Test Results And Analysis - Dell EqualLogic FS7500 Technical Manual

5 Test results and analysis

For the combined block and file tests, we observed (see Figure 2) that IOPS increased as additional
clients were added. In the three and four array configurations, performance eventually started to level
off as the pool reached maximum I/O capacity. Adding an additional array to the mix allowed the same
number of clients to gain additional performance and also to scale further before starting to level off
again. Additionally, placing six arrays into a single pool demonstrated a very similar overall
performance profile to placing three arrays each into two separate pools and separating the file and
block I/O from one another.
Figure 2: Combined Block and File IOPS performance
Note: The results provided in this paper are intended for the purpose of comparing the specific
configurations used in our lab environment. The results do not portray the maximum capabilities of any
system, software, or storage.
In Figure 3, the IOPS performance is shown separately for both block and file I/O in the largest
configuration that used a single shared pool (six arrays total). In this example, the proportion of I/O
from file clients (NFS) is nearly double the I/O from block clients. This indicates that the additional
cache memory that is available on the FS7500 contributes to the increased number of I/O completed
by NFS clients. Caching requests locally on the FS7500 means the FS7500 can actually deliver greater
I/O read performance when it already has the requested data in memory or where it performs a
prefetch. In the case of I/O writes, the caching ability of the FS7500 allows it to more efficiently
commit data to the back-end SAN either by coalescing adjacent writes or absorbing bursts of I/O
requests from network clients.
BP1016
Integrating the Dell EqualLogic FS7500 into an Existing SAN
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