Im setting up the following for a client
1 Dell R710
2 Dell 2950's
1 Dell MD3200 w/ 12 7200rpm Disks in RAID 10 and dual iSCSI Modules
1 iSCSI Dedicated Dell 5448 GB 48 Port Network Switch
I plan to cluster all 3 servers and install Hyper-V Clustered on Clustered Storage to a single LUN on the MD3200 (not including Witness LUN)
I would prefer the customer change the models to SAS but that might not be a possibility
I would like to know realistically how many VM's we can run on each server with 2 iSCSI connections to the MD3200 setup in Dynamic Least Queue Depth in MPIO (or suggest a better mode)
Each iSCSI connection will connect to a separate RAID Module on the MD3200
I know you would like to know what the virtual machines will be doing but lets just assume for now they will be a mix of standard servers, Exchange, AD, DNS, DHCP, SQL etc... just picture a nice mixture of about 30 Virtual Machines with varying disk load, nothing too heavy.
I have 4 MD3200 at my full time day job and 2 are used in 2 node SQL clusters, 1 is used for 2 Linux Nodes running Oracle and the 4th is used in a Clustered VMWare configuration. The difference is all of ours are SAS and we use all 15k drives instead of 7.2k like my current client has. Our ESXi Cluster has 3 servers and 30+ Virtual Machines and barely breaks a sweat, once I add the 4th server I plan to load anoter 20+ VM's and see no issues in the foreseeable future. It also helps that all of our SQL traffic is piped out to two SQL clusters with their own MD3200's so nothing running on our cluster has heavy disk usage.
Now my current client on the other hand will be using iSCSI and Gigabit connections which in my experience can only handle a few virtual machines per GB connection, maybe 5 depending on what they will be doing. I think 10 VM's per server running over 2 iSCSI connections will be pushing it and thats an incredible waste for the R710 which I know I can run all 30 of our virtual machines on one of our R710's with 196GB of ram and the current top of line Xeons. I dont recall what is in my clients R710 but memory can be added and as long as it has dual quads it can easily run 20 virtual machines.
Well that's all of it. Let me know what you guys think about the iSCSI connections, any real world similar setups and experiences would be very much appreciated.