any difference between DR and business continuity?
any thoughts ?
Hi again Ck,
First of all it is important to recognize that replication (async or sync) is not sufficient as a solution alone. It is just the mechanism to copy data from one site to the other. In itself it doesn't provide any automation or recovery process.
BC would need a combination of sync rep AND a mechanism that "tricks" the hosts / application / OS that the dual datacenters are actually the same so to be able to provide cross datacentre vmotion.
In HDS terms this is "Global-Active Device", based on sync rep. which also requires a third site monitoring to avoid "split brain".
VMware KB: Implementing vSphere Metro Storage Cluster using Hitachi Storage Cluster for VMware vSphere (featuring Hi…
for Oracle, there is a whitepaper:
Rembember... the network here... it is even more complicated than the storage replication.
And remember... there is no such thing as zero downtime
Good question! Even though one can view this quite simply just by using semantics and what the words actually mean, most customers are confused indeed. BC, DR, HA, stretched cluster, off-site backup, ...
Think about the words:
Disaster RECOVERY - recovery per definition a reactive process, meaning one has been "sick" and now trying to get better. So there is IT downtime / error / disaster, on either the application, server, storage system, network, datacentre etc etc.. caused by XYZ types of outage, and now we are trying to RECOVER the services after a period of time (RTO).
Business CONTINUITY - continuity, well business continues - doesn't stop. No downtime. Or if there is downtime, it is so negligible that it has little or no impact on the business / clients / services.
Think about it in VMWare terms:
VMware HA - High availability is in a way DR (disaster recovery) if you consider the failure of one server as a disaster. The server breaks and the VMs are restarted on another host. Reactive process.
VMware Vmotion (and FT in a way), VMs are proactively migrated from host to host (hey this host is gonna fail, lets vmotion it to another host). - Business Continuity.
The same concept can be used in a dual datacentre.
But in short - keep it simple:
DR - downtime and recovery.
BC - no downtime
Than also be quite clear on what actually a DISASTER is, it is different from client to client.
Thanks for your detailed reply
So can I say HUR replication in system replication or true copy (synchronous rep),is used for DR
so there 's RTO and RPO in DR and no such terms in BC right?
So what can be used for BC in terms of HDS solutions
please enlighten more
so much to download i will check these later thanks for everything
agree no such thing zero downtime:)
Retrieving data ...