EMC Backup and Recovery for Oracle 11g OLTP Enabled by EMC ...

Chapter 6: Testing and Validation
The backup begins at data point 4. Because the clone metaLUNs are made up of a
separate and independent group of disks there is no additional overhead on the
production LUNs.
Pointer 5: Backup completes.
Deduplication The following images show the data stored on the DD880 after five weeks running
the backup schedule. The backup schedule consisted of RMAN level 0 (full) backups
only. That is, Level 0 backups on the weekend and RMAN level 0 backups Monday
through Thursday. The database daily change rate is ≈ 2 percent. However, because
the archived log files were also backed up, the change rate observed during
incremental backups was actually much higher, closer to 10 percent.
By eliminating redundant data segments, the Data Domain system allows many
more backups to be stored and managed than would normally be possible for a
traditional storage server. While completely new data has to be written to disk
whenever discovered, the variable-length segment deduplication capability of the
Data Domain system makes finding identical segments extremely efficient.
The storage saving graph above shows the data written to the DD880 over a fiveweek
period. The backup cycle consisted of all RMAN level 0 (full) backups.
Line 1: "Data Written" shows that approximately 24 TB was backed up over the
five-week period.
Line 2: "Data Stored" tracks the unique data actually stored on the DD880 after
inline deduplication. The remaining redundant data was eliminated. This results
in a net saving of 92 percent of storage space required over the five-week
period.
Line 3: "% Reduction" shows the storage saving as a percentage over the fiveweek
period. This results in a deduplication factor of 13:1.
EMC Backup and Recovery for Oracle 11g OLTP Enabled by EMC CLARiiON, EMC Data Domain, EMC NetWorker,
and Oracle Recovery Manager using NFS Proven Solution Guide
69