What is SAN Storage QoS?

 

Quality of Service: Is one of the feautre which is use to prioritize the I/O Traffic from host to storage LUN via; SAN switches.

 

With respect to Broacade SAN switches to implement QoS feature on SAN.

 

Quality of Service (QoS): Allocates bandwidth in the event of congestion to 

expedite high-priority traffic and keep all traffic flowing. Organizations use 

existing zoning to easily assign traffic flows a high, medium (default), or low 

priority. If congestion occurs, high-priority zones automatically are assigned60 

percent of the available bandwidth, medium30 percent, and low10 percent.

 

QoS zones

QoS enables the setting of traffic priorities between specific hosts and targets. Prioritization is

accomplished by the use of QoS zones, which will appear as normal zones. When creating a QoS zone

they must be created using WWN notation and all normal zoning rules apply. To distinguish QoS zones

from normal zones, special prefixes are used in the zone names:

- QOSH_ to set high priority

- QOSL_ to set low priority

Default setting is medium priority and is used when no QoS zones are specified or when QoS cannot be

enforced.

QoS is the process through which we define and prioritize the I/O availability to an application/server on a LUN.