Richard J Anderson

In a previous post I discussed the new backup environment I’ve been deploying, what solutions we picked, and how they apply to the datacenter.  But I also mentioned that we had remote sites with systems we need to back up but I didn’t explain how we addressed them.  Frankly, the previous post was getting long and backing up remote offices is tricky so it deserved it’s own discussion.

Now that we had Symantec NetBackup running in the datacenter, backup up the bulk of our systems to disk by way of DataDomain, we need to look at remote sites.  For this we deployed Symantec NetBackup PureDisk.  Despite the fact that it has NetBackup in the name, PureDisk is an entirely different product with it’s own servers, clients, and management interfaces.  There are some integration points that are not-obvious at first but become important later.  Essentially PureDisk is two solutions in a single product — 1:) a “source-dedupe” backup solution that can be deployed independent of any other solution, and 2:) a “target-dedupe” backup storage appliance specifically integrated with the core NetBackup product via an option called PDDO.

As previously discussed, backing up a remote site across a WAN is best accomplished with a source-dedupe solution like PureDisk or Avamar.  This is exactly what we intended to do.  Most of our remote site clients are some flavor of UNIX or Windows and installing PureDisk clients was easily accomplished.  Backup policies were created in PureDisk and a little over a day later we had the first full backup complete.  All subsequent nightly backups transfer very small amounts of data across the WAN because they are incremental backups AND because the PureDisk client deduplicates the data before sending it to the PureDisk server.  The downside to this is that the PureDisk jobs have to scheduled, managed, and monitored from the PureDisk interface, completely separate from the NetBackup administration console.  Backups are sent to the primary datacenter and stored on the local PureDisk server, then the backed up data is replicated to the PureDisk server in the DR datacenter using PureDisk native replication.  Restores can be run from either of the PureDisk servers but must un-deduplicate the data before sending across the WAN making restores much slower than backups.  This was a known issue and still meets our SLAs for these systems.

Our biggest hurdle with PureDisk was the client OS support.  Since we have a very diverse environment we ran into a couple clients which had operating systems that PureDisk does not support.  Both Netware and x86 versions of Solaris are currently not supported, both of which were running in our remote sites.

We had a few options:

1.) Use the standard NetBackup client at the remote site and push all of the data across the WAN

2.) Deploy a NetBackup media server in the remote site with a tape library and send the tapes offsite

3.) Deploy a NetBackup media server in the remote site with a small DataDomain appliance and replicate

4.) Deploy a NetBackup media server and ALSO use PureDisk via the PDDO option (PureDisk Deduplication Option)

Option 1 is not feasible for any serious amount of data, Option 2 requires a costly tape library and some level of media handling every day, and Option 3 just plain costs too much money for a small remote site.

Option 4, using PDDO, leverages PureDisk’s “target-dedupe” persona and ends up being a very elegant solution with several benefits.

PDDO is a plug-in that installs on a Netbackup media server.  The PDDO plug-in deduplicates data that is being backed up by that media server and sends it across the network to a PureDisk server for storage.  The beauty of this option is that we were able to put a Netbackup media server in our remote site without any tape or other storage.  The data is copied from the client to the media server over the LAN, de-duplicated by PDDO, then sent over the WAN to the datacenter’s PureDisk server.  We get the bandwidth and storage efficiencies of PureDisk while using standard NetBackup clients.  A byproduct of this is that you get these PureDisk benefits without having to manage the backups in PureDisk’s separate management console.  To reduce the effects of the WAN on the performance of the backup jobs themselves, and to make the majority of restores faster, we put some internal disk on the media server that the backup jobs write to first.  After the backup job completes to the local disk, NetBackup duplicates the backup data to the PureDisk storage server, then duplicates another copy to the DR datacenter.  This is all handled by NetBackup lifecycle policies which became about 1000X more powerful with the 6.5.4 release.  I’ll discuss the power of lifecycle policies, specifically with the 6.5.4 release, when I talk about OST later.

So the result of using PureDisk/PDDO/NetBackup together is a seamless solution, completely managed from within NetBackup, with all the client OS support the core NetBackup product has, the WAN efficiencies of source-dedupe, the storage efficiencies of target-dedupe, and the restore performance of local storage, but with very little storage in the remote site.

Remote Site Backup…  Done!!

For the near future, I’m considering putting NetBackup media servers with PDDO on VMWare in all of the remote sites so I can manage all of the backups in NetBackup without buying any new hardware at all.  This is not technically supported by Symantec but there is no tape/scsi involved so it should work fine.  Did I mention we wanted to avoid tape as much as possible?

Incidentally, despite my love for Avamar, I don’t believe they have anything like PDDO available in the Networker/Avamar integration and Avamar’s client OS support, while better than PureDisk’s, is still not quite as good as Netbackup and Networker.

Okay, so how does OST play into NetBackup, PureDisk, PDDO, and DataDomain?  What do the lifecycle policies have to do with it? And what is so damned special about lifecycle policies in NetBackup 6.5.4?  All that is next…