If your ESX servers are not connected to network storage or if you do not have enough available space on your SAN to dedicate a sub folder of a VMFS volume for ISO files, then you can use a NFS network share to centrally store these images. Creating the NFS share can be done with many server operating systems, but did you know that Windows Server 2003 R2 has native NFS?

VMware-land.com has many “how to” VMware Tips for ESX, and the following is the instructions found there for creating a Windows 2003 R2 NFS share:

1. On the Windows 2003 Server make sure “Microsoft Services for NFS” in installed. If not you need to add it under Add/Remove Programs, Windows
   Components, Other Network File and Print Services
2. Next go to folder you want to share and right-click on it and select Properties
3. Click on the NFS Sharing tab and select “Share this Folder”
4. Enter a Share Name, check “Anonymous Access” and make sure the UID and GID are both -2
5. In VirtualCenter, select your ESX server and click the “Configuration” tab and then select “Storage”
6. Click on “Add Storage” and select “Network File System” as the storage type
7. Enter the Windows Server name, the folder (share) name and a descriptive Datastore Name
8. Once it finishes the configuration you can now map your VM’s CD-ROM devices to this new VMFS volume

Repeat steps 5 through 8 for each of your ESX servers to make the same ISO files available to all ESX hosts.

These instructions assume that you have already configured the VMkernel port group on a vSwitch for each ESX host. For instructions and information about configuring the VMKernel for NAS/NFS storage check the Storage Chapter of the ESX Server 3 Configuration Guide.

Of course, you can use the NFS share for more than just ISO file storage too. This is a good repository for patches and scripts that need to be used on all hosts. NFS also makes a good target for VM image backups too. Use some imagination and install the free VMware server on your 2003 R2 box and you have a low budget DR platform. Oh yeah, I shouldn’t forget to mention you can even run ESX VMs from NFS!