Networker stopped backing up to one of the pools

Networker (on DataDomain) has several pools:
# nsrmm -C
Data Domain disk Dataeth. 001 mounted on dd6800-vc1.vaz.ru_Data-eth, write enabled
Data Domain disk FA.002 mounted on dd6800-vc1.vaz.ru_FA, write enabled
Data Domain disk Oraclefc.001 mounted on dd6800-vc1.vaz.ru_Oracle-fc, write enabled
Data Domain disk Oracleeth. 001 mounted on dd6800-vc1.vaz.ru_Oracle-eth, write enabled
Data Domain disk Index. 001 mounted on dd6800-vc1.vaz.ru_Index, write enabled
Data Domain disk Datafc.001 mounted on dd6800-vc1.vaz.ru_Data-fc, write enabled

Backups stopped going to the Dataeth.001 pool. There are several politicians and clients. Not a single backup is completed.
On other pools backups pass.
What should i do?