Release Notes

19 Analyzing Dell PS Series Storage with SAN Headquarters | TR1050
Table 1 General guidelines for IOPS per disk
Disk type
Random IOPS per disk (8KB I/O size)
7.2K NLSAS
75-90
10K SAS
130-185
15K SAS
180-210
SSD
Depends on I/O size Reads/Writes disk manufacture and model
I/O per disk is dependent on many factors such as speed, interface, disk classification (enterprise or consumer), as well
as the distribution across each individual drive. Although Table 1 is a good reference, care should be taken into
consideration that the table is not used as an absolute. For instance, a 15K disk is capable of speeds over 300 IOPS with
good response time when the data retrieved is not fragmented.
For more advanced analysis, use the following view:
• I/O (all Volumes): Show all volumes and identify the ones with the highest latency, IOPS, MB/s for a possible
move to other resources, for instance, to another pool.
Note: Other views such as Network and Capacity are also necessary for additional details.
2.5.1 SAN HQ poll periods and I/O metrics averages
SAN HQ formats data in a way that can be read through various graphs and tables. The polling period is the sample that
is in the visible view of the charts. To select an interval in the chart, simply click anywhere in the chart. The interval
selected represents any averages which may appear in the tables under the charts or in summary areas next to the
panel.