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DR help

Waqar Razi
Regular Advisor

DR help

We have a mirror of data on storage and as part of our DR practise, we are breaking up the mirror and then attaching the split mirror to the other machine by installing OS first on it using Ignite.

Can some one please give me directions or steps to accomplish this task.

Thanks in advance.
Steven E. Protter
Exalted Contributor

Re: DR help


The steps depend on the type of data stage you use.

You do not reveal storage configuration, or even the OS Version.

In a general sense, once you split the mirror on the data, you can back up the mirror any way you want. fbackup will work.

System recovery using Ignite:

Steven E Protter
Owner of ISN Corporation
Rita C Workman
Honored Contributor

Re: DR help


I see by your previous postings your storage is EMC. I see something else too.

You can search these Forums because many of us have answered similar questions.

But the best answer is to get the manual and open it and start reading. That will help you significantly, since EMC offers products that will do exactly what you are trying to accomplish. I know - I have EMC too. The best teacher is the vendors manuals.

Yaniv Valik
Occasional Advisor

Re: DR help

Hello Wagar,

If you're using EMC storage, documentation on powerlink would be a good start, but not enough.

To ensure data will be recoverable, you will also need to review database / system recovery documentation (Oracle, SQL Server, DB2, Microsoft, Linux, etc). There are different procedures for the various vendors, versions, modes, etc.

For example, if you break the mirror without db cold backup or without first inserting the database to hot backup mode / IO suspension mode, data on the DR side may be inconsistent and unusable.

There are many other guidelines, recommendations and best practices as it relates to data completeness and consistency on DR, recoverability, meeting RPO / RTO goals, etc. Perhaps if you can provide more details on the environment, we can give you more specific advices.

Best Regards,
Rita C Workman
Honored Contributor

Re: DR help


Yaniv has given some great points that you absolutely need to consider and work into any plan you make.

DR practice tends to imply your looking for a way to rebuild your sites remotely. That takes on another flavor and more complexity, and along with Yaniv, many more points to consider.

If your just trying to mount things up on another box within your lan, then you might consider EMC's Timefinder. It syncs up a mirror disk, splits it off, and you can then mount it up on another box. That is saying it simply - but they provide great tools and documentation. By using your vg mapfiles, you just create on the new box using the mapfiles (with the mirror disk only), then sync/split/fsck & mount.

But nothing beats a good book!
Mel Burslan
Honored Contributor

Re: DR help

Depending on your DR strategy, and the connectivity between the main data center and the DR data center, you might have other options. As a matter of fact, if you are talking about a DR site far away, mirroring disk volumes over WAN, is not a very easy thing to do and cost you a hefty performance penalty on your main data center side. If you are using EMC storage, and you have something like OC-3 connectivity to your DR site from your main data center, it is advisable you talk to EMC about their SRDF and/or TimeFinder utilities. (I may be wrong about the names/spelling but they will know what you are talking about when you mention remote DR site) They are not free or cheap but DR is not a practice to be taken lightly anyway.

Good luck.
UNIX because I majored in cryptology...