Steve,

Rman will hold all channels until it finishes it processesing on the
entire backup job. Rman usually does a good job making sure that the
channels get equal amount of work but you can imagine that in some
instances the majority of the work load goes to one channel. For instance:
channel t1 backs up the control file and several small datafiles that
equal 100mb while channel t2 gets a datafile (maybe the remaining backup
piece) that is 700mb. In this case channel t1 will have finished long
before channel t2 and then Rman holds the resources of t1 until t2
completes.


Date:    Mon, 22 Oct 2001 15:50:23 +0800
From:    Steve de Souza <DeSouzaS AT BUNNINGS.COM DOT AU>
Subject: rman question

Hi there

        I use tdp for oracle 2.2 on a tsm4.2 server
        I allocate 2 channels for the rman backup, t1 and t2
        when the backup starts, it initially starts to write to 2 tapes.
        After a short while, one drive goes idle and the other tape
        continually gets written to, till completion of the backup.

        Anyone have any idea as to what is causing one the tapes to go
        idle?

        The backup files aren't very big.
        channels t1 and t2 continue to get 'allocated' to completion if
the
job.
        The mountretention on the devc is big.
        what else could I check?

        cheers

        steve


Regards,

Neil Rasmussen
Software Development
TDP for Oracle
rasmussn AT us.ibm DOT com