Backup and archive processes
The backup processes and archive processes vary depending on the type of client. The following explains the various NetBackup processes involved in backups and restores including snapshot, SAN client, synthetic backup, and NetBackup catalog backup.
The job scheduler processes consist of the following:
The nbpem service (Policy Execution Manager) creates policy-client tasks and determines when jobs are due to run. It starts the job and upon job completion, determines when the next job should run for the policy-client combination.
The nbjm service (Job Manager) does the following:
Accepts requests from nbpem to run backup jobs or media jobs from commands such as bplabel and tpreq
Requests the resources for each job, such as storage units, drives, media, and client and policy resources.
Executes the job and starts the media server processes.
Fields updates from the media server bpbrm process and routes them to the jobs database and the images database.
Receives the preprocessing requests from nbpem and initiates bpmount on the client.
The nbrb service (Resource Broker) does the following:
Allocates the resources in response to requests from nbjm.
Acquires the physical resources from the Enterprise Media Manager service (nbemm).
Manages the logical resources such as multiplex groups, maximum jobs per client, and maximum jobs per policy.
Initiates the drive unloads and manages pending request queues.
Queries the media servers periodically for current drive state.
The NetBackup master server and the Enterprise media manager (EMM) server must reside on the same physical host.
The master server is responsible for running jobs as configured in NetBackup policies by using the services nbpem and nbjm.
The EMM services allocate resources for the master server. The EMM services are the repository for all device configuration information. The EMM services include nbemm and its subcomponents along with the nbrb service for device and resource allocation.