Hi,
the ML310e Gen8 has a Dynamic Smart Array B120i RAID controller onboard. To make this available to VMWare you need to use the HP customized VMWare installation image (no matter if you install VMWare 5.5 or 6).
The B120i together with the B320i is not on VMWare's HCL and the driver is a partner (HP) supported one, that's why you need to use the customized images.
Prior to any VMWare installation I would run the latest HP SPP (Service Pack for Proliant) and update the server's BIOS and all firmware (iLo, Smart Array, NICs etc.) to the latest.
As for VMWare 6 there are several discussions in VMWare community claiming that the Smart Array B120i/B320i VMWare driver (hpvsa) version 9x is not working correctly and causing either performance issues or host crashes.
If you do not need to intall/use the latest VMWare version 6 you may try to install 5.5 Update 1 HP customized first, this includes verion 88 of hpvsa which is known to be working.
Otherwise you may need to downgrade to an 8x version of the driver after installation.
cykVM