EMC SRDF Synchronous
EMC's SRDF/S is a synchronous copy services solution, supported throughout the Symmetrix and DMX model ranges.
With a SRDF/S, each write operation to the 'primary' controller will be replicated real-time to a secondary controller in another location. The primary controller will only complete its write operation after the secondary controller has acknowledged successful receipt of the data.
Synchronous protocols like SRDF/S introduce overhead for the primary disk subsystem controllers, and introduce a delay for each write operation. The extra time needed increases as longer distances are involved, limiting synchronous solutions to about 300 kilometers over Fibre.
Because of this it is important to monitor the response time impact of SRDF/S. As the number of links between the primary and secondary controllers determine how much bandwidth can be handled, it is also important to know how many MBytes are written during the peak workload periods.
EMC has dedicated a section of their web site to SRDF:
You can also download the SRDF data sheet.
In our products
SRDF/S Planning
Use IntelliMagic Vision for z/Series to:
- Identify the bandwidth required between your EMC subsystems
- Identify whether there are very busy volumes that might not be able to tolerate the additional delay inherent to synchronous copy services solutions.
SRDF/S Monitoring
Use IntelliMagic Vision for z/Series to:
- To track the growth of the bandwidth requirements
- Shows the impact of SRDF/S on the disk response time