Problem solved.
Checked EMS Log, Shelf_ESH Log
Look for fci and esh entries:
Wed Sep 2 22:07:15 CEST [n001020: fci.link.error:error]: Could not recover link on Fibre Channel adapter 0b after 30 seconds. Offlining the adapter
<esh_word_error_1
diskID="[IN] port"
channels="PARTNER/0b"
shelfID="1"
element="ESH A "
bay=" "
reason="reports invalid word error"/>
No connections between fc adapters.
possible reasons:
failed esh modul
failed sfp transceivers
Reason: failed sfp transceiver
After replacement of sfp transceiver the resync has started. Resync completed. Everythin is fine.