A server administrator notices when a specific server is re-booted its SAN storage is sometimes visible and sometimes it is not. After examining the SAN switch logs, no FLOGI message has been…

If the HBA's Port Link/Speed is set to 'Autonegotiate' and there is an incompatibility or fault in the autonegotiation process with the connected SAN switch port, the physical link may fail to establish reliably. A failed link prevents the HBA from sending the crucial FLOGI (Fabric Login) message to the switch, leading to the SAN storage not being detected intermittently.

WWPN reset timeout relates to the HBA's behavior after a link reset, not the initial or intermittent failure of the FLOGI message due to link establishment issues.

R_A_TOV (Resource Allocation Timeout Value) is a Fibre Channel parameter for error recovery and resource allocation, not directly for initial physical link establishment or FLOGI.

An HBA Port Type set to 'E-Port' is for inter-switch links (ISLs) and would cause a consistent rather than intermittent failure for a host HBA, which typically operates as an N-Port.