Is vSphere Data Protection the same thing as Avamar?

One of the common conversations in my customer base and among SE peers is around vSphere Data Protection and how it compares to Avamar. It is no secret that the latest incarnation of VDP and VDP Advanced have Avamar technology under the covers: in-line deduplication, variable length block & segment size, leveraging VADP and CBT, etc. EMC and VMware teamed up to bring Avamar technology into the VMware data protection portfolio, but the question is, is it the right solution for a particular data protection requirement? As always, the devil is in the details.

First its worth pointing out that VDP comes in one deployment scenario, a software only virtual appliance where as Avamar can be deployed as a SW only virtual appliance (Avamar/VE), or a hardware based solution (“full” Avamar).

Architecturally, VDP looks like this:

VDP Architecture

VDP Architecture

It is a virtual appliance that runs on an ESX host. One of the major pluses to VDP is the UI is integrated with the vCenter (web) client instead of being an external UI like Avamar. And let me tell you the VDP UI is simple, easy to use and very intuitive — this is a huge win for VDP IMO. The installation of VDP is also very straight forward through an OVF. It should also be noted however that VDP requires the vCenter web client and vCenter 5.1. It does not work with previous versions of vCenter and does not work with the “full” thick windows vCenter client. Under the covers both VDP and Avamar work very similarly and you can expect the same de-duplication rates since they share the algorithm.

VDP comes in two editions: VDP and VDP Advanced. The major differences lie in the configuration maximums, scalability and application level agents.

Each VDP appliance can be as large as 2TB where as each VDP Advanced appliance can be as large as 8TB. VDP supports a maximum of 100 VMs per appliance where as VDP Advanced supports 400 (ofcourse the actual number of VMs will vary based on VM size, dedupe rates, retention requirements, etc… but those are upper limits). Both allow up to 10 appliances per vCenter but each appliance is treated independently meaning there is no de-duplication across multiple VDP appliances even in the same vCenter. VDP Advanced also includes agents for application consistent backup of SQL 2008,2012 as well as Exchange 2003, 2007 and 2010. With standard VDP the only option is an image based backup at the VM level. And while VDP is free with vSphere Essentials Plus and higher, VDP Advanced carries a $1095/CPU list price tag (although it can be purchased bundled through some of the higher end suites).

Now with some of the feeds & speeds of VDP out of the way, here are what I see are the major roadblocks to adoption (especially in my customer base):

First and foremost, there is no mechanism to get the data off-site for diaster recovery or compliance purposes. While Avamar supports both off-site replication to a second set of HW or Virtual Appliance, as well as tape out for off-siting through the Avamar Extended Retention capability, VDP offers neither. There are probably a couple of some kludgy, error prone, labor intensive methods of restoring at a DR site such as by replicating the VDP appliance with array based replication, or backing up the VDP appliance via another backup program which is capable of doing tape-out, but none of these would be acceptable in any of my customer environments. The lack of a clean methodology for off-site recovery would be a deal breaker in almost for almost all of my customers. If you are backing up data that is critical to your business, I don’t see how this could be acceptable regardless of organizational size — and yet, VDP Advanced is being marketed towards companies with 200-300VMs — in my customer base this is HUGE.

Another drawback is in the application level consistency. As a reminder this is only available with VDP Advanced and currently there are only two applications supported — SQL and Exchange. While the SQL agent supports most of the features one would expect, the Exchange agent is lacking a very major one — granular level restore at the mailbox & message level. While you can do a restore of an individual mailbox or message with the Avamar Exchange plug-in, the VDP Advance Exchange plug-in only goes down to the Exchange database level — quite a nascence if all that is needed is a single mailbox.

The VDP backup job scheduling also has a limitations — all backups start at the same time. While the backup job frequency, retention, etc can be altered, there is only one backup window per day with VDP. What this means is that there is no good way to stagger backup jobs. In smaller environments this may not pose a problem, but any backup admin managing size will tell you it is one of the most critical components to keeping backups running smooth — customizing the backup start time of various heavy hitter servers to spread the workload. I see this as a potential point of concern for customers of any size & complexity.

I’ve also heard rumors circulating that VDP/VDP-A can be upgraded to “full blown Avamar” and I am being told that simply isn’t true. This could change in the future, but as of right now its not even in the realm of possibility… buyer beware. If this is an environment that will grow beyond the single 8TB appliance limit of VDP Advanced, and taking advantage of global deduplication across all datasets is desired, it is better to look at full Avamar from the beginning. The deduplication across the entire dataset will bring large efficiencies to the compared to simply deduplicating in discreet 8TB silos.

With all of those things said, I don’t want to make it seem like I feel VDP is a bad product — far from it. It does many things very well: image level backup with file level restore capability; UI integrated right into vCenter; ease of use is a 10 out of 10, and I cannot stress this enough; installation is a snap and the functionality it does provide it works very well AND I feel it is a good value — but as always, its about matching up the requirements with the solution and its important to be aware of the limitations of any product.

If the draw backs outlined above are not a requirement, I would fully recommend giving VDP/VDP-A serious consideration. But while it may have Avamar technology under the covers, it is NOT Avamar.



Categories: backup, EMC, Virtualization, vmware

1 reply

  1. Great read and well written, Thanks!
    Do you think you could restore an avamar backup with VDP?

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