Hello,   Just so I properly understand your question, you are referring to the EQL volume blocksize either 512 or 4K correct?   If so, then it really does not matter.  There's no performance difference at the storage level.  The drives are all 512b sectored, the 4K volume simply translates between them on the fly.   What you do want to do is set the cluster/sector size at the filesystem level to 64K.  That will match the stripe size on the RAIDsets.  This allows for more efficient reads/writes, especially writes.   \ Hopefully that answered your question?   Regards,  Don 
Hello What is the best choice for creating LUN for ReFS disks? 512 bytes or 4K bytes ? The scope is VMs hosted by Windows 2016 Hyper-V cluster. Storage are EqualLogic PS6100. Thanks
Bloc size for ReFS LUNs