Clarification for buffers versus sqlbuffers with the Data Protection SQL

Answer

The SQLBuffers and Data Protection Buffers are the number of buffers in memory that is defined for holding data during a Data Protection for SQL backup. The SQLBufferSize and the Data Protection BufferSize are values for the amount of memory that will be allocated to each of these buffers.

The SQLBufferSize and Buffersize can be looked at as the size of the bucket that will hold the data.
Each buffer (or bucket) will sit in memory to collect data for the backup. After the bucket is full, then the data will be sent:

• For the SQLBuffer, this is allocated within SQL Server memory for the data that is passed to the Data Protection client.
• For the Data Protection Buffer, this is used to pass the data to the Tivoli Storage Manager API for transport to the Tivoli Storage Manager Server.

The SQLBuffers parameter has a default value of 0 which means that the SQL Server will decide how many buffers it can/will allocate.
If the SQLBuffer is set to a value of one, then the SQL Server will only use one buffer, filling this single "bucket" and then waiting until it is emptied before more data can be processed. There are usually several buffers allocated. This provides the functionality for when one buffer is full and this is in the process of being sent, the backup processing does not have to wait until the buffer is emptied before it can continue. This allow for the process to immediately work with the next available buffer.

If the SQLBuffer was set to one (or a very low value), this would use less memory as less buffers are allocated. Lowering the values can degrade performance, but in certain cases where the SQL Server has memory or resource issues, this should help to lower the memory needs for the SQL Server backup using the Data Protection client. Microsoft support should be contacted to determine why the SQL Server is low on memory/resources.