This is the setup:
I have a Ubuntu server that is doing the heavily lifting. Its pulls backups from an NFS and puts them on a Drobo device connected via USB using rsync. The Drobo has two seperate shares mounted on the Ubuntu machine at
/drobo2. Each share is made up of two 1TB scsi drives raided using the proprietary Drobo raid. I put daily backups on
/drobo and it takes about 4 hours to do 800GB (mostly large .img files that are copied in full each time). This performance is decent, I guess.
Today I tried a backup that I would like to do monthly; moving the backups from
/drobo2 for longer term backup. This rsync job had been going on for about 16 hours now! This is what I suspect. The data has to travel from the original share
drobo to the server then from the server to the target share
drobo2. Is this the case, and the explanation for the poor performance?