find the document for RAID controllers in C 240 M2 ,link mentioned below may be this can help you out.

http://www.cisco.com/en/US/docs/unified_computing/ucs/c/hw/C240/install/raid.pdf

Syed

[olexandr.valuev1]

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 other ways to write data to raid  - average speed is about 5 Mb/s.
When I use scp\cp shell or other ways to read data from raid  - average speed is about 25 Mb/s.

 

[olexandr.valuev1 · Accepted solution]

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 .