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12 BP1038| Best Practices and Guidelines for Integrating the Dell EqualLogic FS7600 and FS7610 into an Existing SAN
6 Test methodology
For the block I/O testing, Vdbench was configured to read and write from RAW disks (disks without a file
system). A working file size of 99 GB was used for the block clients to use close to the full capacity of the
attached volume and also to minimize the effect of client-side caching in the VM.
For the file I/O tests, initially tests were run against both CIFS and NFS mount points. The results were
similar, so for the combined block and file testing, only NFS mount points were used for the file clients.
Vdbench was configured to create a directory structure that was three directories wide and two
directories deep. Each bottom-level directory had sixteen 50 MB files which resulted in a total working set
of about 5 GB for each client. Before running the workload test scripts, a separate formatting script was
run to create the file and directory structure on the file system.
Each test client used a workload of random I/O consisting of 70% read and 30% write operations. Each test
was run with an I/O request size of 4K, 8K, 16K, 32K, 64K, 128K, and 256K. Eight Vdbench worker threads
were run for each client VM. This resulted in a client that generated more I/O than a typical user might,
however it minimized the number of overall client systems required to generate a significant workload on
the SAN. Each workload was run for 30 minutes, and then the results were collected from each Vdbench
client and from a separate management system that was running SAN HQ.