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Although storage system workloads differ quantitatively in terms of the transfer sizes, locality, intensity, and distribution of reads vs. writes, the most common applications can be reduced to four common measurement classifications, or workloads:
- Online Transaction Processing (OLTP)
- Workstations
- Web servers
- File severs
By simulating these access patterns, system integrators and administrators can evaluate the performance capabilities for most server and workstation workloads prior to deployment. These workloads, I/O characteristics, and their counterpart applications can be found in the chart below:
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| Measurement |
I/O Characteristics |
Typical Applications |
| OLTP |
Typically 2KB – 16KB request sizes; Read modify, write, verify operations resulting in 2 reads for every write; Primarily random accesses. Large number of concurrent requests. |
Databases (SAP, Oracle, SQL), Online Transaction Servers |
| File Server |
Moderate distribution of request sizes from 4KB to 64KB, however 4KB and 64KB comprise 70% of requests; Primarily random; Generally 4 reads for every write operation. Large number of concurrent requests during peak operational periods. |
File and Printer Servers, e-mail (Exchange, Notes), Decision Support Systems |
| Web Server |
Wide distribution of request sizes from 512 bytes to 512KB; Primarily random accesses; Large number of concurrent requests during peak operational periods |
Web Services, Blogs, RSS Feeds, Shopping Carts, Search Engines, Storage Services |
| Workstations |
Primarily small to medium request sizes; 80% sequential and 20% random; Generally 4 reads for every write operation. 1-4 concurrent requests. |
Business Productivity, Scientific/Engineering Applications | |