Huge .vmdf and takes forever to restore from compressed .sqb

TDawg3TDawg3 Posts: 2
edited January 28, 2013 4:00AM in SQL Virtual Restore 2
Each day we do full backups of all our SQL 2005 databases on Windows 2003 using your SQL Backup product into individual .sqb files using minimum compression (level 1), unencrypted, 2 threads selected under optimization with maximum transfer size set to 1024KB and maximum data block set too 2048KB.

We're very pleased with this tool and haven't touched this process in nearly 2 years - it always creates about 80% compressed backups, on average.

HOWEVER, the few times I've ever attempted to perform a virtual restore, including today, using Virtual Restore v2.3.0.104, it just flat out doesn't work. It certainly doesn't mount to the .sqb files "instantly" with tiny files. but rather crawls and crawls and I see the created .vmdf and .vldf files swell and swell. I eventually give up and cancel.

On a very small database (1.8GB), whose recovery model is simple, the Backup Pro tool creates a tiny .sqb backup (217MB), but the "virtual restore" of this backup took nearly 2 minutes and created a .vmdf of 3.2GB - nearly twice the size of the original .mdf and nearly 15x larger than the .sqb is was supposed to be virtually mounting to.

The "real" .sqb I want to mount to and query virtually is 14GB (original file is 100GB) but, see above, it takes so long and saps so much space, I give up about 1/2 through (which is about 45min later and a .vmdf file size of 80GB and growing with no end in sight - I'm sure it would surpass the size of the original .mdf long before the process ever finished if I were to let it go.

So, what gives? I only read glowing reviews of this product and I've always been happy with the .sqb creation piece, but now I need the virtual mount/restore to work as everybody claims ("instantly" with extremely small .vmdf file sizes).

By the way, it looks like we have HyperBac service version running for the Virtual Restore v2.3.0.104 wizard.

Help! :-)


  • I am the support engineer investigating this issue you have raised. I am really sorry that you have run into this issue.

    I was hoping to get some clarifications in regards to the activity on the system?

    1) Have you always encountered large .vmdf files with this version that you are currently using? Or this has just started happening?
    2) The .sqb backup files are they now being created with a different version of sql backup?
    3) Please also send me the version number the backup files if possible.
    4) If possible please send me the service.log file (located at \hyperbac\logs directory).

    I will be following up in regards to this case via our support ticketing system.

    Thanks for your patience and feedback in this matter.
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