On a Dell MD3860 or a NetApp E5660 you may see a message about an individual drive with a degraded path. It may also show Degraded Drive Channel.
Dell MD3860
NetApp E5660
Sometimes the storage array will self-repair this issue, but if not, generate a support log bundle using this KB article: How to generate a support bundle for Dell MD3860 or NetApp attached storage
Contact technical support for further analysis of the logs.