Clonedb: The quick and easy cloning solution you never knew you had. Tim Hall Oracle ACE Director Oracle ACE of the Year 2006 OakTable Network OCP DBA (7, 8, 8i, 9i, 10g, 11g) OCP Advanced PL/SQL Developer Oracle Database: SQL Certified Expert http://www.oracle-base.com Books Oracle PL/SQL Tuning Oracle Job Scheduling http://www.oracle-base.com

Clonedb: The quick and easy cloning solution you never knew you had. What is a clone? Why clone databases? How do we clone databases? What is Clonedb? Demo of Clonedb Considerations http://www.oracle-base.com

What is a Clone? An exact copy of the original. http://www.oracle-base.com

Why Clone Databases? Set up new databases as copies of existing ones. Data refresh for development and test environments from production. Test backup & recovery. Create standby databases. Recover lost data or objects (where flashback is not appropriate). http://www.oracle-base.com

How do we Clone Databases? There are already several methods for cloning databases including: Manually copy files and recreate the database. RMAN DUPLICATE - active database (11g). RMAN DUPLICATE - backup. 3rd Party solutions. All require copying or restoring files to new location requiring: Additional disk space. Time to perform the copy. Clonedb makes cloning quicker and saves space. http://www.oracle-base.com

What is Clonedb? In 11.1 Oracle added the Direct NFS Client to the database. The 11.2.0.2 patch set introduced Clonedb functionality, built on top of Direct NFS. Clonedb uses Copy-On-Write (COW) technology for clones. http://www.oracle-base.com

Copy-On-Write (COW) NFS C.O.W. Files Clone Database Datafile Image Copies NFS C.O.W. Files Clone Database Clones use read-only image copies of datafiles as source. Only modified blocks are written to NFS location. http://www.oracle-base.com

What is Clonedb? (continued) Clonedb saves space when you have multiple clones as they can all reference the same source files. One-time server setup, then repeated cloning is super-quick. Only documented in My Oracle Support (MOS) Note 1210656.1 http://www.oracle-base.com

Demo (cleanup.sql) http://www.oracle-base.com

NFS Server Setup Create a directory to hold the copy-on-write files. # mkdir -p /u01/nfs-share Append the share into the “/etc/exports” file. /u01/nfs-share *(rw,sync,no_wdelay,insecure, insecure_locks,no_root_squash) Make sure the NFS service is turned on. # chkconfig nfs on # service nfs restart http://www.oracle-base.com

Production Backup Make an image copy backup of the database. The copy can be placed on a share (CIFS/NFS) or copied to the local file system of the server running the clone. configure controlfile autobackup off; sql 'alter database begin backup'; run { set nocfau; backup as copy database format ’/u01/backups/prod/%U’; } sql 'alter database end backup'; (backup.sh) http://www.oracle-base.com

Copy Production PFILE Take a copy of the production PFILE by running the following command as the SYS user. (create_pfile.sh) CREATE PFILE='/u01/backups/prod/initTEST.ora' FROM SPFILE; Edit the PFILE, changing all references to the original SID and database name. http://www.oracle-base.com

Clonedb Server Setup Turn on Direct NFS for the ORACLE_HOME on the clonedb server. (dnfs.sh) $ cd $ORACLE_HOME/rdbms/lib $ make -f ins_rdbms.mk dnfs_on Make the necessary directories for the NFS mount and to support the instance. (directories.sh) http://www.oracle-base.com

NFS Mount Add the NFS mount to the “/etc/fstab” file, along with any other necessary shares. nas1:/u01/nfs-share /u01/copy-on-write nfs rw,bg,hard,nointr,tcp,vers=3,timeo=600, rsize=32768,wsize=32768,actimeo=0 0 0 Mount the copy-on-write location. # mount /u01/copy-on-write http://www.oracle-base.com

Clone the database Set the required environment variables and run the “clone.pl” script. (create_clone_script.sh) Review the contents of the generated files. Run the files to create the clone. (create_clone.sh) http://www.oracle-base.com

Clone the database If you did hot backup you may need to recover database. SQL> RECOVER DATABASE USING BACKUP CONTROLFILE UNTIL CANCEL; SQL> ALTER DATABASE OPEN RESETLOGS; Make sure the TEMP tablespace has been handled properly. (manage_temp.sql) Check the database. (datafiles.sql) http://www.oracle-base.com

Considerations - Performance Copy-On-Write location is NFS. Is that an issue for you? If a cloned database is to be used for performance testing, do you really want a different storage technology in the mix? Possible performance improvements on the horizon? http://www.oracle-base.com

Considerations - Space Savings Over time more changed blocks will be written to NFS location, so space savings will reduce. Only works with image copies. If you don’t use image copy backups how much space are you really saving? http://www.oracle-base.com

Considerations - Others Very little documentation. Very new. http://www.oracle-base.com

Where would I use it? For short-lived clones used for functional, not performance testing. To test backups. To recover lost objects. http://www.oracle-base.com

Where would I NOT use it? Setting up long-term clones. For clones used for performance testing. For setting up a standby database. http://www.oracle-base.com

Summary Very quick cloning. Potential for big space savings. Need to be on at least 11.2.0.2. Need to use NFS for COW location. http://www.oracle-base.com

The End… Download slides and example code at: http://www.oracle-base.com/workshops Article: http://www.oracle-base.com/articles/11g/Clonedb_11gR2.php http://www.oracle-base.com