What happens when the DCM runs out of space?

Hello irobx,
     The DCM is a region mapping of the volume being replicated. This means that it simply tracks changes that occur, and when one does, that region is marked so that once replication restarts, those changed regions can be replicated over.

The more time that passes with replication in DCM mode without replication occurring, the more regions will be marked and ultimately the system could eventually be in a situation where a full resynch of the data is needed, meaning, all regions of the disk changed and are marked for resynch.

Unlike SRL which tracks just the change, in DCM, a 2k change could result in a 64k worth of data having to be replicated over (assuming the region size is 64k). The size of the region is relative to the size of the volume when the DCM was generated so this varies.

I hope this answers your question.

Cheers,
rhanley

Hello,

Thats a good description above, usually tracking changes is very small & virtually you will never encounter a situation where DCM ran out. Even if you see the size of DCM logs which is attached to data volumes is 512 sec. It won't be out of space but yes, all regions marked dirty resulting in full resync.

Gaurav