Can you manually enter the number ?
I recently purchased 6 300Gb disks for my FC Clariion CX300.  I have created one RAID 5 RAID group and I would like to begin carving it up for storage.  I am familiar with how to make a LUN, but I'm not sure how to make LUNs in the specific sizes that I want.  I need one LUN to be about 300Gb, one to be about 600Gb, and the remaining 700Gb to go to another server.  How would I go about doing this? 
How to Create LUNs in Specific Sizes