I've just recently changed up my Zimbra backup strategy. Previously, I was just mirroring the entire /opt/zimbra directory and had disabled the backup mechanism that is included with NE. However, I found that this can lead to inconsistencies within accounts when a backup is restored, so I've now re-enabled the native NE backup to /opt/zimbra/backup and am trying to mirror this directory using rsync.
My problem is that the sheer volume of data created by the NE backup process is overwhelming my low-bandwidth rsync setup. The rsync goes thru a VPN to an off-site location, but since the locating housing our Zimbra server only has ~2.5 MBit upstream, the transfer speed is very limited.
Each full backup is about 65G, which would take around ~25 days to transfer over the given bandwidth. Daily incrementals are closer to ~200MB, which would not be an issue to transfer daily.
My question is: What are some procedures being used to mirror the /opt/zimbra/backup directory to an offsite location? We're already using the compression built in to rsync, but this provides little relief. While it would be technically possible to have one full backup and daily incrementals indefinitely, I find this a very disturbing solution.
Is there any solution to help rsync in dealing with full backups? As noted by the size of our incrementals, the daily changes are ~200 MB. If we could somehow have rsync only transfer the *changes* between the full backups every weekend, while doing daily transfers of the incrementals, this would be an optimal solution.
Has anyone else had to deal with mirroring of /opt/zimbra/backup over low-bandwidth connections?