Relatively new to Data Domain administration, so apologies if this lacks information.

To decommission our DD660, I need to move an 8TB (compressed) CIFS directory to a DD670 that is on the same network. Referring to the Data Domain Administration Guide, I prepared a CIFS directory replication session between two DDs on the same local network. I have also redirected the replication traffic over a private network of three aggregated 1Gb links.

Source: DD660 5.2.2.4-370754

Source directory is off of /backup/

Source Date is 8 TBs compressed, and I believe around 25TBs uncompressed.

Destination: DD670 5.4.1.1-411752

Despite this high bandwidth private network connection, the data transfer rate for the initial data copy process appears to be significantly slower then what I would have expected. I have been referring to the 'replication watch' command and the Stats graph view in Enterprise Manager to monitor progress and activity.

The Replication Summery view shows all references for time completion as unknown. About 16 hours into the replication, the 'replication watch' command indicates only 10% of the files have been copied. Assuming this maintained rate, the initial copy will take nearly seven days to complete.

Pet the Status / Stats graphs on source DD:

  • Disk read averages between 12 and 28 MiB/s

  • Private network ports averaging between 1 and 5 MiB/s per port

  • Replication peaks and valleys between 2 and 12 MiB/s

  • The CPU activity for both DDs is relatively light

From the DD Admin Guide and internet searches, I was not able to get a clear understanding of how fast an initial transfer for most replication types should take between two DDs on the same network. However, a few articles indicate transfer rates much faster then what I am seeing.

Some online resources have referred to ensuring the compression type is the same on both source and destination. I have not been able to find this information on the DDs. Other sources discuss increasing streams as well as converting the directory to an Mtree, then performing an Mtree replication. I have not had time to look into these further.

I have reviewed the recent article Replication Sizing Guide (https://community.emc.com/docs/DOC-40889). I have no concerns with the discussed items, but this does support my belief that I should be seeing better performance on this replication.

I would appreciate some feedback on what kind of replication performance I should actually be seeing.

If possible, how might I improve the performance.

Is there a more effective way to copy the CIFS directory data to the destination DD?

Thank you very much,

Bryan