Hi
We are running storage replication offsite (in ASYNC mode) and we are
currently working on replacing it with dataguard. Replicated databases are
around 25TB.
* We are also running ASM, every time we need to add/remove disk from ASM
there is a huge amount of data that needs to be replicated (ASM rebalance).
Initially added double/triple amount of free space didn't last very long,
since the databases grew much faster that expected :)
* We are running in ASYNC, if the replication lags the modifications are
put into replication journal. If this journal gets 80% full or more,
storage starts to throttle down IO on the source luns. From the database
perspective it was a confusing problem to troubleshoot the first time. Also
this problem is quick to arrive when doing ASM rebalance.
Ilmar
On Sat, May 2, 2015 at 5:19 AM, Sanjay Mishra <dmarc-noreply@xxxxxxxxxxxxx>
wrote:
Can anyone share their views on the following on Real practical experience
with the setup in their environment. I had worked with dataguard but never
with Storage Replication for Disaster recover.
Some points for the required environment which can affect or help in
providing or sharing the experience
- Oracle 11g 2-Node RAC setup using ASM on both Primary and DR site
- Database size range from 1-5Tb
- Database has lots of DML activites on daily basis
Questions:
- What is the best option to be used for Disaster Recovery when has to
choose Storage Replication vs DataGuard for RAC setup and if can provide
why you think one preferred over other as per your experience ?
- Does there can be issue if Primary storage or server crashed and
Recovery either failed to start the Datbase on DR or lost some data ?
Keeping in mind that we are working in SYnc Mode.
- Is Storage mirroring can be setup so that both Primary and Remote
storage is almost SYNC like Synchronous Data Giuard Setting ?
- Is it possible that we may loose the DR location and Storage
Replicated environment failed to start ?
- Which one is faster to bring Database live, Storage mirrored DR env
or Dataguard based environment?
- How to go back or switch back to original Primary when you have done
switchover initially to DR location ? In Oracle Dataguard we can go back
using Flashback DB feature and reinstantiate the database
- Any other Pros and Cons for both option as well as any good Link to
be checked.
TIA
Sanjay
