Backup process
Figure: Basic backup process flow illustrates the backup procedure and the process flow during a scheduled backup.
Basic backup procedure
- The (1) NetBackup Policy Execution Manager (nbpem) initiates a backup when the job becomes due. To determine when the job is due, nbpem uses the proxy service nbproxy to get the backup policy information from the (2) NetBackup Database Manager (bpdbm).
In the case of a user-initiated backup, the backup is started when nbpem receives a request from the (3) NetBackup Request Daemon (bprd).
- When the job is due, nbpem issues a request to the (4) NetBackup Job Manager (nbjm) to submit the backup and get a jobid.
- The nbjm service communicates with (5) bpjobd, and the job is added to the job list in the jobs database. The job is now visible in the Activity Monitor, in a queued state.
- Once the job has been added to the jobs database, nbjm checks for resources through the (6) NetBackup Resource Broker (nbrb).
- The nbrb process secures the required resources from the (7) Enterprise Media Manager (nbemm) and notifies nbjm that resources have been allocated.
- After resource allocation, nbjm makes a call to the images database to create the image files in a temporary location. The required entries in the backup header tables are also created at this time. The job is now seen as "Active" in the Activity Monitor.
- Once the job is active, nbjm uses (8) bpcompatd to open a connection to the (9) client service (bpcd) on the media server. The bpcompatd service creates the connection through Private Branch Exchange (PBX) and the NetBackup Legacy Network Service (vnetd).
- The bpcd service starts the (10) NetBackup backup and restore manager (bpbrm).
- The bpbrm service communicates with (11) bpcd on the client server (through PBX and vnetd) to start the (12) backup and archive manager (bpbkar). The bpbrm service also starts the (13) tape management process (bptm).
- In the case of a tape backup, bptm reserves the drives and issues a mount request to the (14) logical tape interface daemon (ltid). The ltid service calls on the (15) robotic drive daemon (txxd, where xx varies based on the type of robot being used). The txxd daemon communicates the mount request to the (16) robotic control daemon (txxcd), which mounts the media.
In the case of a disk backup, bptm communicates directly with the disk.
- The bpbkar service sends the backup data through bptm to be written to the media storage or the disk storage.
- When the backup is completed, nbjm is notified and sends a message to bpjobd. The job now appears as "Done" in the Activity Monitor. The nbjm service also reports the job exit status to nbpem, which recalculates the next due time of the job.
Each of the processes that is involved in a backup has an accompanying log file. These logs can be consulted to diagnose any issues that you encounter with your backups.
Some additional logs that are not included in the backup process flow but that can be of use in resolving backup problems include: bpbackup, reqlib, daemon, robots, and acsssi.