We have a setup where we (try to) transfer our backups over a 100mbit WAN link to a remote datacenter. Total primary data is about 12,5TB. Data transferred by daily incremental backup jobs is about 400 GB after deduplication.
Our setup is as follows:
- Local backup jobs are made through a backup proxy. This proxy has iSCSI LUN's for the repositories and direct SAN access to the vSphere datastores.
- We use backup copy jobs to copy the restore points through a second proxy in the remote datacenter. The second proxy uses CIFS shares on a large, shared NetApp C-Mode environment for the repositories
Now, looking at the copy jobs, I see three numbers for the amount of data processed. For example for one of the jobs it says: Processed: 145,5 GB, Read: 145,5 GB and Transferred: 51,5 GB.
I was wondering how much data is actually sent across the WAN between the two proxy servers for this job. Is it 145,5 GB (data is read at the first proxy, sent to the second proxy, deduplicated and written to the CIFS share), or would it be 51,5 GB (data is read at the first proxy, deduplicated, sent to the second proxy and written to the CIFS share)?