EMC Clariion LUN size - best practice

FC disks are usually used for high performance application need while SATA is for lower performance with high storage capacity needs. The LUN size totally depends on your application capacity needs. There is no best practice for a LUN size.  But We do have best practice for RAID Group configuration, like 4+1 or 8+4 for RAID 5, 4+4, 8+8 for RAID10. 6+2, 8+2 for RAID 6.

The general direction for VMware is to go with larger and larger pools of compute, network, and storage.  Makes the whole cloud thing simpler.  Thus the increase of support from 2TB to 64TB LUN’s.  I wouldn’t recommend going out and creating 64TB LUN’s all the time.  Because of VAAI the locking issue goes away.  The pathing issue is still there with native multipathing but if you go with EMC’s PowerPath/VE then that goes away.  So then it comes down to how big the customer wants to make their failure domains.  The thinking is that the smaller the LUN the less VM’s placed on it thus the less impact if a datastore/LUN were to go away.  Of course we go through great lengths to prevent that with five 9’s arrays and redundant storage networks, etc.  So, the guidance I’ve been seeing lately is 2TB datastores/LUNs is a good happy medium of not too big and not too small for general purpose VM’s.  If the customer has specific requirements to go bigger then that’s fine, it’s supported.

For more information, I strongly recommend you read the thread of Best practice for VMware LUN size

and the document of planning the number and size of LUNs and volumes for CSV.

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glen