On the host where Oracle runs, I do RMAN backup to its +FRA diskgroup. Now I want to duplicate part of it (one tablespace I need plus system, undo, sysaux) to the file system /u01/temp/davidh, creating a new instance called davidh. I've done exactly the same before except for another DB on another host so I'm following my note. But this time duplicate can't find the backup piece. The command below is run when davidh is up in nomount state and accessible as sys, and current oraenv is set to the target instance. $ rman target / catalog rman@oirp auxiliary sys/davidhpwd@davidh ... RMAN> duplicate target database to davidh 2> pfile=/u01/temp/davidh/initdavidh.ora 3> skip tablespace ...[a long list of tablespaces]... 9> until time "to_date('20101209 10:00','yyyymmdd hh24:mi')" 10> logfile '/u01/temp/davidh/redo01.log' size 10m, 11> '/u01/temp/davidh/redo02.log' size 10m, 12> '/u01/temp/davidh/redo03.log' size 10m; ... channel ORA_AUX_DISK_1: reading from backup piece +FRA/oracs1/backupset/2010_12_05/nnndn0_incremental0_0.752.736917899 ORA-19870: error reading backup piece +FRA/oracs1/backupset/2010_12_05/nnndn0_incremental0_0.752.736917899 ORA-19505: failed to identify file "+FRA/oracs1/backupset/2010_12_05/nnndn0_incremental0_0.752.736917899" ORA-17503: ksfdopn:2 Failed to open file +FRA/oracs1/backupset/2010_12_05/nnndn0_incremental0_0.752.736917899 ORA-15012: ASM file '+FRA/oracs1/backupset/2010_12_05/nnndn0_incremental0_0.752.736917899' does not exis failover to previous backup ... I also tried recover tablespace testg until time 'sysdate-29/24' auxiliary destination '/u01/temp/davidh'; which failed with the same error. But the backup piece physically exists: . oraenv +ASM2 $ asmcmd -p ... ASMCMD [+FRA/oracs1/backupset/2010_12_05] > ls -l +FRA/oracs1/backupset/2010_12_05/nnndn0_incremental0_0.752.736917899 Type Redund Striped Time Sys Name BACKUPSET UNPROT COARSE DEC 09 20:00:00 Y nnndn0_incremental0_0.752.736917899 Besides, RMAN 'crosscheck backup' and 'list backup device type disk', and SqlPlus select * from v$backup_piece all find the piece. Some notes say it could be due to permission of ASM disks. I changed them (/dev/mapper/asm*) to 666 with no success. I use the same user oracle for ASM and DB instance. Thanks for any pointers. Target, catalog, and auxiliary databases are all Oracle 10.2.0.4 on Red Hat Linux 5 x86_64. Yong Huang -- //www.freelists.org/webpage/oracle-l