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2.7
Optimizing Switch Performance with SATA Drives
Due to the nature of SATA drives the performance of the SAS bus will vary depending on the SATA IOs rate.
During domain discovery the SATA drives will stop the IO stream for 1000 milliseconds. This interrupt of the IO
stream will decrease the overall bandwidth. To minimize the impact to the IO bandwidth it is recommended to
either turn off switch discovery or change the switch discovery polling time. Turning off the switch discovery
does not affect the SAS domain discovery when a change occurs on the SAS domain. The domain changes will be
reflected back to the OS and handled correctly.
When the switch discovery is turn off any changes to the SAS domain will not be seen by the SDM GUI. To see the
changes the switch discovery needs to be enabled through the SDM GUI. Normal discovery will still occur
updating all the servers connected to the domain. The other option is to change the switch polling time to
minimize the effect of the SATA delay on the bandwidth. This document will explain how to turn off the switch
discovery or change the switch polling time for discovery.
The SDM GUI will be used to change the switch settings to either turn off the switch discovery of change the
switch polling time.
Option 1 Disable the switch discovery polling
.
Click on the “Server” menu, then “Configure”, then SDM Settings” (see figure below).