Hello Everyone

My system is flooded with following error messages. Can any one explain what these error messages are?

alert_T001.log.104:ORA-19624: operation failed, retry possible
alert_T001.log.104:ORA-19506: failed to create sequential file, name="c-2741018382-20060822-0f:1", parms=""
alert_T001.log.104:ORA-27028: skgfqcre: sbtbackup returned error
alert_T001.log.104:ORA-19511: Error received from media manager layer, error text:
alert_T001.log.104:ORA-19583: conversation terminated due to error
alert_T001.log.104:ORA-27191: sbtinfo2 returned error
alert_T001.log.104:ORA-19511: Error received from media manager layer, error text:
alert_T001.log.104:ORA-19624: operation failed, retry possible
alert_T001.log.104:ORA-19506: failed to create sequential file, name="c-2741018382-20060822-69:1", parms=""
alert_T001.log.104:ORA-27028: skgfqcre: sbtbackup returned error
alert_T001.log.104:ORA-19511: Error received from media manager layer, error text:
alert_T001.log:ORA-00230: operation disallowed: snapshot controlfile enqueue unavailable
alert_T001.log.104:ORA-19624: operation failed, retry possible
alert_T001.log.104:ORA-19506: failed to create sequential file, name="c-2741018382-20060822-0f:1", parms=""
alert_T001.log.104:ORA-27028: skgfqcre: sbtbackup returned error
alert_T001.log.104:ORA-19511: Error received from media manager layer, error text:
alert_T001.log.104:ORA-19583: conversation terminated due to error
alert_T001.log.104:ORA-27191: sbtinfo2 returned error
alert_T001.log.104:ORA-19511: Error received from media manager layer, error text:
alert_T001.log.104:ORA-19624: operation failed, retry possible
alert_T001.log.104:ORA-19506: failed to create sequential file, name="c-2741018382-20060822-69:1", parms=""
alert_T001.log.104:ORA-27028: skgfqcre: sbtbackup returned error
alert_T001.log.104:ORA-19511: Error received from media manager layer, error text:
alert_T001.log:ORA-00230: operation disallowed: snapshot controlfile enqueue unavailable
alert_ADVFRW1.log.59:ORA-19624: operation failed, retry possible
alert_ADVFRW1.log.59:ORA-19506: failed to create sequential file, name="c-3450028546-20060823-05:1", parms=""
alert_ADVFRW1.log.59:ORA-27028: skgfqcre: sbtbackup returned error
alert_ADVFRW1.log.59:ORA-19511: Error received from media manager layer, error text: