The following is the sequence of events for a media request for an ACS robot:

• The Media Manager device daemon (UNIX) or NetBackup Device Manager service (Windows) ltid receives the request from bptm.

• ltid sends a mount request to the NetBackup ACS process acsd.

• acsd formulates the request.

  An API then uses Internal Process Communications (IPC) to send the request on the following systems:

  • UNIX. The NetBackup ACS storage server interface acsssi. The request is then converted into RPC-based communications and sent to the ACS library software.

  • Windows. The Oracle StorageTek LibAttach service. This service sends the request to the ACS library software.

• If the Library Storage Module (LSM) in which the media resides is offline, the ACS library software reports this offline status to NetBackup. NetBackup assigns the request a pending status. NetBackup retries the request hourly until the LSM is online and the ACS library software can satisfy the media request.

• The ACS library software locates the media and sends the necessary information to the Library Management Unit (LMU).

• The LMU directs the robotics to mount the media in the drive. When the LibAttach service (Windows) or acsssi (UNIX) receives a successful response from the ACS library software, it returns the status to acsd.

• The acsd child process (that is associated with the mount request) scans the drive. When the drive is ready, acsd sends a message to ltid that completes the mount request. NetBackup then begins to send data to or read data from the drive.