Lots of vendors use the term “unified data protection (UDP)” without really explaining what it means. One company, Unitrends, has even sought trade market protection for the term. Let’s see if we can agree on a proper definition so we can mitigate this confusion.
We can define “united data protection” as using snapshots plus Changed Block Tracking (CBT) to provide near-continuous backup. That provides for quick restore, which some vendors, in their enthusiasm, call “instantaneous.” Experience suggests no outage is going to be instantly rectified, after all, it takes a little time to size up the situation in the case of a disk failure. Let’s just say it is a many-fold improvement over the old weekly, daily, incremental backup strategy that exposes a business to a long down time in the case of catastrophic failure.
VMware is one platform that supports Changed Block Tracking. Software such as HP Data Protector and VMware Data Recovery can use this feature. VMware exposes this functionality as well to third-party vendors by providing the vStorage API, so other vendors can write backup software for VMware. The idea of CBT makes perfect sense and the term is self-explanatory, so we don’t explain it here.
The two VMWare backup systems mentioned above run outside the virtual machines. On other words, if your computer has 5 virtual machines, each with its own virtual disks, the backup software is installed only one time to monitor all these virtual machines. The VM kernel keeps track of what disk blocks have been changed. The backup software uses the built-in CBT function in VMware (you need to enable it) to access only those changed blocks that have been changed since the last snapshot (i.e. full backup). This brings up the obvious observation that the CBT storage file has to be big enough to contain all the changed block information since the last backup or you have to increase the frequency of snapshots.
We can expand the idea of Unified Data Protection, to include its definition as it is used by Unitrends. The Unitrends software works with the Cisco Unified Computing system, which is an all-in-one network and virtualized cloud offering, Data needed to run applications is not limited to files and programs. Network components need to be backed up as well, as it takes weeks and months of effort to configure these. Unitrends helps with this by backing up both the network and the servers.
Unified data protection is an offering from different vendors to provide near real-time backups for nearly real-time recovery.