So, we have been doing an some testing on a new backup solution at our company and I wanted to see if anyone had any input. So far the testing has gone well, but I wanted to make sure we are not missing anything before we implement this in our enterprise.
We wanted off-site backups without having to carry the physical media off-site, but still wanted version control. So, what I decided to do was replicate our file servers with DFS-R and use VSS to provide version control at the primary location.
My thought process is that off-site storage of backups and version control are separate processes that get lumped together only because most backup vendors provide both in the same package. However, they really fulfill two different requirements. The ability to restore a file to a point in time (Version Control), and the ability to recover from a major disaster or hardware failure (Off-site Backup).
I started by setting up DFS-R internally at our primary site from one of our file servers to a Windows Storage Server 2003 R2 NAS. Then, I added a server at an alternate location to the replication group that would replicate from the NAS device during non-peak hours. Both locations have fairly high-speed internet connections (10 Mbps), so conceptually we are able to replicate just under 66 GB of data overnight (assuming 8 to 5 work day). This ignores the compression and byte-level replication aspects of DFS so instead of actual rates being less than conceptual rates we can replicate at close to or significantly more than conceptual rates depending on what types of files are on the server.
So, this takes care of disaster recovery, but leaves us in a world of hurt if we accidently delete some files, a file is accidently overwritten, or a file gets corrupted. This is where VSS comes into play. If we set up volume shadow copy, we can recover from deleted or changed files. Now, I know that people will complain because you could lose your versioning if you lose your server, but for most people the cost benefits of this backup solution should outweigh this negative. Also, I have come up with a few other ways to guard against this loss. The first way only works in a virtual environment, but if you are running virtual servers, you can set up your VSS volume on a disk located on a NAS or SAN device that does not host your server disks. Another solution would be to implement VSS in two locations. The last solution would be to use traditional backup technology to back up your VSS volume (You would not have to take this off-site).
I really like this solution for our backups and so far it has been very low maintenance. There are some concerns with the stability of VSS, for example, I have read it can be wiped out by disk defragmenting. However, I have had many issues with traditional backups also so I find that for me the risks are outweighed by the benefits. Besides, spending zero money on backup software makes me happy (Ok, zero money is stretching the truth, I am still working on a solution for SQL Server backups and Exchange).
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