I am in the final stages of purchasing a 2240 and wondered if someone could spare some time to answer a few questions.
First of all the usage case is as follows: -
1. Fully VMWare virtualised environment containing SAP ECC 6, Exchange and a few other SQL Databases.
2. About 50 virtualised servers of which 10 would be classed as high load.
3. Currently running on a EMC CX4 - 120 due for replacement with a mixture of 300GB 10K Fibre, 146GB 15K Fibre drives for high load systems (about 30 fibre disks in the system), and 9 SATA 1TB in RAID 5. Mostly RAID 5 and 1 however SAP DB on 8 146GB disk RAID 10.
4. IOPS are currently around 6000 with latency times below 14ms across all Fibre and 40ms across SATA.
5. Current SAN is 3.3 TB useable Fibre of which 2.5TB is used and 8TB SATA of which 5TB is used
6. Load for SATA is mostly Read, Exchange about 90% read (300GB db) , and SAP about 90% read (400GB db), VMware LUNS equal read/write balance.
We are looking to buy.
1. 2240-2 with 24 x 10k 600GB SAS
2. A shelf of disk 2246 or 4243 with 24 x 600GB SAS
3. All the Snap products to allow us to snap Exchange, SAP, VM's
Questions are: -
1. What shelf should we go for and why? I know that 10k SAS only in 2246 for instance and would this be an issue?
2. Is the 2240-2 with this drive setup in your opinion the right choice?
3. How would you calve up this configuration (Aggregates / Lun sizing for VMware Luns)
Feel free to let me know if there isn't enough detail
I would have your SE work with you on a sizer exercise. It won't take too much time if the inputs or assumptions are known. That will help decide the right controller and number of spindles and type of spindles. Since the 10k drives in ds2246 are 2.5" they do have good IOPs with a smaller form factor... in my sizing exercises we find that sizing equivalents for ds2246 10k drives and ds4243 15k drives are about a 20% delta... so if we need 7 shelves of ds4243, we need about 9 shelves of ds2246 for the same performance when running the application sizers... but every sizing is unique, so best to run through the sizing exercise and the output will tell you how many types of each disk and shelf are equivalent for your requirement.
It will take a deeper dive, but you probably will go with 1 or 2 aggregates to get the most I/O out of each aggregate.
The sizers are very, very good... but garbage in, garbage out So if they are recommending something wrong they may also be putting incorrect inputs. 2240 is a really nice platform...be prepared to upgrade Data ONTAP to GA and patch releases as needed since 8.1 is very new (and very cool, but still RC code). Once GA you will be able to set on a release you can stay on for longer than the rc code that ships.