IBM TotalStorage DS6000 Series: Performance Monitoring and Tuning

Chapter 12. Understanding your workload 411

transfers (4 KB, 8 KB, 16 KB, and 32 KB), 50/50 and 70/30 R/W ratios, and a random

DBMS.

These workload categories are summarized in Table 12-2, and the common applications that

can be found at any installation are classified following this categorization.

Table 12-2 Application workload types

12.3.1 General file serving

This application type consists of many users, running many different applications, all with

varying file access sizes and mixtures of read/write ratios, all occurring simultaneously.

Applications could include file server, LAN storage, disk arrays, and even Internet/intranet

servers. There is no standard profile here, other than the ‘chaos’ principle of file access. This

application is considered here, because this profile covers almost all transfer sizes and R/W

ratios.

12.3.2 Online transaction processing

This application category typically has many users, all accessing the same disk storage

subsystem and a common set of files. The file access typically is under control of a DBMS

and each user may be working on the same or unrelated activities. The I/O requests are

typically spread across many files, therefore the file sizes are typically small and randomly

accessed. Typical applications consist of a network file server or disk subsystem being

accessed by a sales department entering order information.

12.3.3 Data mining

Databases are the repository of most data, and every time information is needed some type

of database is accessed. Data mining is the process of extracting valid, previously unknown

and ultimately comprehensive information from large databases and using it to make crucial

business decisions. This application category consists of a number of different operations,

Category Application Read/write ratio I/O size Access type

4 General file serving All simultaneously 4 KB - 32 KB Random and

sequential

4 Online transaction

processing

50/50, 70/30 4 KB, 8 KB Random

4 Batch update 50/50 16 KB, 32 KB Random and

sequential

1 Data mining 100/0 32 KB, 64 KB, or larger Mainly sequential,

some random

1 Video on demand 100/0 64 KB or larger Sequential

2 Data warehousing 100/0, 70/30, 50/50 64 KB or larger Mainly sequential,

random easier

2 Engineering and

scientific

100/0, 0/100, 70/30,

50/50

64 KB or larger Sequential

3 Digital video editing 100/0, 0/100, 50/50 32 KB, 64 KB Sequential

3 Image processing 100/0, 0/100, 50/50 16 KB, 32 KB, 64 KB Sequential

4 Batch update 50/50 16 KB, 32 KB Random and sequential