UNIX client restore
Before you start a restore, use the bplist program on the client to do the following: browse the file catalog to list the files available in the backup images, and select the desired files. You can start bplist directly from the command line, and the NetBackup user interface programs can use it.
To retrieve the file list, bplist sends a query to the request daemon (bprd) on the master server (see Figure: List operation - UNIX client). The request daemon then queries bpdbm for the information and transmits it to bplist on the client.
The following are the processing steps in a restore (in the order presented):
When the user starts a restore, NetBackup invokes the client's bprestore program which sends a request to the request daemon, bprd. This request identifies the files and client. The request daemon then uses bpcd (client daemon) to start the backup and restore manager (bpbrm).
Note:
To restore Backup Exec images, bpbrm initiates mtfrd instead of nbtar on the clients. The server processes are the same as those used for NetBackup restores.
If the disk device or tape device on which the data resides attaches to the master server, the following occurs: bprd starts the backup and restore manager on the master server. If the disk unit or tape unit connects to a media server, bprd starts the backup and restore manager on the media server.
The backup and restore manager starts bptm and uses the client daemon (bpcd) to establish a connection between NetBackup nbtar on the client and bptm on the server.
For tape: The bptm process identifies which media is needed for the restore, based on the image catalog. bptm then requests the allocation of the required media from nbrb through nbjm. nbjm then asks mds (part of nbemm)for the resources. nbemm allocates the media and selects and allocates an appropriate drive (for tape media).
bptm asks ltid to mount the tape in the drive.
For disk: bptm does not need to ask nbrb for an allocation, because disk inherently supports concurrent access. bptm uses the file path in a read request to the system disk manager.
bptm directs the image to the client in one of two ways. If the server restores itself (server and client are on the same host), nbtar reads the data directly from shared memory. If the server restores a client that resides on a different host, it creates a child bptm process which transmits the data to nbtar on the client.
Note:
Only the part of the image that is required to satisfy the restore request is sent to the client, not necessarily the entire backup image.
The NetBackup nbtar program writes the data on the client disk.
Note:
PBX must be running for NetBackup to operate (PBX is not shown in the next diagram). See the NetBackup Troubleshooting Guide for more information on how to resolve PBX problems.