Red Hat Knowledgebase

As a rule of thumb, the root filesystem (/), the boot filesystem (/boot), and the primary swap space should all be on local storage.

Booting from Storage Area Network(SAN) volumes complicates the boot process by introducing the non-determinism of a shared storage array and a Fibre Channel or iSCSI network into a boot sequence that is designed to be deterministic. Red Hat Enterprise Linux 5 is designed to tolerate typical SAN behavior and boot reliably with little custom configuration, provided the host bus adapter is capable of functioning as a boot device, and is configured to do so. Booting from local storage is still recommended.

Previous releases are more sensitive to the variations in SAN behavior, and may require more extensive tuning to reliably boot from SAN volumes. Some SAN vendors support booting Red Hat Enterprise Linux releases 3 and 4 in certain configurations. Users wishing to boot these releases from SAN volumes are advised to contact their SAN vendors for assistance.