I was working with a customer where he was just worried about his flashbackup Backup performance. Here is a quick tip to increase read and write buffer.
How to adjust the FlashBackup read buffer for clients
- Create the following touch file on each client:
- Enter the desired values in the FBU_READBLKS file, as follows:
On the first line of the file, enter an integer value for the read buffer size in blocks for full backups and/or enter the read buffer size in blocks for incremental backups. The default is to read the raw partition in 256 Blocks (131072 bytes/128 KB) during full backups and in 64 blocks (32768 bytes/32 KB) for incremental backups. If changing both values, separate them with a space. The block size is equal to (KB size * 2), or (Number of Bytes / 512).
For example, to set the full backup read buffer to 256 KB and the incremental read buffer to 64 KB, enter the following on the first line of the
file: 512 128
You can use the second line of the file to set the tape record write size, also in blocks. The default is the same size as the read buffer. The first entry on the second line sets the full backup write buffer size, the second value sets the incremental backup write buffer size. If we were to set this at the same values, the file would read altogether as:
Note: Resizing the read buffer for incremental backups can result in a faster backup in some cases, and a slower backup in others. The result depends on such factors as the location of the data to be read, the size of the data to be read relative to the size of the read buffer, and the read characteristics ofthe storage device and the I/O stack. Experimentation may be necessary to achieve the best setting.