DB2 Version 9.7 for Linux, UNIX, and Windows

Optimizing backup performance

When you perform a backup operation, DB2® will automatically choose an optimal value for the number of buffers, the buffer size and the parallelism settings. The values are based on the amount of utility heap memory available, the number of processors available, and the database configuration. Therefore, depending on the amount of storage available on your system, you should consider allocating more memory by increasing the UTIL_HEAP_SZ configuration parameter. The objective is to minimize the time it takes to complete a backup operation. Unless you explicitly enter a value for the following BACKUP DATABASE command parameters, DB2 will select one for them:

If the number of buffers and the buffer size are not specified, resulting in DB2 setting the values, it should have minimal effect on large databases. However, for small databases, it can cause a large percentage increase in backup image size. Even if the last data buffer written to disk contains little data, the full buffer is written to the image anyway. In a small database, this means that a considerable percentage of the image size might be empty.

You can also choose to do any of the following to reduce the amount of time required to complete a backup operation: