Dell EqualLogic FS7500 Technical Manual page 14

Figure 4: 6-Array Separated Pool, Block and File I/O Comparison
Since additional IOPS capacity was made available to the NAS volumes (doubling the number of
physical disk spindles from three to six arrays) we observed that the NAS volume performance
increased, but at the same time those volumes now competed for resources with the volumes
belonging to the block clients causing the slight decrease in the block performance.
Taking another look at Figure 2, we see that while the performance of the shared pool was similar to
that of the separated pools for six arrays, separating the arrays into two pools gave us a slight
advantage in total performance. Also, when we examined the average response times (as measured
from the clients), we found it was slightly higher for our block clients when sharing the single storage
pool with file I/O clients as compared to two pools with both sharing file and block I/O. This again is a
result of the file and block volumes now residing on the same physical disks and therefore competing
for the same physical disk resources with file I/O exhibiting better performance. When a new FS7500 is
added to an existing SAN, configuring the FS7500 to use a separate pool prevents it from impacting
the performance of the existing pool.
BP1016 10
Integrating the Dell EqualLogic FS7500 into an Existing SAN