We're adding some more storage to our Clariion array, another tray of 450GB disks. Some of this storage we'll use for our ESXi servers, either adding to our existing datastores or creating new datastores. Our current design is four RAID5 arrays with 5 disks each, two of the arrays are with 300GB disks, two with 450GB disks. Each array is carved into 200GB LUNs and two 800GB metaLUNs are formed with these, each one getting one LUN from each array. These metaLUNs are the basis for our two VMFS datastores.
With this in mind, what's the best method to add more storage? We could create two more RAID5 arrays with the 10 new disks and make four more 200GB LUNs, adding two (one from each array) to each metaLUN to make two 1.2TB metaLUNs. This would be the easy way but are we going to start having SCSI contention issues? There are currently around 20 VMs on each VMFS with a variety of load types.
All the articles I'm finding don't mention metaLUNs and so I don't know what effect that would have. After we are done with the VMFS setup we will be moving Exchange and the file server to this storage, both are currently using iSCSI off a different array right now.
The advantage I see to adding more LUNs and making bigger VMFSs is that the load will be spread across another 10 disks.
Any storage experts care to chime in?
Thanks,
Mitch
