Druva’s Mr. Backup: Why ‘self-protecting’ filesystems are an illusion

Interview File system software suppliers such as Nasuni and WekaIO have built-in backup facilities. They say their customers do not need a separate backup product or service and therefore can save money.

We asked W. Curtis Preston, Chief Technical Evangelist at Druva and a published backup expert, what he thinks about this approach.

Blocks & Files: Nasuni and WekaIO say their filesystem software includes built-in back up and therefore customers do not need a separate backup product or service. Is this a valid position to take or does it create just another backup silo?

W.Curtis Preston

W. Curtis Preston: For what it’s worth, I actually cover this topic in my upcoming book, Modern Data Protection, which should be published this summer by O’Reilly & Associates. The question for me is whether or not they comply w/the “3-2-1” rule of at least three versions on two media, one of which is somewhere else. They can easily comply with the “3” and the “1” of the 3-2-1 rule; I wonder about the “2.” While they can make sure multiple versions are stored in multiple places, all versions are controlled by the same codebase. The concern is that a rolling disaster or creeping bug damages all copies of the data. This can happen and has happened throughout computing history; this is why we back up.

Another thought is to entrust data protection to a company who does it 24×7 and has it as a core competency, versus a company that does it as a side job. It’s unclear, for example, whether or not they have put all the same protections in place that someone specializing in data protection would do.  There is precedent of vendors who didn’t fully understand basic backup and recovery concepts building such features with glaring feature omissions.

Blocks & Files: In that sense they are self-protecting filesystems. Is this a sensible approach?

W. Curtis Preston: The term “self-protecting” has always concerned me. While I applaud native data protection features that make the backup and DR systems a truly last resort, I get concerned when a vendor says their product is so good it doesn’t need backup of any kind.

Blocks & Files: Is this a new idea? Has it been tried before and, if so, how did it turn out?

W. Curtis Preston: I have heard the “we don’t need backup” mantra many times: RAID, NAS, object, SaaS.  Every other time, the claim turned out to be false for some customers. Something went wrong with the setup or the software, and the next thing you know, all your data is gone and there is no backup. A perfect example is the deletion of the private Microsoft Teams messages of 146,000 employees of KPMG in a single mouse-click. Microsoft 365 is another vendor whose proponents often tout their native data protection features.

Blocks & Files: Is NetApp’s ONTAP a self-protecting filesystem with its various snapshot-based features? Ditto Qumulo Core and Isilon’s OneFS?

W. Curtis Preston: In one word, yes. They are the previous iteration of the same concept.

Blocks & Files: Aren’t customers moving to backup systems that provide multi-application backup to a single backup repository? Won’t a self-protecting filesystem work against this idea? For example, a customer with WekaIO and a bunch of applications and systems protected by Druva will find the WekaIO backup is not integrated with the Druva backup (Or Cohesity or Rubrik or Veeam or whatever?)

W. Curtis Preston: Customers have always sought a centralised backup system; that’s nothing new. And yes, this would be a separate protection system not managed by said centralised backup system. These vendors would probably argue that is a good thing, as it probably reduces your TCO and operational complexity. 

Data protection has always been about reducing risks. Some would argue that the risk reduction you get from decreasing operational complexity outweighs the risks of having a single codebase controlling all your storage.  I’d say if your backup system is that complex, perhaps you should consider replacing it with a less complex system, rather than throwing out the baby with the bathwater.

Blocks & Files: Customers are also moving to Data Protection as a service (DPaaS). How would this work with a self-protecting filesystem product/service?

W. Curtis Preston: Any backup system (either traditional or DPaaS) needs an authoritative source to backup.  In the case of these latest vendors, backup vendors would either be integrated with a data protection API provided by the vendor, or use a NAS proxy to monitor and back up any files placed on the local filesystem cache before it is synced to any other places.  

Blocks & Files: Would the self-protecting file system vendors work better with the data protection industry if they partnered with suppliers?

W. Curtis Preston: I think so, and you saw that eventually happen in the NAS world.  First they created NDMP, which gave an official industry-standard API to backup products to back them up.  Then individual vendors (e.g. NetApp) also provided specific APIs that now directly integrate with data protection vendors to make it easier to back up data stored on their filers. It’s important to note that this took 10+ years to start happening.