Hi to all, i'm agrre with Rodos and i add:

100Gb for 10 VM? Is a good idea to split VM in different LUN/Vmfs datastore. Leave 10% of free space in your lun and do not forgot swap file necessary at VM. You need other free space if you use VCB o generally Snapshot startegy. Keep attention also at your VM i/o type and separate VM i/o intensive in different LUN.

Bye Alberto