using SRDF/AR for DR

[Hanry Zhou]

We are thinking of using SRDF/AR solution to replicate data on remote site. Now, we are considering to use a development server on the remote site for DR server. In another words, in normal time, the server is used for development work, however, in a disaster time, we use the server as the disaster recovery production server.

With this approach, I have a few questions:
1. how do we reflect the prod server name on the remote site? if we change DNS entry, that will take ours to populate DNS data.

2. how do we solve the issues of developement volume groups, and DR productions volume groups? Do we need to mount prod. vg /file systems in the normal time?

Please advice,

[Geoff Wild]

Okay - we do basically what you want.

For #1:

We setup DNS ahead of time, we have a QA system which is our Prod DR system.
DNS name for Prod: ZPR
DNS name for QA: ZQA
DNS name for DR: ZPRDR

In a real disaster - we would update DNS to reflect where prod is - for testing, we use zprdr. (BTW - DNS on unix take effect immediately - and takes about 30 minutes in the Windows world).

For #2

That depends on how much money you have and how much disk you have.

What we do:

zpr is 1.8 TB
zqa is also 1.8 TB (identical)

zpr is mirrored and has bcv's.
Then there are the local and remote rdf pairs. Then there are the remote bcv's.

The remote bcv's are associated with the standards of zqa.

In a dr (or test) we blow away the qa system by doing a bcv restore on the remote side.

We can do this as we have our QA system disk layout identical to PROD.

When we finish the test, we rename the DR back to QA - in essence we just refreshed our QA system with the latest PROD data.

At any given moment, we have 6 copies of production on disk!

If you can afford it, you could have another copy at the remote site - then unmount QA (in your case dev) then mount up PROD.

Rgds...Geoff

[Hanry Zhou]

Sorry, I don't quite understand you.

Is QA system is same as DR system?
Can I use the same server for both DR, and QA(in my case, development)?
when you say "restore bcv's to remote site", what does that mean? restore bcv's on QA to DR servers?