Category: "Old stuff"
This is post copied from the old blog that seems to be relevant even now. Basically, those using P400/P400i on ESXi usually hit the major issue: cciss driver provided by ESXi does not support LUNs >2Tb in size while controller itself (with newer firmwares) does. Alas, it's not only driver problem but essentially the ESXi SCSI emulation layer issue is involved and so directly patching cciss driver was impossible.
What's provided there is pair of drivers for ESXi 5.1 (both VIBs must be installed for support to work) that make hpsa driver claim the P400(i) controller and cciss driver to ignore it. Of course, you should have driver support level set to 'third-party' for this to work, effectively making your ESXi system unsupported.
These VIBs were tested for years by multiple people with ESXi 5.5 and even 6.0, and found working. Nevertheless, they are obsolete AF now and always should be used at your own risk only. I hereby propose they come without any warranties and I cannot be made liable for any data loss, broken extremities, major traffic accidents or whatever resulting from your use of this driver set. It is provided only because people still search for it and find it useful.