第一行注释的是之前我配置的NFS挂载，而实际如果要存放数据文件，则需要按照上面提到的MOS文档进行配置，也就是第二行内容。
修改完重新挂载/public, 再次测试backup as copy，已经可以正常备份了。
RMAN> backup as copy datafile
6 format '/public/backup/oradb23/%u.dbf';
Starting backup at
25-MAR-
17
using channel ORA_DISK_1
channel ORA_DISK_1: starting datafile copy
input datafile
file number=
00006 name=+
DATA/jyzhao/datafile/dbs_d_jingyu
.268.937515173
output
file name=/
public/backup/oradb23/7s022f8.dbf tag=TAG20170325T214928 RECID=
16 STAMP=
939592197
channel ORA_DISK_1: datafile copy complete, elapsed time:
00:
00:
35
Finished backup at
25-MAR-
17
Starting Control
File and SPFILE Autobackup at
25-MAR-
17
piece handle=/
public/backup/oradb23/c-
2520969382-
20170325-
03 comment=
NONE
Finished Control
File and SPFILE Autobackup at
25-MAR-
17
至此，就可以正常backup as copy到我的NAS设备中了。
