Event ID Excluded condition Extent External storage Failback Failover Feature activation code Fibre Channel port logins Field-replaceable unit FlashCopy FlashCopy mapping FlashCopy relationship See FlashCopy mapping. A FlashCopy mapping is a continuous space on a direct-access storage volume that is  occupied by or reserved for a particular data set, data space, or file. FlashCopy refers to a point-in-time copy where a virtual copy of a volume is created. The  target volume maintains the contents of the volume at the point in time when the copy was  established. Any subsequent write operations to the source volume are not reflected on the  target volume. Field-replaceable units (FRUs) are individual parts that are replaced entirely when any one of  the unit’s components fails. They are held as spares by the IBM service organization.  FC port logins refer to the number of hosts that can see any one V7000 port. The IBM  Storwize V7000 has a maximum limit per node port of FC logins that are allowed.  An alphanumeric code that activates a licensed function on a product. Failover is an automatic operation that switches to a redundant or standby system or node in  a software, hardware, or network interruption. See also Failback. Failback is the restoration of an appliance to its initial configuration after the detection and  repair of a failed network or component. External storage refers to MDisks that are SCSI logical units that are presented by storage  systems that are attached to and managed by the clustered system. An extent is a fixed-size unit of data that is used to manage the mapping of data between  MDisks and volumes. The size of the extent can range 16 MB - 8 GB. The excluded condition is a status condition. It describes an MDisk that the IBM Storwize  V7000 decided is no longer sufficiently reliable to be managed by the cluster. The user must  issue a command to include the MDisk in the cluster-managed storage.  An event ID is a value that is used to identify a unique error condition that was detected by the  Storwize V7000. An event ID is used internally in the cluster to identify the error. 776  Implementing the IBM Storwize V7000 with IBM Spectrum Virtualize V8.2.1