remove srdf

Yes

You can remove pairs online, without affecting prod hosts.

Rob sometime I'm surprised it works ..

Great stuff, these EMC disks thingies. Data is being preserved when you do stuff on the box they're in.

One little caveat - if you are only removing a single device from the SRDF setup depending on the mode you are running (if you are using either Async or sync modes) you will need to stop the entire RDF group while you make the change.

Still no outage or impact to your production host, just realize that you take down your entire DR replication setup while you do this (very minimal) work.

Not a big deal, just something to consider. If you are removing all of the volumes involved in the RDF group then nothing to even consider.

Just to add a little to what you said ..

1) when you have a RDFgroup running in SRDF/S (synch) mode you can split (and delete) any single pair .. without affecting consistency of all other pairs.

2) when you have a RDF group running in either ACP_DISK or ACP_MEM mode you can split (and delete) any single pair (again without affecting other pairs and their in-consistency).

3) when you have a RDF group running in SRDF/A (async) mode you can't split a single device. You have to disable SRDF/A (and turn back to SRDF/S or ACP_DISK mode) and split/deletepair desired pair. After deleting unneeded pair you can resume SRDF/A (set mode async) and enable consistency protection (symrdf -g xxx enable).

4) when you have complex replica with both SRDF/A and SRDF/S (in either concurrent or cascaded style) or even STAR, the easy answer is "it depends" however above mentioned general rules still apply.