rman备份到netapp nfs后，开启SIS删除重复数据块以节省空间。
[@more@]1、修改exports,两种方式
（1）将原来的内容rdfile /etc/exports读出来然后复制用wrfile /etc/exports 写,如/vol/vol1 -sec=sys,rw=192.168.168.*:192.168.168*,root=192.168.168.*:192.168.168.*,nosuid
也可以用192.168.168.0/24将一个网段写进去。
（2）用exportfs命令
exportfs –i0 rw=192.168.168.*:192.168.168*,root=192.168.168.*:192.168.168.*,nosuid /vol/vol1
exportfs –w /etc/exports (将正在运行的exprot写入exports)
2、重启NFS server
Exportfs –a
Exportfs -r
Nfs off nfs on
3、在10gR2的RMAN备份到NFS上时，会出现这个错
Backup of 10g NFS database fails with RMAN error "ORA-27054: NFS file system where the file is created or resides is not mounted with correct options"
Follow the directions in Oracle Metalink Note 387700.1:
Execute the following SQL statement and restart the target database in SQL*Plus as the sys user:
SQL> ALTER SYSTEM SET EVENT='10298 trace name context forever, level 32' SCOPE=spfile;
SQL> SHUTDOWN IMMEDIATE
SQL> STARTUP
BUG: http://forums.oracle.com/forums/thread.jspa?messageID=2508573
To support:
Please note - it is possible to disable the NFS checks in
10.2 by setting event 10298 at level 32.
eg: Add this to the init.ora
#disallow MOUNT POINT checks
event="10298 trace name context forever, level 32"
This will disable the NFS mount checks allowing you to use
any mounts options but then the onus is on yourself to ensure
that the mount options used for each disk are correct
for the use that they are to be put to.
开始测试：
nohup /home/oracle/worksh/rmanbak_old.sh DB > /tmp/rmanback.log 2>&1 &
查看备份后的大小
fas3050> df -h vol1
Filesystem total used avail capacity Mounted on
/vol/vol1/ 1600GB 518GB 1081GB 32% /vol/vol1/
/vol/vol1/.snapshot 400GB 30MB 399GB 0% /vol/vol1/.snapsho
开启重复删除功能
fas3050> sis on /vol/vol1
SIS for "/vol/vol1" is enabled.
Already existing data could be processed by running "sis start -s /vol/vol1".
fas3050> sis start -s /vol/vol1
The file system will be scanned to process existing data in /vol/vol1.
This operation may initialize related existing metafiles.
Are you sure you want to proceed with scan (y/n)? y
Mon Jun 30 17:56:13 CST [wafl.scan.start:info]: Starting SIS volume scan on volume vol1.
The SIS operation for "/vol/vol1" is started.
fas3050> sis status
Path State Status Progress
/vol/vol1 Enabled Active 117 GB Scanned
fas3050> sis status
Path State Status Progress
/vol/vol1 Enabled Idle Idle for 00:05:02
完成后查看节省的空间大小
fas3050> df -sh vol1
Filesystem used saved %saved
/vol/vol1/ 436GB 86GB 17%