Hi,

With the Release of solution enabler 7.2 and micro code 5874 and there is intruduction of Dynamic RDF which means , we need  no more suspending the srdf session. We can add the device pairs to the existing rdfg group or we can use movepair option from moving from one rdfg to other. The standard practice use is to add the r1r2 pair to the temprory rdfg group and make them synch and then add them to the rdfg group where it is intended to go.

thanks

Hi,

We dont have Vmax in our environment and we have only DMX-4.  Can you explain me the benefits of introducing movepair operation in our existing SRDF environment in 5773 microcode and SYMCLI version 6.5.2? 

Thanks

Kannadasan

HI,

I understand you have SYMCLI version 6.5.3,i think its time for you to consider an upgrade to 7.1 or higher. With 5773 code and SE version 7.0 and higher, we have introduced cons_exempt flag while using the createpair and movepair (if you have consistency enabled on RA group and want to add device pair to it without disabling the consistency).

You are looking for the benefit of movepair? With movepair, you can move the device pairs from one ra group to another. I dont see any othr benefit other than this.

regards,

Saurabh

With DMX4 and older symcli, you have to convert the whole RDFG to SYNC or ACP (Adaptive Copy Disk or Memory mode) before changing number of pairs on the link. Obviously this means that the whole RDFG have to stay in ACP or SYNC untill the new devices reach appropriate state. While the group is operating in SYNC you may have performance impact on your R1 hosts. With ACP_* mode you are exposed at data-loss in case of a real failover (while in ACP mode).

Using a temporary RDFG reduces the exposure since you can leave the main RDFG in ASYNC and use the temporary RDFG to sync the new devices. When the new devices are at the appropriate state (little if no invalids) you quickly put main RDFG in ACP, move devices from temp to main RDFG and put again the main RDFG in ASYNC within minutes instead of hours.

So the cons_exempt flag be used with DMX4 ? or is it only with vmax ? I know its a feature in the new micro code but would like to know if its for specific hardware.

Sure, it can be used by dmx4 , all what you will need enginuity 5773.150  and above as well as SE 7.0 or higher.

We are seeing some issues when I started this new flag. The devices in temporary group are suspended but were in adaptive copy mode. I did a movepair using the –cons_exempt flag to the required async rdf group and did a resume and after couple of minutes it was in consistent state. But after presenting the device to the host the next day started seeing some issues with the rdf group where all devices went into SyncInProg state and consistency is False even though all devices are in async & consistency enabled. Any reasons why ?

were you able to find what happened here?. Movepair is one of the commands i would like to experiment  in real life ,  and sharing your experence might help me too