Oracle Restore Using Only a Single Tape Drive

[GregE]

I know this has been discussed, but I see nothing that pertains to my issue. I have an Oracle node allowed 6 mountpoints. It backs up LANFree using 5 RMAN channels, i.e. 5 tape drives.

Now we are restoring, allocating 4 RMAN channels. It is only using one. It is a 5TB DB and has been running the restore for 18+ hours, never using more than one drive (channel "t1" in RMAN). I see many tapes mounting/dismounting/remounting, etc., using different tape drives, so the data is definitely spread out over many tapes, but it will NOT use more than any one tape at any one time. I see 4 drives with tapes in them, but Q MOUNT always shows only one of them "IN USE" while 3 are always "IDLE" because RMAN is not using multiple channels even though the RMAN script has 4 allocated.

Based on all of this, is there anything else that needs to be checked? Is this all on the Oracle RMAN side? Anything that you know of that the DBA could do there? (either now during the restore, or for future restores?)

 

[moon-buddy]

This behavior is expected since the database has to be reconstructed.

For this reason, I don't use LAN Free direct to tape for Oracle DB backup but rather dump everything to disk and do tape collocation by node for Oracle DB backup. I get faster restores by not mounting so many tapes.

Least to say - been there, done that.

 

[GregE]

Thank you.

IBM pointed to a RMAN setting that we'll be testing next week as well...

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Oracle 10G RMAN Restore Unable To Open Multiple Channels

Problem(Abstract)
TDP for Oracle may not be able to open multiple channels for an RMAN restore after Oracle upgrade to 10G.
.
Resolving the problem
In the RMAN script for restore, add the following line to disable the Oracle 10G change and re-enable the ability to process the RMAN restore through multiple channels:
set parallelmediarestore off;

An article pertaining to this RMAN flag has been reported as available in Oracle's Metalink support site as document 358171.1

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[GregE]

This RMAN option worked.