Configuring RMAN channels

Channels in RMAN perform all the tasks involving I/O, that is, backup, restore, and recover. Each channel will be responsible for the I/O stream that's going to either read from the disk while doing a backup or write to the disk while performing a restore. To make things easier, if you are taking a backup on the disk, RMAN configures a channel with the device type configured as disk by default. In addition to this, a default channel is also configured for maintenance-related commands such as CROSSCHECK, CHANGE, and so on. Let's see the nexus of the channels with RMAN via a figure:

In the previous figure, we have two channels: one for disk and another for SBT, to talk to a target database and make a connection to it. As channels are essentially sessions spawned within the target database, any task executed from the RMAN client will be executed from within the database by them.

Note

If desired, you can still allocate the maintenance channel manually using the ALLOCATE...