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DB2 UDB for z/OS Version 8 Performance Topics - IBM Redbooks

DB2 UDB for z/OS Version 8 Performance Topics - IBM Redbooks

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Figure 5-1 FRBACKUP PREPARE elapsed time vs. #volumes in the copy pool<br />

Since the time to prepare the replication environment will increase with the number of<br />

volumes in the copy pool, this action should be executed be<strong>for</strong>e initiating the real backup.<br />

Figure 5-2 shows the measurement results increasing the number of versions.<br />

sec.<br />

sec.<br />

300<br />

250<br />

200<br />

150<br />

100<br />

50<br />

0<br />

200<br />

150<br />

100<br />

Figure 5-2 FRBACKUP PREPARE elapsed time vs.#versions <strong>for</strong> 67 volume copy pool<br />

Increasing the number of versions means increasing the number of target volumes, this<br />

significantly increases the time to prepare the replication environment. Again we recommend<br />

222 <strong>DB2</strong> <strong>UDB</strong> <strong>for</strong> z/<strong>OS</strong> <strong>Version</strong> 8 Per<strong>for</strong>mance <strong>Topics</strong><br />

50<br />

0<br />

FRBACKUP PREPARE measurements<br />

1<br />

Elapsed Time <strong>for</strong> PREPARE<br />

8<br />

171<br />

13 67<br />

# of Vols<br />

195<br />

One <strong>Version</strong><br />

FRBACKUP PREPARE measurements…<br />

8<br />

Elapsed Time <strong>for</strong> PREPARE<br />

96<br />

265<br />

1 2 3<br />

# of <strong>Version</strong>s<br />

67-Vol

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