TSM rman备份出错

RMAN-00571: ===========================================================
RMAN-00569: =============== ERROR MESSAGE STACK FOLLOWS ===============
RMAN-00571: ===========================================================
RMAN-03009: failure of allocate command on c1 channel at 04/27/2010 15:28:32
ORA-19554: error allocating device, device type: SBT_TAPE, device name:
ORA-27000: skgfqsbi: failed to initialize storage subsystem (SBT) layer
Linux Error: 106: Transport endpoint is already connected
Additional information: 7011
ORA-19511: Error received from media manager layer, error text:
   SBT error = 7011, errno = 106, sbtopen: system error

检查logs目录下tdpoerror.log是否对oracle用户可写。