Hello,

We are still fairly new to RMAN/TDPO backups, and trying to understand
behavior.

We have one 10tb database that performs RMAN backups to TSM using one
tape drive (one channel).  Oracle datafiles are interleaved (not sure of
the level).

We are now performing a full restore on this database.  The dba allocated
4 channels for the restore (4 tape drives).  We started getting session
timeouts.  It looks like Oracle was asking for aggregate files on different
channels that in TSM are on the same tape.  This caused tape contention
and session timeouts. The restore was stopped and changed to a
single channel.

I've been trying to find info on issues/limitations around  RMAN/TDPO
restores
 with multiple channels, but not finding much info.

Questions:

1)  Does the number of channels on a restore have to be the same or less
than the number used for the backup?

2)  Is it even possible to do multi channel restores?  In other words, does
RMAN have knowledge of the tape volumes so as to not cause
tape contention across channels?


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