About the communication between NetBackup client and media server

The communication process between the NetBackup client and the media server varies depending on the following:

Whether the operation is a backup or restore
Whether the operation involves a local client or a remote client

Table: NetBackup communication during backup and restore

Type of client (local or remote)	Communication process during backup and restore
Local client	When the NetBackup media server and the NetBackup client are part of the same system, the NetBackup client is referred to as a local client. Backup of local client For a local client, the bpbkar (Linux/UNIX) or bpbkar32 (Windows) process reads data from the disk during backup and places it in shared buffers. The bptm process reads the data from the shared buffer and writes it to tape or disk. Restore of local client During a restore of a local client, the bptm process reads data from the tape or disk and places it in the shared buffers. The tar (Linux/UNIX) or tar32 (Windows) process reads the data from the shared buffers and writes it to disk. Note: Other processes may be used instead of bpbkar and bptm, depending on the data to be backed up or restored. See Processes used in NetBackup client-server communication.
Remote client	When the NetBackup media server and the NetBackup client are part of two different systems, the NetBackup client is referred to as a remote client. Backup of remote client The bpbkar (Linux/UNIX) or bpbkar32 (Windows) process on the remote client reads data from the disk and writes it to the network. Then a child bptm process on the media server receives data from the network and places it in the shared buffers. The parent bptm process on the media server reads the data from the shared buffers and writes it to tape or disk. Restore of remote client During the restore of the remote client, the parent bptm process reads data from the tape or disk and places it into the shared buffers. The child bptm process reads the data from the shared buffers and writes it to the network. The tar (Linux/UNIX) or tar32 (Windows) process on the remote client receives the data from the network and writes it to disk. Note: Other processes may be used instead of bpbkar and bptm, depending on the data to be backed up or restored. See Processes used in NetBackup client-server communication.

Type of client (local or remote)

Communication process during backup and restore

Local client

When the NetBackup media server and the NetBackup client are part of the same system, the NetBackup client is referred to as a local client.

Backup of local client
For a local client, the bpbkar (Linux/UNIX) or bpbkar32 (Windows) process reads data from the disk during backup and places it in shared buffers. The bptm process reads the data from the shared buffer and writes it to tape or disk.
Restore of local client
During a restore of a local client, the bptm process reads data from the tape or disk and places it in the shared buffers. The tar (Linux/UNIX) or tar32 (Windows) process reads the data from the shared buffers and writes it to disk.

Note:

Other processes may be used instead of bpbkar and bptm, depending on the data to be backed up or restored.

See Processes used in NetBackup client-server communication.

Remote client

When the NetBackup media server and the NetBackup client are part of two different systems, the NetBackup client is referred to as a remote client.

Backup of remote client
The bpbkar (Linux/UNIX) or bpbkar32 (Windows) process on the remote client reads data from the disk and writes it to the network. Then a child bptm process on the media server receives data from the network and places it in the shared buffers. The parent bptm process on the media server reads the data from the shared buffers and writes it to tape or disk.
Restore of remote client
During the restore of the remote client, the parent bptm process reads data from the tape or disk and places it into the shared buffers. The child bptm process reads the data from the shared buffers and writes it to the network. The tar (Linux/UNIX) or tar32 (Windows) process on the remote client receives the data from the network and writes it to disk.