Is is possible to set up ESXi or more expensive ESX server as a storage target (FCoE, ISCSI or NFS, in that order) for other ESX servers? If so, how?
One solution would be to set up a VM guest on the ESX / ESXi server running something like openfiler which is a linux based open source storage server
It can be downloaded from http://www.openfiler.com/ and supports iSCSI and NFS - not sure about FCoE
You can install Openfiler or FreeNAS or similar project and pass whole physical hard drive(s) to this virtual machine (VMWare Raw Disk Mapping - RDM). Then you can easily configure Openfiler as FCoE Target or iSCSI target or NFS Server.
You can configure your ESXi manually.
vmkfstools -r /vmfs/devices/disks/vml.01000000002020202020205354463630374d473356304a554b486974616368 testdisk_1.vmdk
and then edited the servername.vmx to include the following lines:
scsi0:1.present = TRUE scsi0:1.fileName = /vmfs/volumes/datastore2/DC1/testdisk_1.vmdk
Here is complete HOWTO configuration Openfiler as iSCSI target for ESX/ESXi.