Improving the performance of single instance Oracle on file systems, January 2008

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Figure 4 Oracle 9.2.0.7 – The loss in performance when ODM is not present
Expressed as a percentage drop relative to raw volumes on VxVM, about 94% of transactions are
lost. Doing the same calculation but relative to VxFS/VxVM+ODM, about 92% of transactions are
lost.
With greater partitioning and many more data files, the loss would likely not be as dramatic,
although implementing such partitioning would tend to negate the benefits in manageability that the
use of a file system can bring.
Experiment 4: Comparing two common LVM configurations to Online JFS with ODM enabled
Some customers use raw volumes on LVM; others have Online JFS on LVM volumes. This experiment
compares these LVM configurations with the results obtained in Experiment 2.
For Experiment 4, two sets of results were obtained: one for raw-on-LVM and another for Online JFS
configured on LVM volumes.
Figure 5 shows the TPM results for these configurations and two percentage comparisons expressed
relative to the numbers measured for the ODM case.
For a workload of 80 clients, a 13-fold improvement in performance (see comparison (a) in Figure 5)
is measured for Online JFS on LVM. There is a 10-12% loss in performance for the ODM
configuration relative to the raw-on-LVM volume configuration.