BAR_XFER_BUF_SIZE (IDS)

onconfig.std value

31

units

page size

range of values

1 to 15 pages when the PAGESIZE is 4 kilobytes
1 to 31 when the PAGESIZE is 2 kilobytes

The maximum buffer size is 64 kilobytes, so BAR_XFER_BUF_SIZE * pagesize <= 64 kilobytes

takes effect

When onbar starts

The BAR_XFER_BUF_SIZE configuration parameter specifies the size of each transfer buffer. The database server passes the buffer to ON–Bar and the storage manager. To calculate the size of the transfer buffer in a storage space or logical-log backup, use the following formula:

transfer buffers = BAR_XFER_BUF_SIZE * pagesize

Where pagesize is the largest page size used by any of the dbspaces that are backed up.

To calculate how much memory the database server needs, use the following formula:

memory = (BAR_XFER_BUF_SIZE * PAGESIZE) + 500 

The extra 500 bytes is for overhead. For example, if BAR_XFER_BUF_SIZE is 15, the transfer buffer should be 61,940 bytes.