Since starting at VMware I've spoken to a lot of people who've told me they have problems finding good VMware best practice documentation for HDS Storage. I was fortunate enough to attend the HDS Bloggers Day back in April, at which I met some great people and made some good contacts. I've been in touch with them and spoken to them about my colleagues views on the lack of good HDS documentation relating to vSphere and they pointed me to the following website:

http://www.hds.com/go/oneforall/thankyou.html
http://www.hds.com/solutions/applications/application-vmware.html

The site contains many PDF's and video's including:

• Advantages of Hitachi AMS2000 family in vSphere 4 Environments
  
• Implementation Guide: Deploying Hitachi NAS with vSphere
• Using vSphere with Dynamic Provisioning Software for AMS2000

So if you're using HDS Storage, it might be worth giving it a look.  

If you can't find something you need on there, contact me via the Contact page and I'll get in touch with Hitachi for you.

Update: I've managed to get another couple of links for you:

• AMS – http://www.hds.com/assets/pdf/optimizing-the-hitachi-ams-2000-family-in-vsphere-4-environments.pdf
• USPv – http://www.hds.com/assets/pdf/optimizing-the-hitachi-universal-storage-platform-family-in-vmware-environments.pdf