Pausing CRR Replication

Question

When we put some CRR groups into direct access mode, and that copy gets paused, where are the changes being tracked?  Also, is there a limit to the amount of change it will keep track so that a full sweep isnt required once we tear down the group/lun that was in direct access.  we are running version 4.1.

Idan · Accepted Answer

Hi,

1. While in direct image access mode, the changes are marked as a bitmap in the journal

2. Once a CG is deleted and a new CG is configured with the same volumes, a full sweep is required in order to do block based compare of both production and target and transfer the differences. There's a way to avoid that by using "attach as clean" to avoid the full sweep but this is generally not recommended since then will RP assume the production and target are completely identical without any verification (full sweep).

3. There isn't a limit on the amount of time in direct image access or on the amount of changed data while direct image access.

4. Once direct image access is disabled, full sweep will not occur but a "Long resync" will. This process will transfer only the deltas between the production and the replica.

Hope that helps,

Idan Kentor

RecoverPoint Corporate Systems Engineering

idan.kentor@emc.com

duhaas1 · Answer

1. While in direct image access mode, the changes are marked as a bitmap in the journal

in the journal on the source side i would imagine is where the bitmaps are marked?

3. There isn't a limit on the amount of time in direct image access or on the amount of changed data while direct image access.

so your suggesting those bitmaps have an infinite amount of space?

thanks for the great feedback!

Idan · Answer

1. On both production and target journal while in direct image access. 2. The journals have finite capacity but the bitmaps on those can track changes for infinite amount of data. Regards, Idan

RecoverPoint

Pausing CRR Replication

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