Set the matching of DB2 and AIX strip technology to improve I/O performance (1)

This article mainly describes how to correctly set the matching of the DB2 database and the AIX strip technology to improve the I/O performance. We all know the strip technology, it is a widely used I/O load balancing technology that can greatly improve I/O performance without additional hardware investment.

However, in an environment where such technology is used, only the I/O processing of databases and operating systems is well planned and configured to match the striping technology, in order to achieve the best I/O performance. This article takes the DB2 database and AIX operating system as an example to introduce how to plan and set relevant content.

The strip technology is a widely used I/O load balancing technology that can greatly improve I/O performance without additional hardware investment. However, in an environment where such technology is used, only the I/O processing of databases and operating systems is well planned and configured to match the striping technology, in order to achieve the best I/O performance. This article takes the DB2 database and AIX operating system as an example to introduce how to plan and set relevant content.

We will introduce the following aspects:

Introduction to strip technology

Reasonably plan and set DB2 database strip parameters in DB2

Reasonably plan and set strip-related parameters in AIX

Summary

Introduction to strip technology

Brief introduction and application of strip technology

When multiple processes access a disk at the same time, a disk conflict may occur. Most disk systems have limits on the number of I/O operations per second (IOPS) and the amount of data transmitted per second (TPS. When these restrictions are met, the process that needs to access the disk needs to wait. This is the so-called disk conflict.

Avoiding disk conflicts is an important goal to optimize I/O performance. I/O performance optimization is significantly different from other resources such as CPU and memory optimization, the most effective means of I/O optimization is to maximize the balance of I/O. In this case, the I/O access load on a hotspot disk needs to be shared to other relatively idle disks, that is, I/O load balancing.

Prior to the emergence of some mature Disk Load Balancing technologies, DBA needs to understand and predict the I/O load of each system, manually configure each data to different storage locations to share the I/O load to achieve load balancing.

The strip technology is a technology that automatically distributes I/O loads to multiple physical disks, the strip technology divides a piece of continuous data into many small parts and stores them on different disks. This allows multiple processes to access multiple different parts of data at the same time without causing disk conflicts, in addition, you can obtain the maximum I/O Parallel capability when you need to perform sequential access to such data to achieve excellent performance.

Many operating systems, disk equipment suppliers, and various third-party software can be striped. Through striping, DBA can easily achieve I/O Load Balancing without manual configuration.

Figure 1 describes the distribution of continuous data without band-based processing, and figure 2 describes the distribution of continuous data that has been processed by band-based processing, we can find that in Figure 2, the maximum concurrency is available for reading and writing continuous data.

Figure 1. Continuous data without strip Processing

Figure 2. Continuous data that has been striped

Because of its superior performance in I/O performance, the band-based technology is involved in multiple layers or platforms in the computing environment where the application system is located, for example, the operating system and the storage system may both use the strip technology. Shows the I/O structure of these two layers.

Figure 3. Operating System and storage system I/O structure

At the operating system level, we can use software strip such as lvm lv strip to achieve strip technology) or hardware strip such as RAID ). At the storage system level, most products on the market currently provide various strip technologies, such as RAID ).