RMAN: Tape backups as Expired while files physically exist

Sometimes all current backups are marked as expired when performing a crosscheck backup while backupsets physically exist and these backupsets are not expired according to Media Manager like Legato or Netbackup. You should first check the Parms used in allocate channel command are correct, if they are correct you should enable the debug for RMAN for more details.
RMAN> DEBUG ON;

RMAN> ALLOCATE CHANNEL FOR MAINTENANCE DEVICE TYPE 'sbt_tape' SEND 'NB_ORA_CLIENT=OR-11, NB_ORA_SERV=mg-2' trace 1;

RMAN> crosscheck backup;
RMAN> DEBUG OFF;

Check sbtio.log in user_dump_dest location which will have the errors during the time of crosscheck.

Possible Reasons:

1- Some times errors are due to the SBT library, enabling debug can provide more insight.

2- CROSSCHECK was run with the wrong PARMS settings. RMAN will query the media manager and get response back that the backup piece cannot be found. It will then set the status of the piece to Expired.

RMAN doesn't have a concept of what media manager it is using. As long as you specify device type SBT, it's up to the user to make sure that the configuration and PARMS settings are correct. RMAN will just query the media manager generically, as it only knows that the backup was made to SBT.

12c: EM: OMS Server Fails - error nm home replaced

Environment: Oracle Enterprise Manager 12c, Windows 2008 R2
Error:Below error occured on one of the client environment
C:\Windows\system32>%OMS_HOME%/bin/emctl start oms
Oracle Enterprise Manager Cloud Control 12c Release 3
Copyright (c) 1996, 2013 Oracle Corporation. All rights reserved.
Windows service OracleManagementServer_EMGC_OMS1_1 failed to be started
Oracle Management Server is Down
Please check E://gc_inst/em/EMGC_OMS1\sysman\log\emctl.log for error details


Log file showed below

2013-12-22 10:30:54,300 [main] INFO wls.OMSController main.219 - Executing emctl command : start
2013-12-22 10:30:58,536 [main] INFO commands.BaseCommand getEnvProps.456 - nm home replaced : E:/gc_inst/NodeManager/emnodemanager
2013-12-22 10:30:58,581 [main] INFO commands.StartCommand startOMS.371 - net start return code is 2
2013-12-22 10:30:58,582 [main] ERROR commands.BaseCommand logAndPrint.620 - Windows service OracleManagementServer_EMGC_OMS1_1 failed to be started
2013-12-22 10:31:00,653 [main] INFO commands.BaseCommand printMessage.404 - statusOMS finished with result: 8

Solution:
1- Check Repository Database and Listener are up and running and Repository database is registered with the listener (lsnrctl services), start the Repository Database and its listener if required.

2- Check you can connect to Repository Database as 'SYSMAN' using SQLPLUS.

3- Shutdown the OMS

C:\Windows\system32>%OMS_HOME%/bin/emctl stop oms -force
Oracle Enterprise Manager Cloud Control 12c Release 3
Copyright (c) 1996, 2013 Oracle Corporation. All rights reserved.
Stopping WebTier...
WebTier Successfully Stopped
Stopping Oracle Management Server...
Node Manager Not Running
Oracle Management Server is Down

4- Start the OMS

C:\Windows\system32>%OMS_HOME%/bin/emctl start oms

Oracle Enterprise Manager Cloud Control 12c Release 3

Copyright (c) 1996, 2013 Oracle Corporation.  All rights reserved.

Windows service OracleManagementServer_EMGC_OMS1_1 successfully started

Oracle Management Server is Up

Exadata: Hybrid Columnar Compression & Considerations

Brief:

Exadata Hybrid Columnar Compression (EHCC) is a type of segment compression. With HCC, data is organized for storage by columns for a set of rows, this collection of groups of rows organized and compressed together is what leads to the “hybrid” tag. 

Exadata: Migration Considerations and Strategies

Once the Exadata Machine is ready, you are ready to migrate your data from your legacy hardware to Exadata. Please note that there is no difference between data segments stored in Exadata Storage Server cells and those in conventional storage unless Exadata Hybrid Columnar Compression (EHCC) is being used.  So you can use the same tools and techniques that you normally use for migration of non-Exadata systems but with some considerations. 

RMAN: Incremental Backup

Below explains a method which can be used to restore oracle incremental level backup to restore rman backups on new server to  significantly reduce restore time.
Following steps are involved.

Exadata: Storage Indexes

Brief: 
Storage Indexes are not indexes that are stored in the database like Oracle’s traditional B-Tree or bitmapped indexes. A storage index is a memory-based (heap of cellsrv) structure and its purpose is to tell Oracle with absolute certainty that a requested extent does not exist in specific locations, and Exadata uses this information to bypass I/O requests to the physical storage locations.