Fastest Database Refresh using Oracle CloneDB

Fastest Database Refresh
using Oracle CloneDB
Sangam 2014 (7th,8th ,9th Nov)
Suvendu
Who am I ?
• 
Lead Database consultant @ Fiberlink-MaaS360 (An IBM Company)
• 
10 years of real-time industry experience (4.5 years with Oracle
corp. metalink support).
• 
OCM , OCP ,RAC ,Oracle Linux Certified.
• 
Technical Blog (www.dbagalaxy.com).
Available Refresh options..
  A refresh can be full database refresh or schema/partial refresh.
  There are several methods for DB refresh /cloning databases .
  Manually copy files and recreate the database.
  EXPDP/IMPDP
  RMAN DUPLICATE - active database.
  RMAN DUPLICATE - backup.
  3rd Party solutions (e.g Snapshots).
  All require copying or restoring files to new location requiring:
  Additional disk space
  Time to perform the copy/import.
Current DB Refresh
Challenges….
§ 
EXPDP/IMPDP process is time consuming. Not an
efficient for big size databases.
§ 
EXPDP/IMPDP feature has lots of bugs which causes
lots of data mismatch/environment mismatch issues.
With every run we find new issues/fixes. That impacts
environment delivery dates.
§ 
Increase in DB environment refresh requests.
§ 
Store usage: We need to further invest in enterprise
storage expansion, licensing.
What is a Clone?
An exact copy of the original.
What is Clonedb?
§ 
In 11.1 Oracle introduced Direct NFS(DNFS) Client .
§ 
11.2.0.2 patch set introduced Clonedb functionality, built on top of DNFS.
§ 
Clonedb uses Write-On-Demand (WOD) technology for clones.
§ 
This is best suited for full database refresh/clone.
Write on demand(W.O.D)
Clone DB 1
Backup
file
Copies
NFS w.o.d
Files
50G
Clone DB 2
Read-only
300GB
NFS w.o.d
Files
10g
Clone DB 3
NFS w.o.d
Files
1G
§ 
Clones use read-only image copies of datafiles as source(Backup).
§ 
Only modified blocks are written to NFS location.
Advantages….
§ 
No extra licensing cost.
§ 
One-time server setup, then repeated cloning is simple,
super-quick (Complete refresh within less than < 10 min)
§ 
Error free method ,exact replica DB of the source DB.
§ 
Dev doesn’t need to spent time on post refresh
issues.Saves two days worth of productive hour of GTS/
DEV.
§ 
Clonedb saves storage space ,with existing infrastructure
we can accommodate 40% more environments.
Demo
Known Issues….
§ 
The script tries to drop default TEMP tablespace .We need to add
temporary tablespace.
§ 
If the source backup is an online backup (not consistent),it may need
media recovery using the archived redo logs.You may get an error during
database open.You can use the following commands to recover.
§ 
ORA-01511: error in renaming log/data files
ORA-01141: error renaming data file x – new file ‘xxxxxxx’ not found
ORA-01110: data file x:xxxxxx
ORA-17515: Creation of clonedb failed using snapshot file xxxxxxxxx
ORA-06512: at “SYS.X$DBMS_DNFS”, line 10
clonedb=true is missing in the clonedb pfile.
This will cause the above errors .If the clonedb parameter is not
updated.
§ 
ORA-01511: error in renaming log/data files
ORA-17513: dNFS package call failed
ORA-06512: at “SYS.X$DBMS_DNFS”, line 10
The log or datafile may be saved in a Local disk.Check if the targetclone datafile locations is not on NFS location.
Limitations….
§ 
Need NFS/DNFS setup.
§ 
Over time if more changed blocks will be written to NFS
location (W-O-D), so space savings will reduce.
§ 
Best suited in One Source –Many Target clone
environment.
§ 
Best suited for short-lived clones used for functional, not
performance testing.
§ 
Fairly new technology with little documentation.
Q&A
Thank You !
Thanks to Kevin and Tim who shared this technology to the community.
http://kevinclosson.wordpress.com/2010/12/23/oracle-database-11g-directnfs-clonedb-feature-part-i/
http://www.oracle-base.com/articles/11g/Clonedb_11gR2.php
MOS: Clone your dNFS Production Database for Testing [ID 1210656.1]
http://docs.oracle.com/cd/E16655_01/server.121/e17636/
create.htm#ADMIN14024

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