Your ESXi boot configuration must meet specific requirements.

Table 1. Boot from SAN Requirements
Requirement Description
ESXi system requirements Follow vendor recommendations for the server booting from a SAN.
Adapter requirements Configure the adapter, so it can access the boot LUN. See your vendor documentation.
Access control
  • Each host must have access to its own boot LUN only, not the boot LUNs of other hosts. Use storage system software to make sure that the host accesses only the designated LUNs.
  • Multiple servers can share a diagnostic partition. You can use array-specific LUN masking to achieve this configuration.
Multipathing support Multipathing to a boot LUN on active-passive arrays is not supported because the BIOS does not support multipathing and is unable to activate a standby path.
SAN considerations If the array is not certified for a direct connect topology, the SAN connections must be through a switched topology. If the array is certified for the direct connect topology, the SAN connections can be made directly to the array. Boot from SAN is supported for both switched topology and direct connect topology.
Hardware- specific considerations If you are running an IBM eServer BladeCenter and use boot from SAN, you must disable IDE drives on the blades.