You are most welcome Vic. So let us talk first  about SYMM MAXIMUMs here, So for SYMM VMAX series the max standalone device is 240 GB and if you want to create METAs you have  a limit of 255 members so the max size you can create out of  a SYMM device is almost 60 TB. This has been tested and approved by EMC labs. However, I will not create a single datstore of this size for many reasons, If i want to replicate using SRM/SRA, The remote array may not have enough disk space to create 255 dev of size 240 GB to create the RDF pair, Another thing, comes when you have IO intensive machine, This MAY dramatically affect the performance of other VMs, Add to this the LUN queuing at VMKERNEL level etc...(This can be changed if recommended by vmware though!).  So my advice is to use, 2 or 4TB datastores and do not concatenate on the ESX level, Just create 8-way META with member size of 240 GBs (approx. 1.88 TB) or 16-way META for size of 240 GBs each member (almost 4 TB)  2 or 4 TB should work with almost 95-99 % of your workload, If you have  a machine that needs more than that, Then use the new storage enhancements like jumbo vmdk (with vmware esxi 5.5) on a new sperate datastore or so,  When you want to expand in the future, For Concatentaed METAs just add a new device of same configuration to the META head and expand from ESXi host. For Striped META, using protect_data option you can expand but you will need to create a BCV device to with the same configuration as the current Striped META.  I will not recommend using extents/chunks of datastores from ESXi level. Losing one of these may corrupt the whole infrastructire due to the fact that vmkernel stripes the writes across all extents so loss of one is like loss of all. VMware support have very limited options to recover the datastore.  You can leverge Datastores clusters. It is  areally nice feature but make sure you combine datastores of same technology to have a reasonable recommendations by SDRS.  So combine 2x4 TBs datstores into one Cluster and let SDRS make decisions.  A really good & recommended techbook document was written by Drew and Cody, You can find it in the below link:  [URL]  Hope this helps Mohammed Salem
Hello to the group,  We currently use NFS for ESX datastores but will be moving to VMAX block storage. I'm sure many of you have experience in this environment so I wondered if anyone would mind sharing how you manage provisioning to ESX in terms of a standard lun size.  I've been considering the idea of a 4TB standard lun created as a striped meta and for ESX I'd prefer to provision them in batches so that it only needs to occur infrequently. Idealy these would be used for individual datastores and never expanded.  What works best in your environment? Do you concatenated standard sized luns or use them as one lun per datastore? Do you allow expansion?  I've read the best practices doc and don't believe these questions are fully covered. Probably because there's more than one correct answer and it depends on the environment. I'm just looking for a starting point and examples of things that have been shown to work.  Thanks, Vic
LUN standard for ESX clusters.