LUN Expansion is the process of creating a metaLUN Stroage object. An expansion is similar to a FLARE LUN bind. The component LUNs are joined to the base LUN to create a larger logical storage object. LUN Expansion does not create a new physical storage object. To a host, this new logical stroage object (the metaLUN) appears as the original base LUN (you will see unallocated space one you expand a LUN), except with additional storage capacity.  FYI: The number of metaLUNs that may be created on a CLARiiON is dependent on the CLARiiON model, and secondarily on the storage system's FLARE OS revision.  There are 2 methodes of LUN expansion : - Concatenation - Striping  If you are expanding the LUN with Concatenation method the componenet LUN will be available immediately with out any performance impact. However, if you use Striping it will ethe data across and it does have some sort of performance until the data is restriped and then it will take it as 1 single lun.  1. If you are going to use concatination I would go with 1TB as it will add 1 single component LUN.  2. huh?! Please, elaborate? If I understood correctly, you will expand a LUN with Striping method on storage system and your host team will concat that LUN from the Host? Are we talking VMWare here? RDM etc..?  If not, please elaborate the second query, if needed.  You can find detailed information about metaLUN concepts in: Whitepaper: MetaLUN Concepts.
1) I need to provide a  capacity of 1tb  of Raid 5.So which will be the best way creating metas of 500+500  or creating 250+250+250+250  or the last option 1TB single lun.Which will give me best perfromance   2) Suppose i give a meta lun which will be striped ...and our host team concats that lun so stripe from storage and concat from host will cause a performance or not ????
Meta luns