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What “Granular Recovery” in VMware Backups Really Means

Daniel_Hoffer
Not applicable

I have a few New Year’s resolutions: 1) Eat less, 2) exercise more, and 3) share some thoughts around the term “granular recovery” when it comes to VMware and VCB backups. Hopes are high and I am confident I will be able to achieve at least one of my three resolutions.

 

Most folks are already familiar with the “2 for 1” idea behind NetBackup for VMware – the idea that based on a single VCB backup pass, it is possible to restore either an entire VM image or an individual file. This is advanced patent-pending technology for Symantec and no other vendor can do this. However, some of our competitors claim that they have this functionality, while in reality what they have is actually far more primitive and far less useful.

 

The chart below outlines the steps involved in restoring a single 1 MB file from a VCB image-level backup using NetBackup, and compares it to the same process using almost all competitive products:

 

 

Steps for A NetBackup Restore

Steps for a Non-NetBackup Restore
1)      Search catalog (GUI) for desired 1 MB file to restore: (2 mins) 1.       Guess which VMDK file has the desired 1 MB file to restore
2)      Restore file: (1 min) 2.       Restore 30 GB VMDK file from disk or tape (20 mins)
  3.       Mount or recreate the 30 GB VMDK file (45 mins)
  4.       Search inside mounted VM for file (10 mins)
  5.       File was not found; need to search a different VM; repeat process
  6.       Restore (second) 30 GB VMDK file from disk or tape (20 mins)
  7.       Mount or recreate the 30 GB VMDK file (45 mins)
  8.       Search inside mounted VM for file (10 mins)
  9.       If file found, feel good about finding it on only the second try! (Otherwise, repeat steps 6-8 until you find it.)
  10.   Copy desired file to share (1 min)
  11.   Move file to desired destination – process varies (10 min)
Total Time: 3 minutes Total Time: 2 hours, 41 minutes

 

Besides the huge time difference -3 minutes vs. almost 3 hours - there are other considerations too. Often, tapes need to be retrieved from offsite storage (typically, at least 1 business day is required to retrieve and ship each tape). What happens if the desired file is not found on the tape that was retrieved? You’d need to retrieve additional tapes, which could add days (and cost) to the restore process. It’s best if your backup software knows exactly which tape your files are on – and most don’t. (In the chart above, it is assumed that the required tape is on-site, and that a backup client is installed inside the VM in order to enable the restore to occur.)

 

So the advantage of “granular recovery” technology is not just being able to restore a single file from a VCB backup, it is also about fast restore of individual files, which encompasses two things: 1)  “First Try Find” - Find the right file instantly without retrieving multiple tapes and mounting multiple VMDKs until you stumble across the right one that has inside it the file you’re looking for, and 2) Restore without mounting the VMDK file.

 

Not to mention, of course, the additional huge storage benefits that are available by introducing our deduplication technology into the VMware environment as well (either inside the guest VM or on the proxy server).


New Year’s Resolution #3: Complete J   Happy new year!
Message Edited by Daniel Hoffer on 01-07-2009 05:08 PM