Loads of our configurations are A port to A port for 10 stack, B port to B port for 20 stack, etc (where one is SAS and the other SATA). I see no reason right off why you couldnt have them on the same adapter. As I understand it, the ports are capable of either 3 or 6gb so really it shouldnt matter.
As for the advantages, density, power, and cooling are the big ones that come to mind. Yeah the shelves aren't cheap, but they're capex and cant be depreciated whereas power and cooling are ongoing. What you may pay for upfront could end up being beneficial in the longer term for dollars and cents saved. As for the mixing disks statement, go with that and dont do it..
Just my $0.02..
Feb 27, 2013 07:46:33 PM, jeff.cleverley@avagotech.com wrote: Greetings,
We will be upgrading an existing 6080 cluster to a 6280 cluster. We also have a 6080 cluster we'll be adding disks to also. Both clusters are 7-mode. We'll probably end up at 8.1 on both clusters. My 2 questions stem from the disks and shelves being proposed for the upgrades (ds2246 with 450g SAS).
- We currently have DS4243 shelves with 600gig SAS. I know I can't
mix these in the same stack because of the 3/6gb connection differences. I have a free port on each SAS adapter in our 6080s. Can I put the 6gb shelves on the same adapter as long as they are on their own stack? I'm guessing it may not be a best practice, but we don't have any slots free in the 6080 for more cards.
- I found a white paper that states the 10K drive performance can be
up to 20% slower than the 15K SAS drives for random reads. That seems like a pretty big performance it. It also says mixing the disks in aggregates is not recommended. Other than the smaller footprint and better density, I'm not seeing an advantage over using 600g SAS in the DS4243 shelves. Are there any advantages other than the faster SAS backend to warrant going to these shelves in our environment?
Thanks,
Jeff