The following diagram is listed the commmon possible SAN connectivity issues, it is very useful for troubleshooting.
- Switch firmware or hardware issues that cause a path to become unavailable.
- Cables that have been mistakenly unplugged, and dirty or poorly seated (or broken) connectors.
- SAN zoning issues, where host and storage devices are not zoned to communicate with one another, or devices that were zoned become un-zoned for one reason or another; or after some zoning changes, the previous Zoneset was set active again (usually operator error).
- Fabric rebuild issues, where a bad link between two switches keeps bouncing between online and offline states, causing a constant stream of fabric reconfigurations so that data traffic is severely limited.